Why Full-Time to Part-Time 4WD conversion is POINTLESS | 4xOverland

The conversion from full-time 4WD to part-time 4WD is a mod based on a myth. Logically, one can save fuel and it probably does save fuel. But it is so little, that any mod to do it is pointless because the fuel savings are so small, and the cost to safety, tire wear and handling is so high that the result is a net loss.
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[@petrbenda3406]

You forgot to mention one rather important benefit of RWD over permanent 4WD - donuts. Donuts and burnouts. Both of them are utterly useless and sometimes even downright dangerous, but the childish fun is priceless.

[@DestDroid]

Andrew it's hard to do donuts and burnouts in 4wd.

[@chrishall848]

put a turbo on, then it's easy hehe

[@brkbtjunkie]

Unless you were lucky enough to have the 1998 5.9L Jeep Grand Cherokee

[@brianmorse8811]

I don't like hearing anyone rant about anything except when it's you, because we share the same opinions! These are my rants too...

[@robkay9227]

Hi Andrew I developed the first part time kit in 1992 for 80 series We did it for because we were have maintenance issues with front drive flanges cv splines and inner axle seals Toyota upgraded these with and update in late 1994 and the problem mostly disappeared after that but the kit continued to sale .Marks 4wd copied the idea in about 1999 . Yes did a lot of dyno tests and discovered that the front half of the drive used 8 kilo watts of power so that may have given a very small fuel saving and the reason the Pajero didn’t is because the front drive train was still spinning . As a side note Toyota threatened to sue me for modifying their vehicle but backed of because the maintenance issues that the kit was developed for were true I hope this enlightens you .now sit down ,take a deep breath and have a scotch

[@Tanner731]

even dyno tested the mod to prove it worked thats great!

[@alexmaguire2596]

Oh man, this bloke needs to calm down!!

[@robkay9227]

I think possibly he regrets buying a vehicle without having it checkout first and needed to pick on something To his credit he has show us the build in full even if it make him look a bit silly for not getting checked out Great showcase for Terrain Tamer which is a good Australia business I have dealt with for many years

[@olcock6007]

@@robkay9227 Even that is no guarantee, mine was check out by the same people and cost me allot. Problems after problems. $$$$$$$$

[@peterbarber7613]

Rob Kay.the 80 series came out with a part time 4wd

[@84shortyota]

I like my part time conversion on my 80 series. I didn't do it for increased fuel mileage. I did the conversion so i could run an automatic locker in the front axle. It was cheaper to buy the conversion kit and BOTH lockers than it was to buy one ARB locker, let alone the compressor. I like knowing that my lockers will ALWAYS work. I don't have to worry about air lines leaking or anything like that. I see no strange tire wear and the steering is a little lighter which isn't necessarily a bad thing. There's less wear and tear on front end components.I also like driving on the trails in 2wd until 4wd is needed. All i do is hit that center diff lock button and i'm ready to rock! Its just more fun!! I have had absolutely zero ill effects of doing this "mod". Each to their own!

[@davidcoy8348]

It's nice to see a video from someone who is NOT at SEMA.

[@stevjosco.adventures]

Thanks Andrew, I was seriously considering installing a part-time kit in my 105 in the hope it would improve fuel economy. You have convinced me that I would save more money by leaving it as it is... a big, heavy, full-time 4WD. If I really want better fuel economy I should get a Jimny and camp with my hiking gear, like I did in my 20's in my 1978 Suzuki :D

[@hiteck007]

I disagreed with him, read my explanation above. I had both constant & part time 4WD & kept the parts to convert it back if it was no good. I never converted my rig back because most of my driving is highway use & only need 4 WD on occasions. Not having a 2nd diff running Improved my overtaking capability out of sight, it's night & day difference & yes I drive a notable 50 km farther on (roughly depending on driving style) a tank on highway use but in the bush 4 WD or 2 WD fuel use is near on the same, that's the real story from my 1HD-FT Auto.

[@jeffh7021]

Every time I hit dirt rd I just pop it into 4 wheel automatically. It always feels like the passenger disagrees. Thinking...already? You've put it in 4 wheel? We dont need it. I eventually explain what you just ranted about. Love the work Andrew. Keep it up!

[@keithhaycraft3765]

Dirt roads are what 4wd high is for, it says so in your manual & earlier Toyotas had it on a sticker either inside or outside the glovebox lid.

[@krover01]

That's the beauty of full time awd with locking center diff. I can hit the dirt road and be fine in awd. Things get tough I just lock the diff.

[@scod3908]

Exactly, put the part time 4wd in 4H as soon as you're off the tarmac and all his rants about handling differences become moot...

@@scod3908 well if it's wet, 4H (AWD with open center diff) is an advantage even on tarmac, isn't it?

[@scod3908]

I'd rather drive carefully in the rain like every other RWD vehicle on the road and know that I can get out of trouble when I'm in a remote area which is what a 4wd is supposed to be for.

[@walterashby1816]

I do agree. I have fitted a lot of these part time kits into the 80 and 100 series land cruises for one reason only. The repair costs to the drive train when towing large heavy loads. The landcruiser is a fantastic vehicle but the full time 4x4 is week in everyday towing and the repair costs are heavy replacing CV joints outer drive flanges,the repairs to the front diff head and transfer case on a on going basis. So a lot of customers either traded for a 70 series landcruiser or a Nissan patrol or we fitted the part time kit which made them comfortable to drive and eliminate the maintenance costs

[@JFK786]

Agree. This point was not covered in the video.

[@ajphillipsracing]

Walter Ashby the ability to engage low range on a boat ramp without braking anything is a great advantage as well. Just generally more options!

[@schrinky90]

@@ajphillipsracing or backing trailers and vans up driveways

[@randycarpenter2914]

Love to listen to your information. I live in the states and owned a 1978 4x4 with the np203 full time transfer case. It was my dream truck and I loved how it would go on mud or snow and ice covered roads. I seldom locked it into 4 wheel lock because it seldom needed it unless I was in a rough place where I wanted to just creep along slowly. It finely wore out after 30 plus years. I was the second owner and replaced the motor once and had the transfer case chain and gears replaced due wear over many thousands of miles. I now have a 1994 ford f150 4x4 with rear wheel drive only unless you lock it in. It is the most helpless truck I have ever seen. I was so used to just being able to drive not worry if it was a little mud or snow or even wet grass and on wet roads it hydroplanes in the rear so you have to drive slower and always worry. I agree I have not seen the difference in fuel mileage difference, but the difference in how it handles is very evident and I think all 4x4 trucks and suvs should be full time transfer case for safety. Thank you and loved the video. Its only my opinion for what that is worth.

[@lanceroark6386]

Andrew, I’m a truck driver here in the states, so that’s where I get my experience. Fuel consumption comes from weight first (almost entirely actually), and aerodynamics waaaaay behind. The only reason that a 4wd truck gets “worse” consumption is because of the added weight. I put worse in quotations because it’s only worse when one is ignoring capability and safety. Given the increase in capability and safety, the cost of increased fuel consumption is more than acceptable.

[@DriveOnLeft]

As an Automotive engineer in the industry, part time does save on fuel. Not in the litres/per hundred however, more so in the 0.1 litres per hundred. You have to understand with new Euro emissions, saving 0.2 litres per hundred is massive.

[@IISIDESWIPEZII]

100 series V8 literally saves over 1L/100km. Since the conversion, I get 40-60km extra per tank.

[@waronwoke]

This guy talks from vast experience and not trying to sell you anything, a refreshing change.

[@fastnet4x4]

When recovering a vehicle, the part time system allows you to use different combinations. Sometimes we do not want traction on the front wheels or sometimes we just want to place the reduction gear without activating the front transmission, for example in areas with very tight turns. Part time its most versatile.

[@GRcorolla-bt3mn]

Can you give any example of one such particular scenerios where you don't wanna send power to to the front wheels?

[@ceejfletcher]

It would not make a difference

[@IISIDESWIPEZII]

@@GRcorolla-bt3mn when I’m off-road and I break a front axle, then I get put it into 2wd and drive it home. Also, will save a small portion of fuel by only driving 2 wheels. Also, the vehicle becomes easier to steer when the front axle is not being torqued. This muppet has no clue.

[@GRcorolla-bt3mn]

@@IISIDESWIPEZII hmmm makes sense

[@hongmihnhahn7081]

Sometimes we do want all traction of tire but not 1:1 traction!. AWD is also needed

[@brianwalker1933]

Well said Andrew!! I’ve been driving all sorts of 4WD’s since 1978 and l drive them just as you do. I leave the “free wheeling hubs” in the locked position and when l leave the “dry” bitumen, l select 4Hi or 4Lo as required. Safety is “paramount” to me, at all times. Keep up the good work mate...you’re the man.😊👍🇦🇺🦘

[@mazevx2451]

Woke up this morning and saw the notification of this video and watched it. It's refreshing. Thank you Andrew for being the way you are! Besides the fact that you are completely right on this.

[@jasonwooler801]

Also don't forget you get better fuel economy by going north to south in the southern hemisphere. Why? You're going downhill............

[@willactually7509]

Yeah, but more tyre wear on the left because of the Coriolis effect!

[@JohnDoe-hy2op]

When I was a yougin I thought the globe was just convenience, because its obviously not a globe, only if you look at the TV or go to school it is a globe, in the real world, it's flat, and we need to go back to the drawing board when talking about part time 4x4 conversions, wear, and consumption. 😆😂🤣

[@ElisPalace]

The earth's constantly spinning sometimes we on top sometimes we on bottom

[@JohnDoe-hy2op]

@@ElisPalace that's what everyone says but to me it looks still, and it's all the lights up in the dark are moving or what's called the sun in daytime.

[@catchawakeup6411]

Not true! The earth is flat

[@timetogodoug]

Thank you Andrew, have a great day!

[@sweethome7374]

Thank you Andrew. Was considering this for my ‘97 80. Appreciate the content and Happy New Year!

[@shawndavenport2236]

Thank you for giving your experience and observations! You couldn't be more correct. I drive daily on snow, ice, sand, and asphalt (tarmac) and wonder every day why my truck has a part time system. I constantly have to switch from 4wd to 2wd because of changing road conditions. I wish I had a full time conversion. Keep up the good work! Cheers from the USA!

[@scotttate7012]

Thanks Andrew! This is encouraging! As the owner of a full-time 4WD 100 series land cruiser (US spec) I think I will spend my money on other modifications instead of a 4WD to 2WD conversion.

[@debrown4093]

MY company every 3 years would replace MY f 250 4x4 or f 350 4x4 part time. I would alway lock the front hubs for the first 2,000 miles to ware in the grears and bearings. Then run unlocked on pavement, then lock them when running for miles off pavement. I noticed on measurable differences in fuel milage.

[@ewingfox6459]

We grew up with the same trucks and also saw a pretty significant fuel savings when in free spool as well with the f-series trucks. plus, it meant that the kid who got the window seat also had to jump out in the snow and flip the hubs where the kid that got stuck riding in the middle (who we get whacked in the knee every time his old man shifted into 2nd and 4th gear) at least had dry boots when we got to school! ;)

[@jailbreakoverlander]

Lets be accurate you dont build them, you watch them build it, second I just finished making my 97 FZJ80 from AWD to part time with aisin hubs and 300 m inserts mated to RCV 300M axles and a marks adaptors spool. the part time allows better mileage MUCH less wear and tear on all moving parts up front. and a birf goes unlock and roll. So your wrong homie.

[@craigice9635]

Your better mileage saving will be a fraction of the cost of the conversion. I know with the FZJ you'll be looking for every bit of fuel saving, but you'd be better off with a diesel. I did enjoy the power though, but paid severely at the pump.

[@bamacruiser149]

Yep, AWD sucks. Converted my 100 series and never looked back. I also have a 4x4 sequoia with normal 4wd. Don’t know why the hell they didn’t make it like the sequoia with coilovers.

[@bamacruiser149]

Craig Ice kit was around $600, more power and lighter steering. Well worth it.

[@jeep6242]

"Much better mileage". Please share with class what much better mileage means with 37" tires, a huge lift, and an RTT? I love your rig and am starting to enjoy exploring your channel. But c'mon, the aero load alone on your rig is like 500X whatever infinitesimal gain in consumption would be from not spinning the front drivetrain stuff. It's just not credible.

[@dominicevans7430]

Dontwant to run the rcvs with full time it will wear them out really fast.cant wait to get some for mine

[@tbillington]

Can't drift around a wet roundabout with constant 4wd though ☹️

[@leskobrandon538]

4 wheel drift?

[@danielperdikis5598]

Yes you can!

[@G55STEYR]

You just don't have the power then

[@ElisPalace]

@@FlatlanderGear what 4x4 these days come with free wheeling hubs besides 70series

[@kleinbiker1]

Sure you can, you just need more power.

[@slateslavens]

And the other benefit of running with the front drive parts engaged is that they stay properly lubricated - the CV/U-joints at the steering knuckles, the front propshaft joints, and ring & pinion bearings, etc. I've heard arguments about this causing "premature wear" on the above-listed parts, but they aren't going to wear any faster than the rear parts. That said, a common problem with Land Rover Discovery IIs is that the low-range lever seizes up. This is because it's so rarely used. The same goes for the entire front drive train. If you want it to work when you need it, it needs to be exercised. A system that doesn't get used until it's needed is far more likely to fail under pressure than one that is always in use. Andrew, I'm with you. /rant off

[@MrApple187]

Lies my bmw x drive has been rwd for 5 years no problem

[@slateslavens]

@@MrApple187 yep. and your front CV boots are probably dry-rotted. They'll fail soon after using them again and if you don't catch it, the CV joints themselves follow shortly after. And what happened that you've never needed four wheel drive in five years? Dude, get out on the tracks and have some fun!

[@MrApple187]

@@slateslavens I need a little lift first going to be doing x5 front end swap but I guess not the whole 5 year I use the awd once in a while like just a couple months ago I got it stuck in sand and was struggling to push it lol till I remembered and I plugged my transfer case actuator lol and hot it out but i use it once in a while but on the street it runs rwd

[@slateslavens]

@@MrApple187 cool! Shoot some video while you're doing the swap and post it up!

[@henkstols9326]

I have a Triton with super select and have never liked 2H, I tried driving a couple of days in the 2H mode and vehicle did not feel as stable on the the road. Fuel wise I would rather have a more stable vehicle than save on 1lt per 100km.

[@CACressida]

I had a 2002 Toyota 4Runner with what Toyota called multimode 4wd which allowed you to drive in 2wd, AWD or part time 4x4. I drove it a month in AWD and noticed 0 difference in fuel economy. Driving improved greatly on twisty roads and acceleration from a dead stop when turning onto other roads was obviously improved. Because of fulltime awd there was far far less intrusion from the Vehicle Stability Control which was notorious for cutting engine power in 2wd because of a little bit of wheel spin. I wish I had that system in my FJ Cruiser because I found it extremely useful.

[@thedirtlifesupreame]

I've driven a Land Rover with just Rear Wheel Drive. It just doesn't feel right. They drive so much better with full time four wheel drive.

[@sampaulus2001]

Andrew, I'm not the kind a guy who comments often on videos in general. this time though I completely agree with your "little rant". Thanks for being so honest and passionate in your videos.

[@leonardpadin869]

Completely agree with you Andrew. Just got your Four-Wheel drive book. Guess I get to reading this beautiful Friday afternoon. Cheers from Las Vegas!

[@markholtan5696]

That was a fantastic video and made clear one of the things I rant on about to other people about my 1994 80 series Toyota . It’s not worth the money for the conversation and you get nothing in return except a less capable vehicle.

[@garthhayward9581]

As I understand it Part time 4wd like the old jeeps combined with manual locking and unlocking wheel hubs will save on wear and tear on the front axles and diff internals as they wont be spinning. So when it's disconnected in 2H the entire setup isn't spinning and therefore an argument could be held on that point. However it is important every now and again to engage these parts to ensure they are getting lubrication and that bearings aren't consistently riding on a static position.

[@MegaMr28]

it also stops the classic landcruiser driveline cluck

[@hanrahi9030]

Actually, this argument is logically invalid. The difference in wear & tear savings over a span of 100K miles is negligible. But more importantly, why do you think saving a few negligible miles of wear and tear in the front drivetrain is more important than the REAR drivetrain???? The rear is spinning all its life, so if it can survive that then surely the front can handle it too.

[@ZuluGoatHerder]

@@hanrahi9030 I’d much rather just run on the rear diff and repair rear diff than all the extra work in constant maintenance in swivel hubs and CV joints - ever done that work yourself?

[@hanrahi9030]

@@ZuluGoatHerder - Well, you are arguing for 2wd on a 4wd page. Whether I do the repairs myself or pay someone to do it is besides the point. A rear diff typically doesn't break down even after 200k miles. If my front diff lasts for 180k miles, that is still a good deal.

[@nirfz]

Absolutely agree, but there are few things to be mentioned: First: 2wd means two tires have to transfer all your torque to the ground while 4wd means 4 tires transfer all the torque. -> 2wd: 1 tire 50% of the torque, 4wd 1 tire 25 % of the torque. And in slippy conditions that means slip will occur "later" (or you could say you will come further). Second: Audi when comming up with the first quattro prototypes found out that it increased fuel consumption way less than calculated. They tried to figure out that a wheel that gets powered has less rolling resistance than an unpowered wheel. And lastely to the safety part: engaged part time 4wd or a locked center diff can be dangerous when braking hard on slippery gound: The front wheel brakes usually have around 70% of braking force. That means they lock up when the rear ones would still turn and be able to transfer braking force. But with both axles locked together, if the front axle locks up, it locks the rear one over the 4wd system too. Thats why people who drive on snow in the alps usually put part time 4wd cars in 2wd when going downhill on snow.

[@zeMasterRuseman]

I did the part time conversion on my 80. The steering is lighter, and there's less backlash due to less parts spinning. Plus touring in Australia means 1000's of ks on bone dry bitumen where you don't need AWD at all. Overall though I could take it or leave it. If I had to do it again I'd probably leave it alone.

[@jimtekkit]

I get the opposite. My ute has backlash in 2WD and has none at all in 4WD. It all depends on where the backlash is coming from.

[@nirfz]

May i ask something? (i am not that familiar with such conversions) When you say "part time conversion" does this mean it then works basically like the 4wd system of a Jeep Wrangler? ->you eliminate the center diff, and put a form of coupling in that you can close to swithc to 4wd? So that there is a strict connection between the two axles. (like a locked center diff) but when you open it, no power goes to the front wheels?. Because if that is the case, the same parts are turning if you switch to 2wd. They just don't get direct power by the engine, they get turned by moving the car. (so you get loss from the power having to go through the wheels over the gound to the front wheels.

[@stevep8773]

@@nirfz It's been many years since I had a Jeep, but they used to have Command Trac (4WD) and Select Trac (AWD, IIRC). One was 4WD and one was AWD. Your basic 4X4 has 4WD but it only works well on loose surfaces since there is no centre differential - only a transfer case. If you drive one of these basic "part time" systems on tar, you get windup (axles storing energy from travelling at different speeds) and tyre scrub as the energy is released on turns, etc. Accelerated wear and weird tight steering result. On AWD or "full time" 4WD systems like LR Defenders, there is a centre diff that is normally "open" so the F&R axles can travel at different speeds but still get drive (also you have the regular axle diffs that allow L&R wheels to differ so you can go around corners). This can result in more settled handling and less tyre wear. But you could still get stuck with only one wheel losing traction as all the other diffs are open. Hence the need to lock the centre diff (and on LC's you can lock the axle diffs as well). A locked centre diff means you have to lose traction on both axles (at least one wheel) to be stuck and locked axle diffs mean any one wheel can deliver power (whether that's enough to unstick you is another matter). And then you have the traction control computers (selective wheel braking) and so on. As fas as fuel consumption, none of this matters much (as ASPW discusses above) when you look at the mass of these vehicles, their load and especially the effects of wind

[@gw5436]

Impossible mate. The internet experts disagree!

[@nirfz]

@@stevep8773 I am familiar with the theory of how that works, i wrote that i am not familiar with the conversions. So i wanted to know what his conversion inlcuded. As for the Jeeps, as far as i know the Wrangler never got an awd system with center diff. It to this day has a part time 4wd without center diff. That's why i chose it for the comparisson.

[@randomoldbloke]

This is one of the few times that I agree 100% with Andrew! Most of the comments for converting to part time are so easily counted with fact not just opinion

[@shanerlawrence]

Andrew so i have a hilux 2.7i 4x4 and as i understand now is that i can lock the hubs and drive it to get all the parts to work and lubed? I was under the impression that i might brake someting, thanx fir your advice

[@4xoverland]

It only can damage something if you engage 4wd on asphalt. You MUST run in 2wd on asphalt. But run it in 2wd, with the hubs locked as much as you like, and whenever you like. It also important to do that now and again to make sure everything gets lubricated.

[@foxxmufasa]

Why can’t I find that shirt you have on available for purchase on your website?

[@ihavenottheslightestclue]

What about if you break something in your front axle? A massive advantage of a part-time kit is the fact that you can unlock your hubs and stop the front internals from spinning and causing further damage while you limp your way home.

[@robertclark2714]

That is a $500.00 luxury that you probably will never use.

[@don0612]

I’ve wished I had it twice. Would’ve saved me thousands

[@corhendriks1755]

What if you break something in your rear axle, or gearbox, or have a heart attack, or if your wife dumps you?

[@redneckwithajeep5001]

That's a good point however you can generally still disengage the front. Take the drive shaft out and depending on setup the CV shafts can come out. Now on a solid axle vehicle that's another story but most modern vehicles don't have a solid axle. If you need to you can generally limp something off a trail to a tow truck

[@tommiller5759]

Hi, I want to start off and say that this just video just saved me a lot of money by convincing me to not do the conversion. THANK YOU!!!! I also wanted to share that a mid 80's Chev Blazer with the hubs locked but the transfer case in 2wd will use about 3 more mpg then when they are unlocked and you can feel the wheels fighting the steering wheel while going around corners.

[@samuelrivera2391]

Helloooo== do you think I can convert a 2wd Toyota 22r transmission into a 4wd do you know some way to add the transfer case

[@duncanwallace7760]

good to hear this, I leave my delica in 4x4 all the time because of safety and tires. I decided that the 'extra' fuel was worth it, but if its not using more fuel, then its definitely worth it!

[@Auribus]

As others have said; the point of fitting part time 4x4 is that it gives you the ability to isolate the front drive train if it gets damaged on the trail. Unlock hubs and transfer in 2wd makes the front prop, diff and CV's stop spinnig when driving. That way you can limp home and repair. Broken CV or front diff on permanent 4xd means you are up shit creek and have to repair in situ or drive on damaged components risking further damage and/or steering lock up from your CV's exploding. Removing the front propshaft and locking the center diff does not help, CV's and diff are stil spinning on a car without free wheel hubs.

[@willactually7509]

Exactly! This is what Andrew and the majority of those commenting here do not understand. Plus, the rotating mass of differential gears and side shafts rob power, and will cost you in fuel consumption.

[@ewingfox6459]

I love the feel of AWD (vintage Audi guy) BUT in my Jeep - I broke a rear driveshaft and was able to lock my front hubs, disengage my RWD (twin stick transfer case) and got home driving the only front wheel drive 454ci Jeep :)

[@willtricks9432]

Series 3 Land rover, half shaft snapped in traffic, popped into 4WD and away on black top, No free wheeling hubs so did it from my seat. Cheers

[@Taun1000]

You can do this in a permanent 4wd as well, by locking the center diff, and removing either the front or rear propshaft

[@Auribus]

@@Taun1000 Removing the front propshaft and locking the center diff does not help, CV's and diff are stil spinning, driven by the wheels, on a car without free wheel hubs.

[@woytovich]

Andrew.... I know this is an old video but I have a related question that you might have an opinion on: I'm swapping a US Spec 2UZ v8 and an Australian H151 manual 5 speed (with original transfer case, both from a 100 series) into a 1966 FJ45LV Land Cruiser. I will be running a 1978 era 40 series front axle (the 40 was a part-time 4wd truck of course). Given a full rebuild with new parts on the front axle do you have any reason to believe that it would be a bad idea to run the front axle with the full time transfer case (rather than converting the TC to part time to stick with the original set-up for that front axle)?

[@carloborromeo5595]

I have a 41, at High (2wd), my front propshaft always spins at 2H. Is this normal? I know for a fact, it came with a vacuum actuated front locking hubs but, later on the hubs were replaced with manual locking hubs. Could condemning the vaccum system somehow also had left the front propshaft to always be engaged somehow?🧐🤦‍♂️🤷‍♂️

[@robertchestnut3331]

I am glad you posted this video. I own a 1991 fj80 and was thinking about this mod but was on the fence about it. now I am going to save money for something else. thanks!

[@JeremyPetho]

There are other good reasons to do the mod apart from fuel consumption

[@mondo_stunts27]

I did the part time conversion on my 2000 LC v8. It really helped the car feel better on dry pavement. I only have 33’s and it handles so much better. Tighter turning circle, transmission seemed to shift smoother, steering feels a littler lighter. The down side is I do have to pull over half way up the canyon to lock the hubs if it’s snowing bad. The other is with open diffs and no limited slip, in it’s basically 1 wheel drive on ice in 2x4. Another upside is it should wear out my ifs cvs a lot slower.

[@SuperHamKaas]

I just bought a '94 80 series HDJ80 4.2 1HDT which was originally an auto but converted to a manual transmission which I found out later.. The manual transmission in this is no longer full time 4WD but 2WD on the rear when in high range, and 4WD with the center diff locked when in low range. So the issue I have here is that I am missing my high range 4WD. I wanted to solve this problem and bought an OEM center diff lock switch which is an option on some 80 series as far as I know on these models. But it seems that the electrical wiring to the transfer gearbox is missing on my model for this option. Does anyone have any ideas in solving this?

[@TheLansang]

When on 2wd mode, is the front end lighter when taking off from a dead stop? I will be supercharging my 2UZ and would like to take advantage.

[@Nagudin]

Just couple days ago change part-time tc to full-time with VCD on my 80 series, and now I'm absolutely happy.

[@simplemanduke7128]

Thank you for the rant. I enjoyed the information and the real world test results. Keep up the great work.

[@creigmacc]

Until the argument looses traction it's going nowhere... 😁

[@mark2073]

I get it

[@Michael_Mears]

I see what you did there.

[@johanvanderspuy7256]

Gripping stuff

[@Tanner731]

just wait till it loses a CV shaft

[@intimatespearfisher]

You’re just winding him up 😃

[@gilbertarnold8666]

Great video thank you!

[@maxcole1961]

Great information Andrew, thanks

[@BittnerBuddenbrock]

I have been driving off road and in all sorts of weather conditions on 4 continents for 50+ years and I agree 100% with Andrew's points of view and explainations!

[@jacks86australia]

Old man yells at clouds

[@JSJensen]

OMG that's so original!

[@7thpostvideos449]

Most SUVs hardly need the use of 4wd in real life. For example, my pajero goes off road about 10 days a year. In this regard, my experience is that the part time 4wd (2H) makes the front parts of the drivetrain (ujoints, front diff, CV joints, CV boots ect) wear less. In my pajero, haven’t touched them since I got it 10 years ago. Another experience I have is, in a Hilux (2002) with IFS, the CV boot was torn and the vehicle has run in part time 4wd with manual locks open for a very long time. But this has not damaged the CV joint as it was not rotating. A bit of cleaning and a new CV boot did the job. I could be wrong but don’t you think 2H make sense for vehicles that hardly go off road?

[@pauls4708]

Be careful there afaik the pajero uses a disconnecting front diff which means all the front stuff is spinning all the time

[@tomkarlsborn2384]

Hi. I have a Pajero also with Superselect system ie 2H, 4H, 4H Lc, 4L Lc. (Lc=Locked centre diff). Using 2H the front driveshaft is not powered but will be driven by the front wheels rotating UNLESS you have either Auto Locking Hubs or unlocked freewheeling hubs. In this mode you may see a slight improvement in fuel consumption. The trap in this mode is that stupid owners leave it in 2H forever and the parts will deteriorate unless turning. Rust in diff, seals sticking, CV joints drying etc. Use 4H now and again to avoid this. My preference is 4H 100% until offroad when 4H Lc/4L Lc is the go. I feel the car handles better in AWD (4H). Cheers

[@matschroeder1184]

I recently had the front prop shaft out of my 2003 Grand Cherokee which is full time 4wd, I did notice a tighter turning diameter(handling?).

[@daveslater6156]

I have a WJ Grand Cherokee. 4all is a misnomer. The Quadra Drive system is rear wheel drive unless one of those rear wheels starts slipping. At that point the gerotor in the centre diverts power to the front axle in a progressive manner. It is only proper 4wd when in 4low and the centre transmission is locked.

[@Nick-im3sm]

Interestingly, I've done this very same test, in 4 different 4wd trucks I've owned. My second ever 4wd was a 1996 Jeep Cherokee 4.0L country. It had a multi select transfer case like Mitsubishi has where you can go 2wd, open diff 4wd, locked diff 4wd HI, neutral, Locked 4wd Low. I drove that thing for almost a year on normal roads in 2wd before one day thinking "Hmm.. I should try out the full time 4wd" (this truck had a limited slip center diff, so it was a good 50/50 system) I had been measuring my average fuel consumption over the prior year at roughly 15.5mpg (I still have the records on it and every truck I've owned) So I tried full time 4wd. There was basically no difference. Roughly 15.5mpg is what that truck was destined to get no matter what the lever was set at over the course of a month. So I left it! Why not? It's was more sure footed in crappy conditions, and locking the center diff just required one click up on the lever vs 2. Later on, I'd have a 1981 Toyota HiLux (22R, 5 speed transmission, part time 4wd with lockout hubs) As soon as I bought the truck, I decided to test it to see if the hubs being locked vs unlocked made a difference, and it made zero. The only thing on that truck, was if in 2wd, you could feel extra vibration while driving with the hubs locked, which I attributed to something being perhaps worn out, but I was never able to track it down. Further down the road, I had 2 different Chevrolet Suburbans, one from 1989, the other from 1991 (2nd was a 3/4 ton, so solid front axle, lockable hubs) Both trucks, tested and found the hubs being locked made absolutely no difference in fuel mileage at all. That 91 suburban was my final part time 4wd vehicle after that, as I find the full time 4wd is just a safer all around option in wet weather/snowy weather. My 1996 Land Cruiser 80 was effortless in all weather, and my current 2008 Land Rover Discovery 3 is perhaps even more so, because of clever electrics (which I know you kind of loathe, but I've conquered that fear via programming) Great video, and great discussion!

[@willactually7509]

Have you considered that your '96 XJ, whether in 2wd, 4wd part time or 4wd full time, the front drive shaft, differential and side shafts still spin together, and for that reason you will not notice a difference in fuel consumption? Fitting free wheeling hubs and select 2wd will get you up to the high teens.

[@Nick-im3sm]

Will Actually I have considered. But I’ve also had vehicles with freewheeling hubs and it’s made zero difference.

[@scottcampbell2836]

As long as low range is there i can make either system work

[@thesheepman220]

I have AWD central diff lock , thank you Andrew

[@AdnanKhan-ky3jp]

Your explanation was fantastic. It made clear so many points in my mind, thank you. From Canada

[@roddybasha69]

it's a rant, but I love the way you put them out, always have time for you

[@seumasmackinlay]

Also in agreement with you, Andrew. Thanks for the rant. 😁

[@user-iq7cd3ub5h]

I love your honest review😉👍🏾👍🏾! What you said does make sense 👌🏾!

[@joashtunison351]

Muchas gracias, Andrew! My 79 jeep wagoneer shall remain full time quadra trac, a decision I already made but which you have nicely backed up.

[@raybulmer5707]

Well put!!!

[@Mack74]

I'm wondering one's who have added a third party ie marks part time kit to there full time 4wd. Would they be uninsured as they have modified the mechanical system unless they get it plated ?

[@franklowe3798]

Thanks Andrew for all you great content , I just love your shows . I drove the dirt high highways of the flinders ranges last year and 4wd definitely improved my handling in my 2008 triton ,around bends ,wild life ect. I did notice minor extra fuel consumption. but I must say that the improved safety factor that comes from the improved handling due to 4wd on loose surfaces far out weighed any fuel consumption concerns I had previously . I think the main reason folks do this is because of driveline slop which ultimately becomes problematic due to partial binding of he whole system leading to a failure , I wish we people all possessed a hard core mechanical sooth sayer like knowledge , at the exacting moment when the individual makes their misguided decision based on an uneducated fix that they may have read or had heard about . This will and happen perpetually also as this kind of mod is determined on a personal & emotional conception . Considering all the associated affordable aftermarket parts that are available . Maintaining a vehicle in a cycle of perpetuation ,will always have its pros and cons . I have a firm attritional belief in all my perpetual maintenance on my most important work rest and play asset, the vehicle , my maintenance beliefs were all hard learned, as I drove boxes of turd for many years with very poor maintenance management & whilst not by being influenced by others I just believed I knew better. For myself and a lot of others , perpetually maintaining a vehicle or boat or trailer is half the fun of ownership , having to make those all important decisions to either upgrade ,modify ,or repair ,replace , whilst Juggling an almost non existent budget, Ooooohhhaaarrrrgh the joy . Sometimes wifey can tell when I try to pull a swifty over her to hand over our hard earned ,and ( want) to upgrade and purchase my 35” tyres instead of the (need) to replace the clutch, we all have these absolute requirements at the time ,even if it’s painstakingly obvious it’s not the right decision at the time. Love the non biased content ,

[@MadMatt4WD]

Excellent video and you’ve said what I’ve always suspected.

[@duncnz3129]

WW2 Jeeps has a disconcerting habit when in 2wd , of not always going around corners and turning the steering wheel suddenly at speed could make the vehicle turn over .The US Army got an engineer named Warn to find out why and fix the problem , he discovered inertia of the extra rotating mass of the drive shaft , axles etc , in some circumstances, caused the Jeep to become reluctant to respond to steering wheel inputs and want to go straight ahead . He came up with free wheel hubs , which were turned in or out by a spanner , after WW2 he left the Army , he came up with hubs that could put in or out by turning a leaver on the hub . I have an Aussie mate who had a Land cruiser 100 series , he had the full time 4wd changed to selectable 2-4 , he said in black cotton soil areas of Australia at some times of the year it was illegal to use 4wd on the dirt roads , True or not ?

[@johnpeake-livingretired]

I driven the Audi A5 4 wheel drive and then the A5 2 wheel drive , wow I’ve now going after 4 wheel drive , save money on fuel and tyre wear , soon both my cars and 4x4 will have all be 4 wheel drive , never going back, love them all !

[@markharris9040]

Well, you saved me some time and money! I didn’t want to try and fail so I just needed that push in the right direction to get me off the fence!👍

[@terrymoore9185]

Maybe I missed it?, but I didn't hear a test with the front hubs unlocked and the lever in 2wd. Without all the front components spinning for no reason it would seem you could save on fuel?

[@4xoverland]

Logically, one can save fuel and it probably does save fuel. But it is so little, that any mod to do it is pointless because the fuel savings are so small, and the cost to safety, tire wear and handling is so high that the result is a net loss. It's a myth promoted by companies selling the kits.

[@billchesser1475]

Andrew, I have a question. Both my 4-runners (Prada?) have had 2wd, 4Hwd and 4Lwd. Whenever I’m on dirt or gravel roads I put it in 4Hwd. However on pavement I keep it in 2wd because it handles better. Are you suggesting to drive on pavement in 4HWD or are you only talking about vehicles that come from the factory with permanent 4WD or AWD? In regards to making major changes to a vehicle, I believe the engineers are generally smarter than I am. Even though my first 4Runner had five speed manual transmission and my current one only has four speed automatic transmission which is much worse.

[@lwysparagon8109]

If you have 2wd selectable I assume your 4wd mode is part time ( should be true for all models and countries 4Runner?). It's not recommended to use part time 4wd mode on dry road but if you're familiar with the feeling you may engage it on wet road. The explanation of how to use 4H is "whenever your car is on the loose surface, you're able to engage part time 4wd since it won't ruin your driving train". The loose surface will allow some amount of slip on the wheels when cornering ( this is the critical point) which on dry and firm road won't do. BTW, Andrew talking specifically on fulltime 4WD.

[@Phil_McAvity]

Totally agree Andrew. Are we getting a Christmas countdown this year?

[@georgiofortuni2802]

I was about to buy a full time 4wd Land Rover defender, but after watching this video I am researching to buy a part time 4wd Land Rover series 3.. Thanks Andrew!

Well, on that Pajero mentioned, even if in 2WD, it still spins the complete front, doesn't it? Because it doesn't have freewheel hubs, right? So I imagine it makes no fuel savings. Then I wonder, what is that mode good for at all? It's the same on my recent L200/Triton. Any advice?

[@byronevans7490]

After replacing the chain in a full time transfer case 3 times. I made my transfer case a part time one with a kit. And never had to replace a chain again

[@rantyrobski9555]

Chain?

[@matthewmckinney2709]

I have the rare full time 4WD with 4 Lo option on my 2005 Chevy Tahoe. It is amazing in the snow. It’s the Borg Warner 4482 transfer case. It has full time 4WD (60:40 split) and the 4 Lo button that allows the center diff to lock it to 50:50 torque split. But it has no 2WD option. Sometimes I wish I had the standard transfer case. But, it’s a very unique setup for sure. It’s a similar transfer case to the Borg Warner in the Hummers (BW4484) but mine lacks the 4 Hi (locked center diff) option and the Super Low option some Hummers have (3 speed transfer case).

[@jpsjg]

This is why traction systems like Jeep Selec-Trac or Mitsubishi Super-Select are some of the best systems in the world, because you have all the options to choose (2WD - 4WD Part time - 4WD Full time - Neutral - 4WD Low Range). I have a Jeep KJ with factory Command-Trac system (Part time) and I always missed being able to use 4WD in wet pavement or even in some off road situations like, when turning sharp where you can feel your trans binding even in the dirt. A couple of years ago I made the convertion to a NV242 Selec-Trac systems (basically changing the transfer case, the lever and reprogramming the body control module) and it's one of the best mods I have made to my car. Incredibly this is a rare modification because people usually tend to think that Jeep NV242 transfer cases are weaker than NV231 ones. It is totally false. Humvees came from factory with NV242 and Jeep now offer it as an option in the Wrangler. Something never seen before.

[@blitzer25blitz62]

was thinking to do the same on my fulltime 4WD, all time 4H 2005 Fortuner for improving FC. now im leaving it as it is. superior road grip noticable at rainy tarmac.

[@khadijagwen]

I had a 1916 Subaru Forester All Wheel Drive and loved it. I could be quite sassy with it. One time I did get stuck when the whole vehicle fell through ice on top of snow and bottomed out on the frame, leaving all the wheels spinning. I think the weakness of my vehicle is that it had a whole plethora of electronic, fiddly bits, and if they malfunctioned... Still it was quite a lovely car.

[@dunk4373]

That’s why I love my 2017 triton. Best of all worlds. Can drive in 2wd you can have it drive like an AWD - then you can lock the centre diff for 4WD with hi and low range.

[@mark2073]

When in 2wd does the front diff spin always, driven by the front wheels? That's what I dont want.

[@Bradthetruckie]

same system as the pajero and alot of other late model ifs vehicles, theres a vacuum solenoid on the diff to actuate unlockable hubs inside the housing. yes the axles them selves still turn yes but not the diff. its also a good way of keeping the cv boots soft.

[@FERNANDOOYARZUN]

An excellent explanation. Thanks!

[@mark2073]

So tell me if I understand this right. The mod allows you to stop the front end from spinning while in 2wd, where it otherwise spins as driven by the front tires? Or does this mod disable full time 4wd and these vehicles dont even come with a 2wd mode? I dont have an 80 or 105 so I dont know. I agree that it is better handling to drive in full time 4wd and that fuel savings are irrelevant. However, I want the ability to stop the front stuff from spinning if I want to. It increases diff and birf wear and if you happen to break a diff or birf, what are you going to do if you cant disengage it? I want the ability to put the thing in either fwd or rwd if damaged, by removing a driveshaft, and not have a damaged diff explode into a million pieces because it's being forced to rotate for 500 km by the wheels.

[@bamacruiser149]

mark2073 it stops the front wheels from turning unless you lock the front hubs. Steering is lighter and less drivetrain power loss. Turns the center diff into a spool. You have a true 4x4. Awd is only 1 front wheel and 1 back wheel turning at any givin time.

[@Triple-N]

Was wondering if your fuel consumption comparison was done with mainly highway driving or city driving? If there are any differences in consumption and tyre wear when test done in mainly city driving?

[@Tanner731]

come on man. you know it wasn't even remotely that scientific or detailed. he did the good ole gas pump mpg calculation a couple times and made up his mind lol

[@ranjithpowell6791]

Brilliant. I am going to go with full time 4WD Toyota hiace now, whereas before I was concerned not to have 2wd option. Thank you!

[@philipjooste9075]

While I agree that one would probably never recoup the cost of a full-time to pert-time conversion through savings in fuel consumption, it is a well-established fact that disconnecting the front axle by means of free wheeling hubs or any other means WILL improve fuel consumption. Case in point: Jeep's new Wrangler JL (2018) is fitted with a front axle disconnect system (FAD) for that very purpose (squeezing out a few more mpg).

[@4xoverland]

YES. 2WD WILL improve fuel consumption, and only on dry tarmac and by 0.001%. A minuscule saving for the cost of safety and increased tire wear. Driving 2WD is a net loss!

[@jimbotheassclown]

It's physics more drag = more power needed = more fuel . I don't care what story you tell Physics don't change because you disagree with them .

[@insipidpostule]

@@jimbotheassclown He's suggesting, quite rightly, that the amount of power needed to overcome that drag is so minuscule as to make no difference. You can rotate these components in their housing by hand, a 4.2l diesel will not even notice the tiny increase in demand.

[@Revnge7Fold]

@@4xoverland correct me if im wrong andrew but is the net tire ware not more with awd? Less tire ware front more in the back with 2wd? My point is less overall tire ware in 2wd?

[@philipjooste9075]

@@4xoverland Respectfully, your findings expressed w.r.t your Zambian friend's Pajero is anecdotal and does not take into account that the vehicle was not fitted with free wheeling hubs - the front driveshaft, differential and side shafts therefore, were still spinning in unison with the associated drag/friction/power sapping rotational mass; resulting in the minuscule saving in fuel consumption you describe. I'd like to suggest a collaboration with Bill the engineer (Defender Mods & Travels) who will happily (I think!) crunch the numbers and provide the data to settle this matter once and for all. If you're watching, Bill - how about it?

[@00ninja00]

I’m curious now, if I could run my Jeep in high 4 all the time, and if there’d be any long term issue? Years back, I owned a Isuzu Rodeo, aka Honda passport. Something screwed up in the front diff and the fork couldn’t come undone to go off 4WD. So when I tried to shift into 2wd it’ll make a loud chatter and won’t go into 2wd. Anyways, it’s an old suv, I didn’t care if it breaks. So I ran it 4Hi all the time. Never had an issue. Can run 70-80mph on freeway no issues. But I don’t want to try it with my new Jeep unless it’s proven it’s ok and can run that way all the time.

[@huckcast7175]

Just bought a HJZ105R GXL all time 4WD, thanks for the great video

[@MediaFilter]

@4xoverland Andrew, second video of yours I've seen and hold your experience in high regard. Tell me: For an older ('70s) 4-5 ton gross vehicle with RWD, I'm looking at installing something like an Eaton G80 rear locker as opposed to attempting a 4WD conversion. What is your view on good, old school automatic & pure mechanical rear lockers like this? What percentage of ability to grip would you say it has as against 4WD? Is it well worth it by comparison to the cost of a 4WD conversion?

[@jeffdoak8444]

every 4x4 i have owned except for my old power wagon have had part time 4x4 and can say that the steering gets heaver in 4x4 on most of them. add locking front diffs and the locking hubs make a huge difference on road

[@robertclark2714]

I have an F250 4x4 and a Lexus LX450 all wheel drive with triple lock differentials. My F250 is a beast and I have NO complaints. I understand its engineering and its limitations. The 80 series is an extreme rock crawling reptile when it is locked. Both of these monsters are fuel hogs. I have a 4Runner 4X4 and another 4Runner 2x4. They all have their limitations depending on what you are demanding from them.

[@emodremov9788]

Hi Andrew I have a 94 jeep ZJ witch was a all wheel drive, but it did't t have a locking central dif . So i i changed the trasfer case and now i can locked it. You are right abought the gas millaege - only 25 - 30 miles per tank. But now i can lock my trasfer case in low and hi gear. Witch was worthed for me. Thank You for You videos

[@johnossendorf9979]

I agree 100% ! My 2010 6 speed manual TRD Off Road Tacoma is a great truck! That being said, I wish it had the fulltime transfer case from the 2007 6 speed manual Fj Cruiser I traded in for the Tacoma. For an off road oriented SUV it handled like it was on rails and would out run the Tacoma and many other vehicles on any surface especially the moment it was wet, muddy or covered with snow.

[@renesturmberg8340]

Hi, I'm just wondering what your opinion is by putting manual locking hubs on a full time 4wd purely as a shear pin. So that if something in the front drive train breaks the hubs do, as hubs are easy to carry as spares and easy to replace. Cheers

[@Tanner731]

if the front axle breaks you unlock the hubs and put it in 2wd! you dont want the hubs to be your weak point, they are what saves you from ruining your front axle

[@renesturmberg8340]

This question was in regards to full-time 4wd vehicles, and if it's a choice between diff (crown wheel and pinion) driveshaft, axel/CV or hub on a solid front car like a 105 you would want it to be the hubs

[@johannvanschalkwyk2141]

Andrew, I agree 1000% with you. We also owned quite a few 4x4’s, what I cannot understand is why someone will do that, and not fixing it when back at a proper workshop….

[@BCooke7788]

Fully agree, that is why I love your channel, always the TRUTH based on facts and experience, analytical and clinical. An opinion you can trust.

[@gregatkinson5929]

Interesting Subject , I have a 91 VX 80 Ltd ,owned it for 10 years . It was a Triple Locker + Factory Winch nice truck . My friend whom I purchased it from got it stock & did an 80mm lift & Part Time 4wd kit & free wheel hubs . It handles bad at speed on motorway etc . My feeling was no Adjustable Panhards miss aligned diffs was the main problem , but seeing your discussion on AWD better handling it's made me think again about the problems . I have just bought another 90 VX Triple Locker & Factory Winch all original so will be interesting to compare .

[@peterclaessens2005]

Agree with all you are saying. Have had several Pajeros and never saw significant difference between 2H and 4H. I always put it in 4H as soon as I came off bitumen or the roads were wet, for safety reasons. By the way I saw you at the Perth 4WD show yesterday and wanted to tell you how much I am enjoying watching the rebuild series but you looked to be on a mission so I didn't hassle you.

[@workingovertime4429]

So Andrew if you are driving a part time 4wd would you leave the front hubs locked so if you did get into some wet weather or dirt roads you could simply drop it in to 4H for safety?

[@4xoverland]

Exactly. I even lock my auto hubs on my 70-series the moment I near the gravel parts and leave them locked so I can engage 4wd whenever I like, without stopping. Even though auto hubs will lock automatically, I still need to stop to engage 4wd.

[@AJ-qn6gd]

I wish my part time 4x4 Hilux was permanent 4x4 especially in the winter when the roads get a bit sketchy.