Why your Off-road Subaru needs a locking center differential and how to install one for free

For anyone serious about off-roading their Subaru, this cheap and easy mod is an absolute must do that will increase both the capability and longevity of your drivetrain. It is ideal for overlanding rough terrain, hill climbing, and general off-road, but may not be suited for more casual or infrequent off-roading - unless you wire it be able to keep the variable power transfer it has from the factory. Please watch the entire video to understand the concept of this mod, because there are many ways it could potentially be done.
Subscribe and hit the notifications icon to see upcoming videos on our VLSD and VTD swaps, and as always, more crazy off-roading.
Contents:
0:31 Demonstration of function
2:33 How Subaru differentials (clutch-type) work
4:26 Why you need to be able to lock your center diff for off-road
6:29 How to wire in a differential lock switch
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Resource links for DIY:
Diff lock switch mod: www.subaruforester.org/vbullet...
Cars with VTD center diff: www.subaruforester.org/vbullet...
Like, share, comment (we are always open to video requests), and THANKS FOR WATCHING!

[@powerofyourbrains]

BIG NEWS - Torq-Masters is coming out with the first affordable SUBARU R160 LOCKER ever (thats the rear diff, not the center). These bad boys are scheduled to hit the market this summer for just $400, but we'll be getting some prototypes in soon to test and review! We're looking forward to seeing how they perform both on-road and off-road. Check out our social medias for more info, and subscribe/follow for install and testing updates as stuff happens.

[@kartboarder22g17]

Your gonna love it for off road. For on road, not so much, but still livable. I have a question if tires are different in tread depth, what kinda damage are we talking about? Would it just be pulse engaging the solenoid and causing clutch wear as time went on or grooving as you show in the video?

[@powerofyourbrains]

That's a great question. I'm not totally certain, but I'd imagine that constant difference in tread wear wouldn't be enough to activate the solenoid, otherwise you'd throw a fault code. I think the tcu probably looks for momentary change more than anything else. However, thrashing the car at all opportunities and driving around a lot on pavement in low gear certainly could cause some wear similar to what we experienced.

[@kartboarder22g17]

@@powerofyourbrains Yet you really need difference in rotation to get it to slam on as it does causing the grooving. Not to mention it also depends on the rear traction. If the rear traction is solid and the fronts are slipping and it locks up the impact damage is more than if the traction in the rear is iffy. This would make sense that an LSD is more damaging to this lock up behavior than an open. More likely chance off road to have better traction in the rear with a locker than an open. Some interesting stuff to consider, I would totally agree you want the lock switch, if offroading is your desire long term. I thought about the difference in tire tread scenario some more and I would think it would wear down the clutches more than probably the grooving as the impact would be often but lesser degree. At least it doesn't look like it is the hardest repair to replace....

[@powerofyourbrains]

Yeah, I can only hypothesize really. I do know that for the vlsd coupler on manuals equal tread depth is important, because it's mechanical, and forcing it out of character for long periods of time would really harm the vlsd fluid I'd imagine

[@kartboarder22g17]

@@powerofyourbrains Makes total sense.

[@muth3393]

Just ordered the resistors and a switch to do this myself. Seems like a super useful mod.

[@chasedyer9819]

Such a good video! I thought this would be much more complicated and im amazed at the difference it made. Great explanation

[@powerofyourbrains]

Thanks, we appreciate the feedback. It's good to hear that you've gone ahead and set it up yourself. There are various ways you could do it, but yeah, the basic concept is really quite simple.

[@mikewasowski1411]

This is such an awesome video. Super helpful and excellent explanation. Pitty I never heard of this before I sold my Outback!

[@powerofyourbrains]

Thanks! Appreciate the feedback, and ya never know, might come in handy some day :)

[@thomasstaples]

Swapping in the vtd center dif with a static front/rear distribution ratio of 45/55 and extension case in place of the pro-dominantly front wheel drive mpt center dif is a great “upgrade”. The vtd dif can be sourced from a number of 4eat’s with Vdc/vtd. You do have to install the “awd diagnostic fuse” in fuse box under hood due to difference between the two difs. The fuse simply disables front wheel speed sensor. The vtd center dif is an open dif but still has a transfer clutch to “50/50” lock the awd, So adding the dif lock with the vtd works great for me.

[@aperturemichelle]

this mod really reminds me of the OEM Subaru Forester 110V Power Outlet Kit. you buy a little box but really what you pay for is the diagrams that a show install and instill confidence that its not going to brake a critical part. (you could sell a pdf instructions) But this is one of the cooler mods that im going to have to now look in to So, thank you and Great work! (Because this message is prerecorded, any observations related to your performance are speculation on our part. )

[@MrNcmatt]

Thank you!!! You delivered

[@powerofyourbrains]

We aim to please! Glad you enjoyed

[@Tinker1837]

Nice! Thanks a ton for all the info & great explanation of it! Always thought there was a diff more like an Audi or my Land Rover's transfer case, not that it's a negative, just more simple than I expected! I'm going to have to get after this mod quick-like.

[@powerofyourbrains]

Thanks, glad you found it useful. Not all Subarus work like this like we said, but on models with the transfer clutch having the switch is a huge advantage

[@calebneubert230]

Super knowledgeable and entertaining video, Subscribed!

[@powerofyourbrains]

Glad you enjoyed, welcome aboard!

[@oby3000]

Great explanation!!

[@SaveTheManuals]

This was *awesome* Wish I could implement something similar on my 04 XT 5 speed manual for those messy twice a year situations I always seem to get myself into. Awesome video, cheers from Wisconsin! 👍👍 🙋‍♂️

[@powerofyourbrains]

Thanks! Yeah, importing a dual range is a lot more expensive, but at least you've got a manual xt! Rare beast

[@TheLastCast.]

@@powerofyourbrains Im from the uk i have a dual range 2004 forester 2.0x 5spd manual non turbo im not sure if i can do this mod or not cant find online if it has a vtd

[@powerofyourbrains]

@@TheLastCast. You don't. It's basically the STi setup with a viscous center coupling plus an MPT. To my knowledge nothing non-turbo ever received that setup.

[@TomSilver_42]

@@powerofyourbrains Not sure, I have Outback MY2003 5MT with low range and it does have viscous center diff, but haven't found out if it's somehow manageable, as VTD controllers were made into AT gearboxes only I think. But I'm definitely far bellow your knowledge and skills.

[@AdrianvandenBroeckMusic]

@@TomSilver_42 got a 2004 2.0 manual dual range aswell. Just peeking into the thread in case anyone finds more info on this.

[@dukeofnyd1]

Cool channel! Good info, good presentation! Thanks for sharing

[@powerofyourbrains]

Thanks! Glad to hear you appreciate what we're doing

[@rob164ab]

Hi there. Thanks for posting this! You’ve got my gears turning for my next mod 😜 I drive a lifted 07 Impreza w/ auto tranny. I’ve heard that in 1st and 2nd gear it does lock. It may shift to third if it senses high rpms though I’ve heard too... I’d like to do this eventually but if I can get away with a locked diff in 1st or 2nd then I might work on other things before I get to this. Have you heard of what I’m talking about? Can’t seem to find it anywhere. Thanks again for posting this tho, f*ing great 👍

[@bradleywinter1947]

Please any information further on this would be greatly appreciated I've watched your video over and over again and I also like And subscribe to your Channel thank you for turning these old Subarus into something absolutely amazing dude

[@powerofyourbrains]

Thanks man, we're all about that stuff. More to come

[@76mkdubbn]

Me too,nice meeting you here😎

[@boredbeingbored676]

had no idea it was as easy as using a pwm. thanks!

[@powerofyourbrains]

Thanks, glad you found it helpful. Sometimes it's hard to find good info on these things as I'm sure you've noticed

[@scottcarl3086]

Wonderful video 👍 I learned a lot from this video. One question though. Will this work in a 1993 Subaru Impreza L sedan 1.8 auto AWD? Completely stock.

[@MrDvirpariente]

Hi thanks for the video, it looks great. do you know if it can be done on a 4 gen? the one after the one you use

[@abrossyb5391]

Te felicito, es impresionante lo que lograste, yo tengo una forester año 99 T/M, con palanca HI/LO, se podra hacer en mi forester ese invento?? gracias, saludos desde Chile...

[@thespiritofthenight8196]

Great video. I was just wondering where you got your dpdt relay from because I can't find any

[@ceterisparabus]

It turns out if you had the SG forester with the 4EAT, if you put the car in snow mode it locks the centre and you set gears to manual that works well also. i got my VLSD rebuilt on my SG and got a Monza Torsen D2s front diff made it a beast offroad!, great channel and very detailled vid.

[@bxbLJ]

I have a sg forester 2.0x auto. Is the snow mode that you're referring to the HOLD switch?

[@ceterisparabus]

@@bxbLJ yep. It locks the centre 50 50 and starts in 2nd

[@bxbLJ]

@@ceterisparabus interesting. I knew it started the gears in second. Didn't know it locked it. So if I were to select 1st gear and flip the switch to HOLD, it should function as this video?

[@AnthonyVasquezEndZz]

Awesome video, thanks for this,. I looked at that list but there is no mention of 2008 (5EAT) Foresters

[@powerofyourbrains]

Anthony Vasquez - EndZz Thanks, glad you liked it. You're right that we didn't mention the 5EAT...we're going to try to be less sloppy in the future; thinking about stuff like writing questions down, spell checking, lol. Did mention briefly that it works on all autos, the 5EAT included

[@AnthonyVasquezEndZz]

Awesome thanks for the reply going to attempt to get this going this weekend. Just to confirm although this provides a 50/50 lock front to back it still doesn't solve diagonal wheel spin right?

[@powerofyourbrains]

Also, I do not believe the forum link is all-encompassing, but just the best aggregation to our knowledge. I do remember reading that 5EAT's have the same type of transfer clutch

[@greym6436]

Good info!

[@eternityseven6200]

If im not mistaken simply putting n/c relay in line w solenoid and adding switch would simplify setup and when not activated unit would remain controlled by tcu. No resistors needed, then it would maintain vtd

[@MyEP81]

I like those practical based videos! I'm considering to get a rear torq locker for my SH 6speed diesel but i'm not sure if the center lock hack works for mtm aswell and if not make it any sense to get a rear locker without permanent "locked" drive to the rear. Maybe you can help me out

[@sumexp7228]

Hi there awesome work btw I have a lot of questions but staying focused to this video this has nothing to do with the factory "on/off" tcs button right? And if not does it work for 08 manual transmission ? Last but not least 😅 how would it work with the tcs on or off? Feels like a newbie question but hope you can learn me 😌

[@berserkerusmc7613]

Wow! Awesome modification! Would this mod work on a 2015 Forester CVT with MPT (no X mode) ?

[@crohkorthreetoes3821]

respect

[@thehighcountrymedicalclini794]

Hey man love the vids, super informative definitely a go to source for hands on knowledge. Do you know of anywhere that has a wiring diagram for this mod? And do you know if it will work in my 2003 forester xs as I do not see it listed in the forum you've linked above and its supposedly an incomplete list? One more question what engine management system or monitoring system are you using as I cannot locate anything for 2003-05. Thank you

[@powerofyourbrains]

Thanks, glad you enjoy them. This mod should work for you as long as you have an auto. I don't know of any mod diagrams, but if you check out my ej25d camshaft install video, there's a link to Subaru repair manuals which should have yours. Just use the diagrams to find the tcm. We explain how to do a simple switch at the end of this video, which is what we have. It's controlled manually because our OEM ecu can't control the vtd we swapped in there. There are a number of ways to do this mod, but they all involve the act of controlling the power that provides the signal for the tcm in one way or another. If you have something in particular you're trying to accomplish I will see if I can help with more details, but you might ask a wiring-savvy friend if they could help you with the install just to be safe

[@MrNcmatt]

The High Country Medical Clinic Mmc did you ever make this modification. I also have a sg forester I wanna do this to.

[@xiaoyu88]

Thats pretty neat. will it work with the 5 speed auto the 2007 outback has?

[@sky_ful8426]

Nice video, very helpful to know. Does anyone know if you can do it on a Subaru forester sf from 1997 ?

[@deadbedhead]

Super cool , I had no idea but now it's something else I wanna try. Also how did you secure the snorkel to the window frame ?I'm looking to do something similar but haven't quite figured out all the details

[@jasonchall3766]

daniel paris There are 3 pins protruding from the sheet metal that hold the trim to the edge of the window. I made a small bracket with a hole that goes over that pin which is retained by an e-clip snapped over the pin. That pin eventually got torn out of the sheet metal when we snagged the snorkel though. so now that same bracket is pop riveted to the sheet metal in the hole left when that pin was ripped off. Works ok, but the pin is pretty small. Probably going to try something different in the next one.

[@deadbedhead]

+Jason Chall thank you man , I kinda get what you did . Either way I appreciate your help

[@crazyDIYguy]

That's awesome, I wonder if you could use that gadget to remove your front shafts on an auto and have full time RWD, I heard the auto-majics just transfer all the torque to the front if you remove them.

[@williamhayes9642]

This is great! Can you do something similar to the rear?

[@powerofyourbrains]

Thanks, we have a video on how to swap a vLSD on the rear, which is a pragmatic and inexpensive thing you could do. Works well for the money. Otherwise, a clutch-type lsd would be 1k+, and an r180 locker setup would 2-3k more than that...no electronics to tool with back there. Better off investing in a long travel setup to prevent traction loss from occuring imo

[@4x4.tests.on.rollers]

Hello, great video! I have a question about the solenoid/valve - it is normally open (no power = clutch is locked) - I remember that there was a change into normally closed (no power = clutch is open). Do you remember when was the change (2005?) and was it to all models are some specific ones?

[@powerofyourbrains]

Thanks, I'm not sure, but if I had to venture a guest I would say that the change probably occurred around the transition to the phase II 4EAT circa 1999-2001.

[@Dpiz911]

Bro how can I get a schematic of the relay hook up a few weeks ago I blew up my center diff due to tire spin. This videos was absolutely just what I needed you guys rock!

[@CarSyndicate]

Green and white wire out of your TCU is (at least for me) the wire to the solenoid. You just wire a DPDT switch that disconnects power from the solenoid, but at the same time sends power from the TCU through a 'dummy load' like in this video. this stops you from getting any trans error codes from the solenoid suddenly disappearing. There are some decent write ups on this but unfortunately most of the images don't work. Curse you photobucket.

[@florinsoltan8058]

Absolutely great job and nice video. But quick correction but the real Subaru VTD was coming only on the transmission TV1*something. Your one's is TZ1*something... There is huge off-road capability in those TV1 transmissions... basically they have rear end with gears instead of plates ( like the one in your video). Firstly, worth to mention, the TV1 transmissions they are sending whole their torque to the rear wheels in proportion of 65% to the rear and 35% to front and it depends on conditions. So TV1 is the best to go! 👍

[@alain99v6]

Yupe swapped my blown MPT in my old 2001 H6 USDM for a JDM VTD unit , it was cheaper than a used a transmission from a regular yard, the car was high fun to drive in the summer but it the winter wihout any proper lock control in heavy snow the car was too prone to drifting

[@ThatGuy-xd5fs]

Question if i have a ty754 or a subaru 5 speed then how do i do this? I think they dont see the 20lb sti is made anymore and i dont want dccd

[@mmorwood92]

Hey mate absolutely love your work. Are you aware of any issues with the new sj xt foresters with the fa20 and cvt. Appreciate it.

[@powerofyourbrains]

Matthew Morwood Media Thanks for watching. I'm not really familiar with the cvt, but I believe it distributes power in much the same way. You may find this to be helpful media.subaru.com/pressrelease/580/123/subaru-offers-four-versions-symmetrical-all-wheel-drive. If you are using the XT for true off-road purposes, the transfer-clutch is advantageous because it can be locked with this mod, unlike models with viscous coupling. If you are using it for on-road or mostly flat terrain, it may not be necessary - it's moreso the jolts from sudden application of power that cause damage to the transfer clutch.

[@mmorwood92]

Thanks man. Yeah I do a bit of heavy offroading trying to keep up with patrols and cruiser in Australia. I have the xmode electronic stuff but it isn't perfect and I love your idea of actually manually locking that center diff. I might have a chat to Subaru aus see what they know.

[@powerofyourbrains]

You might also try digging online through the forums - there are some good ones out there that go over the variety of ways the switch could be set up. Linked one in the description, but its not current enough for your purposes

[@shawnbrewer8900]

So I've got an 03 Baja non turbo I'm wanting to do this to. Is the 03 4eat normally with or without power? And is there a video going a little more in depth on how the DPDT switch is wired to reverse the logic so the light has power when the switch is doing its job. I'm a more visual learner sorry 😅

[@MrDanbalos]

Just watched this, very interesting and innovative! Can this be done to a 2018 Crosstrek?

[@powerofyourbrains]

RoadPirate 50 Thanks, and that's a good question. The cvt is uncharted territory as far as I'm aware. Can't imagine it'd be quite as strait forward, but where there's a will... We have no access to any late model examples to experiment with unfortunately

[@axllebeer]

This has peaked my interest as I have a 2014 XV s well. Or CrossTrek, take your pick with the name...

[@scottwilson8497]

I would think that doing this on a CVT would render x-mode useless though.... unless X-mode doesn't control the center diff.

[@powerofyourbrains]

Lookw like Xmode increases center lock by only 25%. In theory, full lockup would make Xmode better

[@racerx6384]

@@powerofyourbrains cvt doest seem to even allow wheel spin. Im assuming to make it easier when it locks up. Xmode will increase the likelyhood that it locks the center diff and since it only operates below 18mph probably doesnt stress the center differential.

[@juanitovalderama]

Where is the complete wiring diagram so i can follow it!

[@MrDanbalos]

Thanks for the quick response! Will the Cusco work in the front?

[@powerofyourbrains]

I don't know off hand. Not sure why you'd want one there though

[@pulanis]

It `s genius. It is a pity that I have manual gearboxes because a very useful thing. Greetings and I wish you further successes.

[@powerofyourbrains]

I still prefer manuals though, and will until I find myself more offroad than onroad. Thanks!

[@jasonchall3766]

You can get a manual with VTD, which supports this mod.

[@AWDfreak]

Szuwaru Tv - the equivalent of such a thing would be to use the STI rally-spec center differential (not to be confused with the DCCD used in the WRX STI), which has a higher center differential lock-up torque which works excellent on loose surfaces, but high traction performance in corners such as doing tight turns on dry pavement, suffers due to the excessive lock-up characteristics. These center differential units are used on Subaru rally cars on most low-traction stages where the DCCD is not allowed.

[@gabrielbarreda22]

Hey man can you guide me how to do this on my 2000 Subaru forester ?

[@ForgotToMentionThat]

Curious how this works with the CVTs

[@Abbbb225]

Separate question: seems 5th gen outback brake traction control is much better than 4th gen outback. I am comparing 3.6 4th gen outback to any 5th gen outback. Not sure if difference is more a function of MPT vs VTD (i.e. CVT vs 5EAT) or 4th gen vs 5th gen, even comparing 4th gen 2.5CVT/MPT to 5th gen 2.5CVT/MPT. Also take x-mode out of equation, since 4th gen does not have. Thinking of buying 4th gen 5EAT b/c I like feel of VTD, but for off-roading it seems like a trade-off - more wheel slip and less aggressive/effective brake traction control, so probably puts more power down for snow drifting, mudding, and hill climb, where you want momentum and wheel spin, but can be more easily defeated by off-camber situation (or any situation that causes traction loss to at least one wheel on both axles), so worse for slow, controlled wheeling. Is this accurate? Anyone have lots of experience with both systems? I'm basing this on comparing lots of vids and limiting driving time I've had in both cars - haven't had a chance to test with rollers or do extensive off-road testing to be sure. With all the subaru nuts on the internet and suby meets that I'm sure go on, frankly I'm stunned no one has done roller tests with all gens/systems on outback and other models side by side to clearly show differences (would be really easy - just bring rollers, or some small ramps, and film it).

[@powerofyourbrains]

We have a video from about a year ago comparing vtd vs non-vtd. Long story short, vtd with a lock switch installed is definitely the best setup.

[@thec130side]

Game changer

[@MrScalman]

what about that 1st gear on 4eat ? i heard on those gearboxes 1st gear locks center as well. or its not ? and some people making that button like in 3 configs even. not just on or off. like if you give there other voltage then 12v you get slightly diff results. interesting info there, so you have VTD there ? so its like those VDC outback models ?

[@powerofyourbrains]

scal man We swapped a center from a Legacy gt, works the same way though. We plan to test the extent of locking in 1st, but pretty sure its only a partial lock

[@maker000]

Okay so I have a WRX that I recently put a STI trans in (has DCCD). I swapped because my old WRX trans was squeeling from the rear of it. I do a lot of offroading (cell site technician) and now I know why it failed. Thanks for the lesson!!! (Btw I ended up using a MAPDCCD.)

[@frfigueroa2002]

ABSOLUTELY AWESOME! do you have a shop where you can do mine? 08 Tribeca. I like subarus but im not at all mechanically inclined. Please be in CA....please please please.

[@powerofyourbrains]

Haha, we are pretty far away from you here in WV. No shop either, though many have asked. I think an electronically inclined friend would be your best bet dude

[@maxrobbins8872]

Will this work on a 2014 Subaru Forester 2.5 i cvt

[@RKmndo]

Which sundial tool is used for installing a locker in a 2016 CVT Crosstrek?

[@COWGIRLMOTORSPORTS]

will this work on a 1999 Subaru Legacy L AWD??

[@powerofyourbrains]

Check out the full mod overview video linked in the description for more!

[@RyanJ-RE-BUYERS-PT]

Power of your brains do you think I could I do this mod on my 2014 crosstrek 5sp?

[@flyxero2415]

Hi,can it be done to 2018 subaru xv?

[@jhoward103]

Hey POYB, I've read on Subie forums that putting the 4EAT in 1st or 2nd gear locks up the center diff, with no need for a mod. Is that BS in your experience? Thanks man!

[@powerofyourbrains]

@@jhoward103 That's not BS and that is how it works. However, if it locked up fully then it wouldn't take long to damage the transfer clutch, so its likely some degree of partial lockup. We've been meaning to hook up an oscilloscope to quantify this theory but haven't gotten around to it. Also, back before we had lockers we used to drive around in low gear for this purpose, but frankly, we didn't like redlining the car all the time.

[@jhoward103]

@@powerofyourbrains LOL, makes sense. And thanks, that's great info. I've had good luck so far with my stock '06 in 1st or 2nd gear, but I think true center lockup and maybe a torsen rear diff are down the road. I'll likely run it as is until I break something tho, lol. Thanks again!

[@chispagiddings]

How do i know if I can do it to my car? A 2017 6speed manual subaru xv

[@merlin2072]

I have a 2008 outback with 4EAT and checking my wiring harness i do not see a white and green wire. Do you know where to get the wiring diagram for my car.

[@fialho_english_tips]

Hi mate! Great video. I own a stick Forester. Is it possible to install any device to block its diff?

[@powerofyourbrains]

Unfortunately no, unless you also have a dccd (like the sti). You have a viscous lsd which should theoretically provide a 50:50 split, provided you can keep all wheels on the ground. Long travel suspension work and low range would be the way to go for you I believe

[@fialho_english_tips]

@@powerofyourbrains Got it. Thanks!

[@matteoperron5436]

Cool video, I was hoping someone could answer a question. I have a 2011 forester with a 4EAT and I've been reading online that the power distribution splits to 50/50 no matter what when in manual mode. Is that similar to this mod or is there a difference?

[@powerofyourbrains]

The lockup is increased in 1 and 2 but our testing showed significantly less torque bind, so it's probably only about 70-80% locked.

[@adamspiels]

With that veepak obd2 reader ive gotten tcu errors cus it jams up the com on the ecu

[@acesarp]

Is this mod doable on a 2007 Outback 2.5 non-turbo (basic) 4EAT?

[@jensiw419]

Can you guys tell me if there is any difference (beside the center diff) between the 4eat of natural aspired subarus and turbos? I'm running a WRX ej205 engine in my 1970 VW bay bus and want to install a subaru 4eat transmission (tz1a4), which came out an natural aspired car. I'll be converting it to 2WD, so the center diff won't be used any more.

[@alisagdastgeda5679]

hi my friend ,can do it with subaru tribeca b9?

[@PatrickRich]

Super interesting information. So technically a standard 4EAT wouldn't have a center differential at all, just the clutch pack that engages based on sensor input. In the case of a standard 4EAT, wouldn't the TCM control the lockup solenoid as standard when the power cut isn't achieved by the lockup switch? i.e. switch off - TCM controls modulation of the center clutch. Switch on - signal to the TCM is interrupted and solenoid is forced on. In either case you are still relying on the max clamping load of those plates and the hydraulic pressure that can be applied to them, right? So not a "locker" in the traditional sense of mechanically binding the input and output shafts (or left and right outputs) but more a "full power to the clutches!" locker like a Jeep Quadra Drive II differential or Fords new ELSD" Or very similar to how most on demand type PTO awd systems work today where the rear drive torque is achieved solely through a clutch pack and the "center lock" button in some factory AWD vehicles simply instructs the control logic to apply max pressure to those clutches. i.e. 3rd gen rav4 with a "C.Diff lock" button but no actual center diff vs my old 1st gen rav4 manual with the same button but an actual collar that locked up the actual center diff. man, with the torsen rear and the center locked that thing was actually pretty mighty off-road.

[@powerofyourbrains]

Correct; what is referred to as a diff is really a clutch pack. This mod will increase capability a bit, especially on older models with a 90:10 F:R default torque split. However, I would say that the biggest reason to install a switch is the increase in durability it conveys to the clutch basket. The plates lock together with a substantial amount of force, but they don't easily wear due to the robust wet-clutch design. However, the basket is vulnerable to damage incurred during actuation under frequent and severe conditions of...well, abuse, frankly. Manuals have a true vLSD differential that cannot be locked (except the STI which has MPT and vLSD), so there are advantages to the automatic for off-road - provided you do this mod.

[@alain99v6]

2 things a 4EAT with the VTD instead of MPT transfer section will have a center dif and you could convert a MPT to VTD either with a full swap or just a rear case swap and also depending of the year of your Subaru (2004 and up vers 2003 and earlier) there is 2 ways to do the mod, sending power or sending a ground signal , I don't remeber which used which it's been too long

[@frogswurld]

I did this on my old 01 Forester years ago. Works like magic just DON'T drive it on the road with it on. Bad stuff can happen...lol

[@janmichael-vincent7585]

Like what? 🤣

[@amberhunter1115]

Pleas like what ???

[@Barrenchats]

If the MPT center diff was replaced with a VTD center diff wouldn't you just need to put a 10 amp fuse in the FWD slot in the engine bay fuse box to "trick" the TCU from throwing a code, then all you would have to do is remove the bulb from the dash cluster 😎

[@Z0RBEG]

I need this on my legacy

[@bradleywinter1947]

I was wondering if you might be able to draw me up a diagram to show me how you wire the TCU into the Dual switch relay and what size specifically Ohm resistor you used to trick the TCU to think that it's the solenoid I think I understand what you did but I'd like to have a more firm understanding I would really like to do this modification on my 02 Outback

[@powerofyourbrains]

I didn't do a diagram because there are differences between models (some older models lock at 12v, for instance), and many ways this mod can be done. The purpose of this video is to explain a concept which can be applied to many vehickes. Looking through the forum post linked in the description, you'll see that the resistance may vary model to model and car to car. You'll need to measure yours using a multimeter and get a resistor in whatever ohm measurement you get. I'm glad you enjoy the videos, and hope to come out with more mod tutorials soon, including the upcoming center diff lock install on project off-road granny because we're gonna do it a little differently this time.

[@MrE1963t]

Is there a way to do this on a 5 speed manual non CVT?

[@dalecooper9040]

Hi, I have a Subaru Forester 2009 and would love you lock up the centre differential please could you help me. Regards Dale

[@GeoRS7]

Hello , can that mod be installed into a Forester SH 2.0 5MT Transmission Type : TY758XTZAA

[@akumabito2008]

What are the options to improve off road capability of the dual-range manual transmission Imprezas?

[@powerofyourbrains]

Do you know which reduction you have? As far as manuals go they're the best tranny. It'd be sick if you could also add a torque converter but that's not really how they work. Best option is would be suspension work in my opinion. Remove any sway bars you might have and set up long travel to conserve your momentum - I think you'd be amazed at the difference.

[@777MAV]

I believe VTD is system applicable to auto gearboxes with center diff, (TVxxx). You can lock them as well (as you did), but solenoid control has kind of opposite logic - it needs no signal to unlock and signal to lock. I swapped my TZxxx gearbox for TVxxx on SG5 and couldn't find proper TCU. My old one works fine for everything except center diff control, I had to cut this wire for now until I find proper solution.. Not a fan of resistor trick because it'll probably become quite hot. Manual gearboxes (at least in Imprezas) all have center differential (your old auto TZ* gearbox doesn't), and manual would either have viscous diff or DCCD (STi only). You can lock DCCD, but I can't see how you can do anything to lock viscous center diff without changing it completely.

[@powerofyourbrains]

Yeah, which is why Subarus claim that they lock in new mt models is bunk. It sometimes is reversed, but on our 2002 and 1998 models the MPT is the same as the VTD-MPT. The fact there their are models out there that are is one of the reasons we didn't make this an instructional video. Also, our setup with the resistor on our 2002 has been 100% reliable, so take that for what you will. Granny (the 1998 one) is setup differently, and still utilizes stock functioning of the MPT when off

[@777MAV]

@@powerofyourbrains Great, maybe will put resistor on my car to stop that light blinking, but that's just daily driver, so it was ok as is. Other than that, I'd rather have continuous control of VTD in OEM fashion, not only lock. But these TCUs gor SG5 with VTD gearboxes are kind of rare.. Have you ever considered using some custom transmission controller? Like MegaShift maybe or something similar?

[@DavetheRaveDinkum]

I would've wired in a relay to reverse the AWD clutch solenoid signal, problem solved 👌

[@massni94]

Yo You seem like u know your stuff Any chance you'd be knowledgable on a VTD swap for a 2010 4eat with MPT and VDC? Or even the diff lock mod for the SH (2010) 4eat? Heard the cars wiring is different- need to remove current instead of supplying current

[@powerofyourbrains]

TakingShitApart I cant say anything certain for your car, but for the 4eat in the sf Forester, the VTD from a legacy GT bolted right in place of the stock transfer clutch. Now, bear in mind that in order to figure this out we just had to try it, and luckily it was a direct fit. Wouldnt be surprised if it was the same for your trans, but don't know for certain

[@massni94]

Did you need to use the vtd bell housing or just the vtd unit itself?

[@powerofyourbrains]

The whole assembly just bolted right up. Dunno if id attempt to just swap the internals

[@massni94]

Nah, I don't think just internals would work at all hahah hence my question :) Cheers for the speedy responses

[@drew5337]

Is there a way to do this to some of the newer models? Wife has an 18 Outback, and I'm looking at a new Crosstrek. Mine will definitely get off roaded.

[@powerofyourbrains]

As long as it's an automatic it should be possible, as Subaru still uses the same mechanism. I can't personally say how the locker will interact with traction control systems such as x-mode, but it could in theory help to supplement them. If you try let us know. And I'm not sure this is true for cvt models, but you get constant lockup when shifted into 1 in the 4EAT. It's not full lockup, but mostly. You can use the drive around in a circle test to confirm.

[@XVIIsionsProductions]

Okay so I have been digging absolutely everywhere trying to figure out if this modification is only done in a 4EAT with the MPT or if it can be done on both MOT/VTD and I have been trying to figure out whether my 98 legacy outback limited 30th anniversary edition car has the damn MPT or the VTD and I still can’t find that info... I think after searching everywhere and reading a billion threads and brainstorming how in the hell this all works etc etc I need an answer to this and I hope I can get a reply. This switch mod to control the solenoid is ONLY done on a 4EAT with MPT “center diff” and NOT on the 4EAT with a VTD “center diff” am I right or am I wrong? Can it be done to both or should it only be done to one or the other?!?! Gaaahhhh my brain is on fire 🔥

[@nrwillette]

I believe it is only for the MPT 4eat, because the VTD is next level already and the lock up mod brings the MPT close to the VTD level.

[@stupidbuilds2759]

I'm new to Subaru world, I bought mine in December 2019 I have a 1997 legacy with the 2.2 and an automatic. Do I have any options for a center differential selectable locker? Thanks

[@ranga2050]

The same process applies. All Subaru 4EATs use the same logic to drive the transfer solenoid. Resistance wise you need 16-20 ohms. I use 2x 100Ohm and 2x50Ohm 10w resistors all wired in parallel. Works a charm!~

[@dirttales]

How much does this mod help with diagonal wheel spin? That's the only issue I have with my 08 Foz... and I feel like only a rear locker would help..

[@powerofyourbrains]

Other than added durability, the benefits of this mod occur before you're in the predicament of having diagonal wheel spin trying to overcome some obstacle. Depending on your driving style, it may be hard to perceive the momentary delay in rear wheel power as you depress the throttle. This mod lets you fully engage both differentials under partial or full throttle before any traction loss. In other words, it won't help stop diagonal spin, but will help to prevent it from occuring. As far as the rear diff, we swapped in a vLSD (See video). It's not as good as a full lock, but for the money you can't beat it, and it's durable.

[@dirttales]

I've always read vlsd units are rather useless after 60k. It would be nice to do an r180 swap but I cant seem to find one in 4.44..

[@powerofyourbrains]

Been all the way down that road. It ends with a guy in Austrailia who can custom fab you an r180 for 4k USD. The vLSD does pretty good for what it is. Check out our vLSD swap video - the unit demo'd in that Hill climb had 200k miles on it

[@0xsergy]

@@dirttales if its clutches, maybe. if its fluid based it should work so long as the fluid is good, right?

[@MrDanbalos]

What differential is on the current 2018-19 XV? Will this work on it? The Torq Master?

[@powerofyourbrains]

R160 and yes it will

[@rebel1988us]

Can you use a 3 way switch having a 12v source, the normal config for street driving and 0v for off?

[@powerofyourbrains]

A 3 way would work for basic manual control. The diff is engaged at 0v, so ideally for street driving you'd run 12v since you don't want to be locked up all the time on pavement

[@d0stawca]

@@powerofyourbrains Ok so basicaly all you do is cut feed to selenoid and when you switch it off to run power through it is back to automatic mode? Apart from your foz where you have vtd which it can't manage and you got it in fwd or awd without auto mode? Or I understand it wrong? :) It works with every 4EAT box?

[@powerofyourbrains]

Essentially yes. Works on 4EAT and 5EAT, as they all basically work the same way. You'll need to add a resistor where you splice the switch in as well, but you can find far more info on the forums about that.

[@zacksheidler]

@@powerofyourbrains sorry if I missed it but what value resistor?

[@CBRGen]

Could this work on my 2002 Subaru Lancaster H6 ... trying to lock my center and get my rear diff with auto locker system.. please help the subi gang lol

[@evanpoitra5474]

any chance y'all would sell a kit for the 4AT Baja turbo?? Id buy it today!

[@powerofyourbrains]

We don't...sadly our careers have exactly nothing to do with cars or off-roading, but I do wish we had time for that sort of stuff. We'd love to just hang out in a garage making stuff all day...that'd be awesome. Perhaps one day...

[@evanpoitra5474]

@@powerofyourbrains alright, thanks for the lightning fast reply!

[@lannycrockett6571]

can you do this with a manual transmission?

[@jarrodpagac]

More parts needed for the Nerdwagen build

[@powerofyourbrains]

Nerdwagon...simply an amazing term

[@4x4MadnessNZ]

Heu guys just wondering if this sort of thing can be done on a manual gearbox in the subaru? Im new to all this ive just lifted my impreza but pretty keen on 50/50 4wd so its good to go. Also if there is a manual tranz what code is it and what are they found in that i can hook up a switch on? Thank you

[@powerofyourbrains]

Nope. This has been answered and explained many times in other comments on this video. Check those out if you want to know more. Good luck dude

[@IPS0125]

Can you do this mod and install a rear diff Torq locker?

[@powerofyourbrains]

Yes you can!

[@Zcypot]

is this an issue with the older models? Took my WRx to the snow on summer tires and all 4 wheels spun all the time without issue, 50/50 split.

[@powerofyourbrains]

If your rex is the same as your icon pic, then I have the same car as you (see our channel banner pic). New and old Subaru's work this way, but only models with automatics and manuals with VTD's (STi's. spec B's maybe). Our cars have a viscous center coupler diff that cannot be controlled - ergo, 50/50 split is achieved with the application of throttle. The good thing about this setup is that you don't have to worry about breaking your center, the bad is that depending you need to pretty much nail the throttle to achieve the same effect as the locker in similar conditions. Additionally, our rear and front differentials are open, whereas older WRX's had a rear VLSD

[@JMaksym]

Can somebode confirme that in Forester SG when you block on 1st od 2nd gear and set up button on HOLD than you have the same result 50/50?

[@massimomartina2889]

that would be interesting to know also for me

[@brauliomedinalarregla4813]

Hola como esta? Podrías ayudarme? Mi diferencial central está bloqueado permanentemente y está haciendo daño! Que puedo hacer?

[@nooraminhashim]

Can i do this to rx300 awd 1999

[@TylerScranton]

Seriously though this was a Regular Cars video at times.

[@powerofyourbrains]

Well. Looks like we need to try even less then

[@stevel1218]

Can diff lock switch be installed on a 2014 Subaru Outback, forester

[@Barrenchats]

yes all 4eat MPT transmissions

[@LarryRichelli]

I am considering a 2005 3.6 outback with the 5EAT. Can I do this mode on that car? If I can't I am not buying it!

[@jerryknight9566]

So do you need to pull the center diff to add this switch? Or just trace the wire and wire a switch on the line?

[@powerofyourbrains]

You don't need to pull the diff. That was just for illustration since we had the old one lying around. Its a purely electrical mod. Check out the forum link in the description, and you should be able to find many more resources online

[@eze8024]

Which is "better" when locked, mpt or vtd? I understand that vtd is pretty much superior to mpt when unlocked and controlled by the tcu. But once locked, is one stronger than the other?

[@powerofyourbrains]

VTD (still has an MPT but it's used to manage torque distribution vs transferring the torque directly)

[@eze8024]

@@powerofyourbrains yeah, I've heard the mpt clutch packs can "grab harder" than the clutch packs in the vtd, but then everybody says the vtd is better. I would like to swap to vtd, unless mpt actually can "grab harder" than vtd when using a center diff lock switch

[@rc2300s2r]

@8:34 also an alternative way to use brake fluid to stop. 😋

[@powerofyourbrains]

This is very true. Fricken love RC cars

[@Arsopu]

What am I missing in these comments

[@colesongriffith1267]

What models of subies does this mod work on

[@massni94]

Also- do you have any clue if the TCU and VDC systems on the newer ones are integrated / linked? I'm worried if I swap out the rear bell housing of my tranny for a VTD one (with all planetaries n shit of course) it'll screw up my vdc. Also heard there's an issue with the front and rear output shaft tone rings being different- hence it will throw a tranny code. Some people solved by inserting front wheel drive fuse and using a switch to supply lock up voltage when needed. Can a custom tone ring be made? Im worried if I run my standard tcu with a switch mod controlling the VTD clutches that it'll throw a code- and whilst I might be able to get it cleared, it'll disable VDC completely (or even abs too- like when you pull the VDC fuze to completely disable it). Sorry for all the questions Thanks in advanced

[@powerofyourbrains]

Sorry your comment got caught up in the idiot filter. Short answer is I don't know for sure, and the long answer is more than a guess. From what I understand, VDC is basically torque vectoring by use of breaks. Manipulating the breaks most likely manipulates the VTD as opposed to actually controlling it, such that it can initiate torque transfer under a broader range of conditions, other than complete traction loss. I don't know if locking the diff would actually trick the VDC into being inactive, or if it would continue to selectively brake which of course would be extra wear on your breaks and what not. Sorry, you'll have to do some digging on that one.

[@zopilotegalaz1128]

The tcu uses pm power to control the center diff.and you just trow straigh power to it?

[@powerofyourbrains]

Actual pulse modulation would occur if you have a dccd (the diff control knob). In most models with just a tcu, the valve actuation may vary continuously according to detecting traction loss, contrasted by pulse modulation which would allow for constant partial lockup. Also, you get fwd at 12v, and awd at 0v.

[@pyroguyFTW]

I may be missing something, but I can't seem to find a clean way to wire this up for a car with VTD from the factory. I've got a '12 3.6R and am getting really interested in installing a controller for a sort of auto DCCD, and I have no idea where to find this info.

[@powerofyourbrains]

Did you check the forum link in the description? I think others have highlighted resources in the comments, and I know there are many more out there if you spend a some time researching. Regardless of whether it's a vtd or non-vtd, there are three major variables you need to know 1) the resistance between the solenoid and the relay 2) whether your mpt locks under power or absence of power 3) how you want to have it set up. There rest is up to you. There is fortunately or unfortunately no one right way to wire this in

[@ClintR2]

Hi,I am new to Subarus. Will this work for -2001 Forester. Also is there a write up on this?

[@ClintR2]

Also is there a diagram or instructions on how to do this? Just want to make sure I am doing this property?

[@powerofyourbrains]

Not by us. We wanted it to be broadly applicable due to different models and setup possibilities. Also don't want to be responsible for people attempting this without knowing what they're doing. As long as yours is an auto it should work just the same. Check the description and comments for forum links; I've seen some very good walkthroughs. The concept is simple, but there are things you should consider and understand before you go whacking up your harness, and there are different ways you could potentially set it up.

[@ClintR2]

@@powerofyourbrains what DPDT relay do you recommend? (one on amazon?) also what is the 2nd red wire on the relay? I see 2 reds, a back and the wihite and green.