#1 Weakness of the Traxxas TRX-4 - What is most likely to break?

[@baxrok2.]

2 years and probably hundreds of hours of crawling and comping on mine and never a single failure! I've carried spare parts with me the entire time and never used a single one of them. X4's for life!

[@phantomstandard8281]

Seriously ? :)

[@bboss8048]

@@phantomstandard8281 if u dont do stupid shit, yes really. Its typically noobs who have no clue or mechanical sympathy that break parts all the time. Like Baxrok2, ive had mine since the day they were released, driven for literally 100's of hours and no driveline failures. Peace out!

[@jericobueno11]

I got one of this

[@phantomstandard8281]

@@jericobueno11 me too is really great looking and more :D

[@brycerc8660]

Yes same that’s why I got 2

[@ryurc3033]

So, I bought one when the first"kit" came out. In the last 4 years I have put at least 200 miles, hundreds of hours. Running it with a 3800 kv mamba x combo.....so I wasn't nice to it. In all this time, I have broken both fronts(replaced with Traxxas chrome moly in just the front) but kept the normal input gears in the rear. Truly remarkable how many hours I've had on it without that much significant wear

[@marymalone5188]

Even the best will break. Just have to upgrade. Thanks for the update Francis!

[@greggk1061]

Yes, no knock on the car here but this is usually the first one to break mechanically.

[@808maxstone]

That's the only thing that's every broken on my TRX-4 sport. Good video.

[@cbix86]

I’m running GPM hardened portal input gears in my TRX4s and never stripped again since, also massively cheaper than the Traxxas version 👍🏻 also work with the stock shafts so can get both front and back upgraded for less than the cost of just the Traxxas setup for the front axle 👌🏻

[@RCReviewChannel]

you have a link?

[@samanthaswisscat4713]

@@RCReviewChannel www.gpmparts.com/traxxas-trx4-trail-crawler-steel-45-cvd-for-front-2pc-set-gpm-trx44571-p-90084643.html

[@cbix86]

RC Review and here’s the rear www.gpmparts.com/traxxas-trx4-trail-crawler-harden-steel-45-joint-of-rear-axle-2pc-set-gpm-trx45968jt-p-90084700.html

[@carlzimmerman8700]

The listings say for the Defender, will these work on a sport anyone know?

[@cbix86]

Carl Zimmerman they work on all TRX4’s as they all have the same portal gears 👍🏻

[@douglaselliott8298]

If you don't drive your TRX-4 in a manner that would otherwise tear out the transmission, snap driveshafts, brake axles, bend frames, and cripple/kill the driver in a full-sized(1/1 scale) truck the "portal gears" will probably last forever. I am constantly gobstruck how ridiculously people drive these RCs and then complain about 'weaknesses'. A full-sized truck (or its driver) wouldn't last 2 minutes if driven 1/10 as violently as many TRX-4s are driven.

[@gmcevoy]

3:20 It's what is called "shock load". The same phenomenon which breaks CV's on 1:1 4x4's. When a wheel goes into the air upon accelerating, it picks up speed. When the wheel hits the ground again, "thwack!". There goes your CV... Or your input spur gear, in this case. It happens more frequently when bigger tyres than stock are being used. Funny, because in the years of service of my TRX-4, I never had this happen. I do put it through its paces, for sure...

[@montesamapping]

We have 4 model of TRX4 from 2 years and only one time we broke input rear portal gear, but when we open portals we found a MISSING BEARING... incredible, we have had NO problem for months even without a BEARING on that gear ! To complete our experience is important notice that we do hard crawling with commonly really low speed and obviously this help gears durability. On the other hand every week we do 2-5 km/3-5h on mountain paths reported by MyTrails and this is a lot of mileage for those vehicles.

[@tougesubaru420]

I KNEW IT! lol i literally broke the portal input gear the other day. went to the store and stocked up on a few haha

[@greggk1061]

same here

[@tougesubaru420]

Gregg K it shouldn’t even of happened either. A little vine got wrapped around the axle and caused the gear to shatter

[@tougesubaru420]

Castle Bravo they’re very weak in my opinion. At some point Id like to have my own gears made of titanium machined. Lol yeah it was bullshit. I was also running on a 3s battery at full bore so I didn’t really have time to catch it before it snapped.

[@jdsrcs8061]

Very interesting. I have not broken on either. I broke the rear axle housing last December driving and jumping in the snow. I did let it acclimate for the day before I drove it. What I always find interesting, is how some break the same part and others don't, but they break different part that the other never does. Crazy.

[@surfside75]

Spray WD40 on the plastics and let it soak in for an hour then wipe off excess. Many times more resistant to cracking now.

[@Jimmy2Horses]

I guess I don't beat mine hard enough. Six TRX-4s and never lost a portal gear.

[@JRLdesigns]

Yep, I bash one of mine hard, never broken a portal gear.

[@jordansrc8483]

I have two a sport and g500 and have only ever broken a front locker servo.

[@snap_fit8686]

Only a matter of time

[@jonthomas8487]

Exactly!

[@edsadventures3575]

I’ve had my trx4 sport from the day it came out. Never broke it.

[@maherkahala5269]

thamks a lot! ALL MY upgrades on my trx4 you recommended them

[@RCReviewChannel]

music to our ears!

[@gripking131313]

If your a trx4/6 owner and yet to have broken one of these gears good for you. But it is the weak link on the mechanical side of these trucks. My brother has a 11lbs bronco that he beats the life out of with zero issues for over a year. I install some trx4 axles on my vs410 rig and with in 2 batteries I stripped out the left front gear. All trx4 owners at the crawl sport told me it was the portal gear before I even pulled it apart. Went ahead and upgraded to the hardened goodies and zero issues so far.

[@NANNIRC]

Thank you very much for this tips... I've just finished my trx4 sport and I'm so happy (Hobbywing combo for crawler) I'm going to by spare. By now front because it is more stressed Ciao Nanni

[@shelleykentner4900]

I run all my trucks hard. Seriously, I beat the hell out of them. The only issue I’ve had with my 3 year old trx4 was when she was new and the rear axle broke in 2 and cracked the solid half of the pumpkin. I sent pictures of it to traxxas and they happily replaced it. Their customer service is fantastic!

[@gettinglost316]

Thanks for all the info you've made so far regarding what mods are worth it for the TRX4, luckily my only purchase before youtubing it are the Traxx

[@WillsWorkshop]

I have clearly looked after my TRX4 Sport too well, my gears are still perfect even after 2 years of abuse, just uploaded a maintenance video to my channel stripping the portals and diffs

[@sethflood1545]

You’re awesome man big help getting into the crawler stuff!! In the middle of assembling my trx4 right now haha just watching videos for a break 😂

[@joshsrcs]

I’ve only broken one of those after a year of Super Hard Bashing and Backflips with my TRX4 and also I get the wheels stuck solid all the time and it’s only now ever broken

[@octaviorodriguez6849]

This thing is built to last. Well minus the steering servo and motor. I have the 2021, all black Ford Bronco!. Over 250 miles of trailing, hiking trails in my area and all I’ve had to do is apply grease to the portal axels and differentials as part of routing maintenance once a year and looks and feels like it’s ready for another 250 miles!!!

[@zkgarage1939]

Mines doing good. I've had mine since 2018 and only replaced the servo 1 time. I don't know if I'm not bashingbjard enough but. She's floating good.

[@KTMcaptain]

This is why Holmes doesn’t recommend using the auto function on the axe. Bind up the wheel and torque transfer will go through the roof... but first through this input gear. . I’ve yet to have a drivetrain failure, and your slipper should be set to break the torque transfer above a certain level. . I don’t jump my trx6 though, and I do backflips with my revo and Capra. But the Capra input gear is pretty narrow, so I’m not sure it’s going to be much stronger.

[@baxrok2.]

Yup!

[@alexandreanonimous7056]

Great observation 👍 it's something to look after and now I'm sure to keep the same engine

[@cool.stuffs]

I have 5 and still haven't broke one and I beat the hell out of everything I own, but I have seen people on the forums break them.

[@joshwood7450]

I have two trx4 and had to replace that gear in both of them

[@kennethnorling5108]

Good video, question is if you strengthen the portal input gear and use the heavy duty chromoly input shafts, what's the next weakest link? something in the transmission or the drive shaft? What's cheaper and easier to replace?

[@kevintaylor1626]

Very true had to replace one front of my Defender after around two years also.....

[@runnerbaba]

You are correct. Thanks.

[@vanlifethetravelinfranksho5611]

I have the defender from Traxxas. My second T and my last. Super expensive here in Canada. The inner fenders drove me nuts. Made putting the body on a major jiggle and wiggle event with plenty of cussing. Inferior electronics, had to stick paper in the transmitters battery box just to keep the batteries in place. Flimsy body tears right by those inner fenders as well. My Axial has gone through hell and there are no rips. All in all, wish I had bought something else but I'll make it work.

[@jessev4615]

🤔 i bought mine right when they cameout & have trailed it ever since. I use it to tow my trailer alot with several different of my 8 , 9, lbs SCX trucks onboard never broke those gears. Iv busted Servo 3 times, servo horn, iv snaped my hex pins in rear towing my trailer, locking cable Twice. Have to watch them from know on, been a rock soild truck to me.

[@airbornerc4654]

Congrats on 40k subs!!! 😄👏👍

[@RCReviewChannel]

Thanks! 😃

[@strikefighter0497]

Yeah it really is a weakness when you start adding weight. I have an all brass/aluminum front axle, and my rig weighs almost 12 lbs. I have broken 3 input gears within 2 hours of total crawling time after putting all the brass on. Definitely the sacrificial piece in the driveline. I'm gonna buy the chromoly ones and see if they last.

[@that_clapped_out_singlecab9372]

I’ve had mine for about a year now my dad and I do heavy crawling and heavy off-roading we try and drive them like they are real trucks and after that year and also putting shocks that max the driveshaft angle out and I just now finally cooked my differential and I smoked my low gear in my transmission crawling in a river the other day these things are bulletproof

[@zacharypoland2212]

I think if you have the diff lock option this is not as much of a concern, when I run my trx4 fast I never do it with the diffs locked unless absolutely needed, with the diffs unlocked it acts as a cushion of sorts in the driveline

[@sprather84]

What's up Francis that's funny that you say Nobody Breaks the axle because the axle is what broke on my Sport and my TRX 6 and I replace them both with the chromoly parts right at the U Joint inside of the gear the head broke off of the axle on both of my trucks

[@raptorjesus5488]

I had the same thing happen on my Trx 6. Front right cv blew up.

[@shaunsanford2253]

I know this is years later but I've been lucky with both mine. Upgraded hh trailer master and 1080p esc. Been bound up pretty good and no input damage

[@jeanst-amour9621]

Maybe it was engineered that way? I broke one as well when a wheel was wedged tight under a boulder and I gave it all it had! I'd rather break that than somewhere further up the driveline, right? No rc is unbreakable; if you strengthen something it will break elsewhere. Great video! Now we know what spares to have on hand!

[@RCReviewChannel]

No. If they engineer a failure point, it has to be easily accessible and repairable. Chewed gears in the casing will really damage the other gears.

[@HardupRC]

Yes, I do have it handy. I always have spare gears.

[@KTMcaptain]

Panhard mount, servo, and lights are all I’ve broken. Thing’s been a beast.

[@mnmvuk]

Just curious, Francis. When this abrupt one wheel landing occurs and breaks this part, is the front diff locked by chance? I'm wondering if it was unlocked, would the stress be relieved by much less resistance as the forces could be absorbed into the other wheel. Great review as usual. Haven't broken one yet but I will stock up on one for each axle.

[@RCReviewChannel]

When the diffs are unlocked, this problem is way LESS LIKELY to occur. The energy will go to the other wheel, not the locked drivetrain. Good feedback!!!!

[@BlvlWmpower]

I'd imagine the high drag-brake we all use puts some strain on them too.

[@CommonZense]

No doubt. Mine has been leveled down.

[@morris4069]

That’s the only thing I have broken. Rolled down a big climb from about 15’ and must have blipped the throttle at the wrong time trying to get it to stop rolling. Only one gear was trashed, picked the shrapnel out of the plastic case and back I business. Probably should order a set on my next parts order. Give us a vid on scx24 shocks, that’s my only complaint on those.

[@coolbear457]

Just had to work on the bearing that sits on this gear, it got really bound up and nearly caused my diff to blow up, luckily I caught the one tire not spinning. Could have been avoided by greasing it but that’s my fault.

[@JohnConnor12]

I shattered one after a pretty nasty fall right on the front end. Mine sounded a lot worse than yours though. It surprised me a bit to see that break, but my TRX4 has been to hell and back. Bought a replacement and a spare just in case.

[@billtrimble4882]

I bent a rear axel, no idea how. I am running a Holmes puller pro stubby v2 2700kv in my trx4. Orders the upgraded axels, didn't realize I needed a new gear. Oh well. It still runs with the bent axel, I found it during a normal maintenance day. I have broken a front input gear, once in my Defender, all stock electronics. Bound it and boom.

[@JvD1985]

My TRX4 defender has allllllot off milage and is still going strong. Its crawling, not bashing or jumping. Crawling is like barbeque.. take your time and enjoy. No rushing 🤣

[@Thepreppersbunkeroutdoors]

Good video! Im sure far too many people will be offended that you DARE say their rc has a weakness lol. "I own 3,000 trx4's and i race them at king of the hammers and mine has never broken!!!" Haha People are weird.

[@RCReviewChannel]

Exactly! "Mine has never broken so there is NO problem." "User error!" It's just a stats/data issue. It's the one most likely to break first.

[@Mark_Dee]

I would have been great if you have shown how to assemble/disassemble the input gear from the shaft.

[@NoLimitTouge]

It's literally the same as in real 4wd. You go through some ruts lift a front wheel, it spins and hits the ground... ...bamm! The CV is cactus 🌵 caused through the shock load.

[@RCReviewChannel]

Yup. And portals put extra stress since since it is big gear force into a tiny gear that is locked.

[@Bikes_N_Adventure]

Lol "cactus"

[@svendemeyer6278]

Nice vid. My trx4 is as old as yours. I have the green one. First things i did was trim the body, and put in a mamba monster X and 1515 can (2200kv combo) The only thing i broke are the 1st en second gears inside the gearbox (when driving through sticky mud) beside that, the thing is still driving fine, slow when i want it and Fast when i need it. My portals gears are still in great shape. But after seeing this... i wil order some 😂 you never know.

[@teamsargentrc6399]

I have had the Gen 8 now for over a year and the only thing I've ever replaced on it still was stock electronics and I've beat the snot out of it... Is the input portal gears and only in the front...

[@Tommysmess]

I can't wait to purchase one of these trucks

[@billderas3420]

FC. You have me beat by six times in regard to breaking portal input gears...LOL

[@RCReviewChannel]

Yup! Although I did hand my trx4 defender to a kid last weekend. 2 minutes... broken portal.

[@plasticspoonrc]

Excellent information to know. Thanks for sharing. Do you or anyone else have a fix or solution for the extra smelly tires? Every other TRX4 that I have has toxic smelling tires. They all are in bags of baking soda but I don't think I that will get rid of the odor. Should I just upgrade them?

[@RCReviewChannel]

Yeah, just get rid of them. The tires and wheels are vented with holes so water probably got in them and is stale and moldy.

[@plasticspoonrc]

@@RCReviewChannel these are brand new tires that have the toxic smell. They never have been in water..

[@unc13buck]

I'd have to see how people break these. I have had mine for about a year and done tons of forward and reverse wheelies and regular trail abuse and have yet to break the stock ones.

[@jondoe6618]

I agree. In stock form they will handle 6s power with ease. Kevin talbot beats his harder than anyone out there.I am not real easy on mine either.

[@RCReviewChannel]

Jump at 12 mph, land awkward on one tire and that will probably do it. I handed my car to a kid last weekend and portal was broken in 2 minutes. Hand anything to a noob kid and they will find the weak link quickly.

[@jondoe6618]

@@RCReviewChannel Everyone has a different experience i guess. I have jumped mine hundreds of times, got tires jammed into holes so hard the whole truck wheelies on 1 tire. Never had one problem.Best overall rc in the world by many.I have seen a trx jump almost 100 feet and not break.

[@greggk1061]

@@jondoe6618 Best for sure. But have broken mine 3x. Twice in the hands of my kids.

[@-Ola-.]

When did people start to by a trx for jumping?

[@coajokazz]

What tires and beadlocks are you using on this trx4? Looks awesome!

[@O-YKEM]

Thank you very much!

[@RCReviewChannel]

You're welcome!

[@maniac1628]

The electronics are great in the trx 4 I stand behind them the steering servo yes I agree it’s under powered the portal gears are fine I’ve never stripped mine

[@Thepreppersbunkeroutdoors]

Is the gen 8 portal setup stronger or does it have the same weakness.

[@RCReviewChannel]

Same. They had some plastic gears in the drivetrain so those gave out first.

[@spencer1244]

There are tons of aftermarket options to bulletproof the portal input and output gears, from KYX, Yeah Racing, traxxas, devil rc.. Front and rear, All made of better materials.

[@rc-daily]

Is it really a weakness though? Those gears can straight handle the abuse. In a stock truck you would never break it. I run revolvers and ive never broken one in either one of mine.

[@gm3353]

i love the look of the defender, the light upper weight of the blazer, and the pin-less and other upgrades on the new bronco. can't decide which to get... is the defender substantially weaker performance wise than the blazer?

[@diegoarjona7605]

I think all the trucks have the same electronics and parts etc the only difference I know of is the wheelbase lengths varies between the different model aswell as the mounting systems and inner fenders and bumpers besides that I think everything is the same

[@abzyberdy]

Broke front left one today after 3 years of use

[@TT-yg2np]

I've had the portal gear go out on my TRX4 & on my TRX6

[@ChrumkavySuchar]

Interesting. I have only 1x trx-4 (bronco) , with Axe 550 3300kv system , with 15t Pinion gear and running 3s all the time -> i am getting pretty high speeds. I am more bashing then crawling my trx-4, and really hard. Few things broken, few bodys broken, but this portal input gear - newer :O . Maybe they are delivering different versions / different quality of this part ? Strange

[@Nanan00]

Sounds like an opportunity for someone to make the portal input gear out of 300m, the material that real car drag racing trans shafts are made out of.

[@RCKYOTA]

The portal gears are fine ive had 2 of the actual axles that hold the tire on break off right at the nut

[@RCReviewChannel]

Ah yes, that's the wheel carrier.

[@RCKYOTA]

@@RCReviewChannel do you know if there is a hardened stub axle?

[@jeffparryncc1701]

Is that your washing machine going in the back ground? LOL

[@RCReviewChannel]

Unfortunately yes. Wife is banned from the garage/studio now.

[@jeffparryncc1701]

@@RCReviewChannel he he

[@swashbucklingadventures9929]

Traxxas has "heavy duty" ones for 100 front & rear. They just as good as the ones you mentioned? Also, wondering if YR axle swap would solve this all together?

[@brendantate5315]

I have two trx4 and the redcat gen8 axe. Are you going to review the redcat wendigo rtr or kit? I have the wendigo kit coming in and the Hobbywing brushless 540 motor . Also the brushless and 25k servo, receiver. I think the kit will be a great build over the rtr. I will use a Redcat transmitter from my older redcat volcano epx pro. I was going to use the electronics from the volcano, but think it's a real pain to do that and opted for new electronics. I think my 2s batteries will be enough. My trx4's are still running good.

[@bigheadrc]

is someone drying clothes? Enjoy your videos 👊👊👊👊

[@RCReviewChannel]

Exactly! Dammit!! Mike is sensitive.

[@bigheadrc]

RC Review its ok.. Your video’s really help me upgrade my rc’s... Thanks so much 👊👊👊👊

[@splintergg]

Somewhat like on a real car, if you drive them to hard and the front wheel leaves the ground and lands with the gas on, the CV is usually the thing that breaks

[@LeftenantMalachi]

My portal input gear broke on my TR4 Blazer, but also my axle housing broke too. Do you have a link to a stronger front axle housing for the TRX4?

[@chrisjohns4817]

I did just the opposite corkscrewed the shaft gear was fine.

[@RCReviewChannel]

Interesting! That one has more teeth. But this mesh is the one under most stress during big hits and stress.

[@_tom_p]

Yep, I've broken 2 of them now. There is a weaker part than this on the TRX-4 Sport, though - the spool in the front and rear diffs. I've broken 3 of those!

[@maniac1628]

And no one I know has complained ablit the portal input gear stripping

[@6ickness1]

do you have a video on how to make the front axle move faster then the rear

[@RadioReprised]

Could you Cryo treat the stock gear?

[@jasond1245]

Think some aftermarket parts would fix this.

[@RCReviewChannel]

Robinson Racing please

[@jasond1245]

@@RCReviewChannel good too know trx4 is my next build

[@johnsdad092009]

Ive been running gpm machined steel gear for over a year no issues. Check them out cheaper than traxxas parts as well.

[@Lokithefeline]

funny you made this vvid, i was actually on phone with traxxas to find out if they had stronger axles evven tho i havve yet to break one. ya kinda expensive for sure. is there aftermarket upgrades for it not made by traxxxas?

[@rreynolds9056]

Have you encountered any of these failures while running open diffs? Personally, I've yet to see any mechanical issues on my Bronco, although 80% of the time it's unlocked.

[@RCReviewChannel]

Ahh, it is less common with open dffs. When a tire is forced to turn by impact, the opposite tire will turn thus dissipating the force.

[@scrooem]

Thanks!

[@RCReviewChannel]

Welcome!

[@jrc-fabs1634]

Yup, I’ve broke one. I heard that the upgrade on it from traxxas is even weaker

[@deepfriedspace6725]

Is this only a problem with locked diffs? My trx4(bronco orignially) is almost 4 years old with bashing and jumping included.the only thing i ever broke was the front bumper mount and after that nothing else has given out, i did put a castle creations mambax and 3800kv crawler motor, but ive never broken anything else.

[@dolan948]

2:06 asmr disappointment 😂😂

[@sitlos.]

I know dirt and junk can get in there, maybe that what’s causing ur breaks. Maybe thicker grease or a boot would help? Just an idea, couldn’t hurt anyhow. Lol. Have a great day!

[@sitlos.]

I have a lot of grease that’s come from all the front end gears and it makes it look messy or dirty. Drives me nuts. Lol

[@sprather84]

@@sitlos. I've never seen it leaking grease on anybodys r u sure everything is tight

[@duder280z]

I pop bumper dragging wheelies on my TRX6 and haven't broke one yet. I'm sure I will soon though. LOL

[@david-kl5xj]

Thx you ar verry help full

[@loum7008]

Funny, broke mine 2 days ago after jumping it off my neighbor's Rustler ramp. Guess I'll stop doing that!!!

[@imchris5000]

I have shattered a few portals most of them the front left. I keep a stock of them. I have broken the front axle shaft once too it shattered at the pin theres not much metal around it

[@ElCapitanKG]

What is a cheap reliable brushless upgrade?

[@JoeOvercoat]

I cannot help but drive my crawlers as if I’m a farmer where this is my only truck, and this is the road to my house, and I have to do it again tomorrow, and the day after that. But then this boy has not bought a trx....still running an original scx.

[@MrLunithy]

So even Traxxa$ suffer from HobbyKingiti$ as well lol.

[@TCnML]

I prefer the SSD portal delete.

[@prinznapp2018]

First time I hear that there is a problem with the portal gear.. Never had a problem with mine Defender or sport

[@RCReviewChannel]

We have dozens of reports in our FB group. It's still a fairly rare occurrence for this good vehicle.

[@Mtbmi]

Never had a issue with it on my half and I run a 3800kv with the 2 speed on mine

[@RCReviewChannel]

It is a sturdy machine.

[@ka4172]

Better break the cheap part than a way more complicated to change (in the field) gearbox part. In 4 years i have never breake this part (maybe now on the next weekend ha ha).We try out every hard climb and trail that we can find .But have never run more than 15 miles an hour.

[@maximus7714]

I greased portal's and diff with cheap smelling marine grease is this safe long term for plastics ??

[@Chongy28]

Thought i broke mine recently but it turned out that i sheared the locked diff spool in my sport