Rear Differential Completely Destroyed at 25,000 kilometers.

Joined today to share my disappointment with my new Tacoma. Previously had a 2009 TRD Sport which was bullet proof. Always used it like a truck including towing, off roading, hauling dirt, soil, rocks and dirtbikes, etc. Had this new truck for just a year and used it like a minivan thus far and check out the pics. Best part is Toyota Canada actually took a day to decide if they were even going to cover it! Asking me questions about how fast I drive in 4x4 and how I shift the transfer case, etc. Even if I was a complete moron there is NOTHING you should be able to do to shred a ring and pinion before doing damage to other components such as CVs, u-joints or side axles. So disappointed with this generation of Tacoma.

 

the rear Diff just grenaded like that for no reason?

 

Yep. No reason. It was a snow storm that day so I did have it in 4high for a drive down to my friends house a few blocks away. However this was in 2 wheel drive high n the drive back to my place. I could MAYBE understand if I had a habit of spinning on gravel and then hitting payment to try and get a chirp out of the tires or any other list of things that MAYBE should cause this. With my old Tacoma I've pulled 3/4 ton diesels with 8.5 v-blades and busted 10000lb tow straps. You name it I did it with the old truck and it never skipped a beat. That was with 207,000kms or 130,000 miles. I see many people complaining about the howl in the back differential which I didn't have. I'm thinking bad bearing messed with backlash and she slipped? Maybe some filings left in the case on assembly? They of course checked the oil for type and volume and it was normal. I never touched this truck. NOTHING. Now I cannot trust it to do anything but baby down the road. Useless.

 

Can a mod please move this to the 3rd gen forum (dangerous move - I know) so other could share their experience? I'm not sure this thread is relevant to the new members' forum.

@98tacoma27 @chris4x4 @MTgirl

OA

 

@2016LimitedTaco

I know you're pretty irked about the whole thing but it may help others avoid a similar fate if you go through what happened in detail. You were just on snowy asphalt? How did the truck react? It's incredibly difficult to imagine the rear end grenading in 2wd just on the street. I've seen it happen while on a trail with a locker engaged - but that was someone being a clown with the skinny pedal.

I've had concerns about the diff howl and the tire-like noise when slowing to a stop; but I'm too afraid to mod or even mess with my diff oil if this is in the cards. This sort of thing is a big deal if there wasn't user error.

OA

 

Yea there's more to this that OP is not telling us.

 

No worries I would love to help people out and explain. I had a "witness" in the truck with me too. I was in 4x4 as my buddy's driveway is quite steep and it was slippery. Had it in 4high (always unload the drivetrain to shift transfer case and even though "technically" you can shift as long as you're under 100km/h I NEVER do) and went up his driveway. Came back down his driveway and stopped before I hit the pavement to go back to 2x4. So at full stop and in neutral (again I know you don't need to be in neutral to shift on the high side from or to 4x4 but I hate the CLUNK you get if you don't do it with an unloaded drivetrain) shift the transfer case back to 2x4 and when I went to drive away I heard a loud pop / bang and then high frequency grinding. Assume it was a bad shift of the transfer case so went back to 4x4 and moved truck (she would move now as the front was pulling the back) to cul de sac and then went back to 2x4 and same noise. Had my buddy lie on ground and watch the driveshaft as I really thought it was in the transfer case as it was such a high frequency grinding and driveshaft was spinning freely without even pushing accelerator and then I knew it was the rear end that was toast. I actually still thought it might of been a side axle as I would never of thought in a million years it would be the differential. It's not a lawn tractor! Even if I was a moron that abused the truck this should NOT happen. No one will ever convince me otherwise. I did things with my old truck that pushed the limits and I was completely ready to deal with any consequences and it never skipped a beat. Put three u joints in the drivetrain in 200,000kms and a front driver's side wheel bearing. That's it. Ran royal purple in diffs and transfer case and Toyota WS in the tranny but that was after many many kms.

 

You got teeth that have broken off. Me thinks something was wrong with the material and/or something got loose and put the gears in a bind. Might check for cracks in the housing or a failed bearing. Sucks.

 

Mileage?

Edit: Nevermind.... dumb post. It's in the title.

 

How so? Parts fail, it's uncommon but plausible.

 

I agree completely. Something had to shift to change the backlash to be too loose and they stripped or there was something left in the case on assembly or ONE tooth broke off and then chewed everything up. I asked if they made sure they got EVERYTHING out of the case and axle tubes and they said yes but I have very little faith. If nothing else I don't think the techs would do many differentials and they can easily be done WRONG. They are just replacing the ring and pinion and gasket. Again I would of rather had a complete differential fully assembled.

 

A couple things i question personally.

1. Where the heck do you live if you need to go 4x4 on a driveway?!
2. When you switch to 4x4, don't you generally start in 4lo?
3. Isn't there a delay from when you switch from 4x4 to 4x2?

 

I did nothing wrong. If I had done something wrong I would admit it. I am fully capable of putting in a ring and pinion correctly and it's actually pretty cheap for the gear set. That is not the point. Even the tow truck driver (not Toyota but called by Toyota Roadside and independent) said this was the second Tacoma he had ever towed in his career. His exact words were, "They just don't break down."

 

From his story, it's not a gradual failure. Something he was doing provoked the parts to become unstable and wear at a rapid pace.

 

So what you're saying is. You were at a deadstop, put in 2wd and gingerly drove off and all that damage happened, from a complete stop JRA.

not buying it at all. You did a colossal amount of damage, the kinda of damage that doesnt happen at 5mph

 

1. Where the heck do you live if you need to go 4x4 on a driveway?!
Nova Scotia, Canada. We had about 30 inches of snow in 24 hours and it was still snowing.
2. When you switch to 4x4, don't you generally start in 4lo?
Never use 4lo. Have to be full stop, in 4high and in neutral. 4lo I guess for some serious offroad crawling or hard tow from dead stop maybe but only ever use it once in a while to keep the transfer case shifting.
3. Isn't there a delay from when you switch from 4x4 to 4x2? I normally wait a few seconds and you can hear a tick behind the glove box and the light goes out to know she's done switching. Then I switch back to drive, reverse, park, whatever and resume operating.

 

exactly going 5mph wont completely shear off pinion teeth, maybe at 105mph,the funny thing is the OP is consistently referring back to a 2009 Tacoma as if all of a sudden in 2016 the rear diffs just grenade and no one knows why. But he has a witness??

 

Was your differential howling or humming when you were on the freeway? This is the fourth or fifth rear diff I've seen someone post about blowing up here on the Turd Gen.

 

I was thinking improper heat treatment made them brittle or the gearset was not adjusted correctly from the getgo and was a ticking time bomb.