Rear differential failure

I was heading back to town yesterday afternoon, doing about 70, driving perfectly normal. I crossed a small bridge and right after I crossed, it sounded like a baseball bat hit the side of the truck (best way I can describe the sound). It was so forceful, the radio came out of its slot. I pressed the gas and the engine just revved as if it was in neutral. I coasted to a stop and looked around the truck, and it was obvious that I didn't hit anything. I put the truck back in drive and it made a loud grinding sound. Same for reverse, leading us to believe that the differential had failed.

Got it towed to a transmission shop shortly after, and the guy said he had never seen anything like that happen on a Tacoma before. He didn't give too many details but said that the differential was completely shot and would have to be rebuilt. I know this guy really well, he's a family friend, so I know he's not just trying to string me along. He said he was essentially going to have to replace the rear end.

Has this kind of thing happened to anyone on here before? I've been looking around the internet all day and I can't find anyone else that it's happened to. Just trying to understand why and what would make this occur.

 

I have read several threads in here about the ring gears being weak in some of the rear ends of the V6 trucks. Do you 4 wheel a lot or drive hard off road?

What year model engine etc...

https://www.tacomaworld.com/threads/trd-sport-vs-off-road-4wd-question.371289/#post-10158727

https://www.tacomaworld.com/threads/busted-spider-gear-maybe-worse.310340/page-2#post-7991249

https://www.tacomaworld.com/threads/rear-end-shot-on-a-2011.309358/page-5#post-7962703

 

please let it not be a TRD OR with the 8.0 e locker..... that will give the sport guys fuel to the "8.4in non elocker diff is stronger" claims

That sucks OP, give east coast gear supply a call they can probably hook you up with a full third member for cheapish.

 

Is your truck still this one? Looks like a base model or SR5? https://www.tacomaworld.com/threads/pictures.66888/

Diff failures for non-TRD Off Road models are supposed to be relatively rare. Have you been changing the diff fluid every 30k? Driven through deep water? Breather extension mod done?

 

Sorry for your problem, keep us posted on the rebuild and let us know if any forensics are done that determine 'why'.

In the meantime, find the radio installer and recommend they upgrade the quality of their work. (guessing it's not an OE installation)

 

What was the state of your rear end gear oil? It can easily happen if it runs low.

I had it happen on my 89 pickup. It had a rear end leak that I would top off periodically. Once it ran low and at 65 on the highway the rear end seized locked the rear tires at full speed then ripped the bearings loose so the truck could move while making horrific sounds. Rear end was totaled and diff housing had to be replaced. Fortunately I sensed something wrong right before hand and put the manual transmission in neutral, saving the driveline.

 

Rear diff issues are subjective, but usually the failure is more subtle by way of the pinion bearing going out with a noisy "gear whining" on deceleration as opposed to yours grenading all at once... I rebuilt the 3rd member on my 1st gen for $200 & change with a bearing kit...

 

Should have been a little more specific, my bad. I have a 2006 PreRunner SR5 4.0L V6. I bought it used in 2009 with 55,000 miles on it. The only mechanical issue I've ever had with it before now is having to change all three universal joints.

I don't take it off road very often, never have needed to. I have a feeling whoever owned it before me drove it around (or through) an area with saltwater.

Never have messed with the differential oil, unless it was changed when I got the u-joints replaced. Not too sure on that one.

 

You probably either ran your rear end dry through weeping axle or pinion seals or like you mentioned, it could have been contaminated with water, salt or not.

I keep a five gallon bucket of universal gear oil, 89w-90 around, and usually every gear box gets checked or changed EVERY year. The last rear end I had to change was a van I bought with shattered spider gears, and that was about 15 years ago.

However, it should have started to make noise a long time before it failed. Your situation sounds like the bearings seized then it grenaded. I suspect a wrecking yard in one of the better options at this point, just try to match ratios, and you can swap your brake backing plates and drums.

I have known many, many folks who have run rear ends dry with terrible results.

Howard

 

U-joint replacement is a distinctly separate maintenance action from changing the diff oil. It's possible the diff oil has never been touched in the 9 years since it left the factory. How does the diff oil look now? Is it a thick black sludge?

 

yessss!!! not a trd elocker axle.


Sounds like oil ran dry or was shitty. Though usually like stated you will hear the pinion bearings first with bad oil.... happened on my moms 4 runner.

 

Does the quality of the fluid in your diff make a difference on differential life?

 

That sucks... Call up East coast Gear supply... Got a rear from them 2 years ago. Best deal, customized the way you want it, and best warranty i could find. Good luck

 

yes, of course
but not really

if it meets 'spec' then it is good enough
-----------------------------------------------------------------------------------------------
the problem with diffs, is there are places crap can get in there (breather)
and places fluid can leak out without being noticed (rear axle seals into the drums)

so...over the years crap can be getting in contaminating it (like a hot axle covered in cool mudwater)
or the level can slowly drop over time and it starts to run dry

 

I just blew out my rear diff this weekend. I thought I dragged the bumper bc of the grinding. In the end, drive shaft was spinning w zero power at the back wheels. I was 11 miles back in rough Rocky Mtn terrain heading back to camp. Fortunately, I was there w good friends and 2 other Toyota's to help me limp out the next morning. They were giving me odds of 3-5% to retrieve it. Otherwise I'm guessing I would have shelled out $2-4K for an extraction. So we winched and towed it thru 4 major spots that were 4WDL intense. I blasted through the rest of this trail w 2WD in the front only. I rallied that thing harder than most would in 4WD. It was a partial miracle and that OME kit saved my ass! The dealership honored the warranty straight up and rebuilt the diff. I was shocked they didn't try to do any weaseling since I have an aftermarket suspension. A small step in restoring my faith in standing behind your product. I have 32K on my 2013 Taco and did absolutely nothing wrong. I was simply doing things a Taco should be more than capable of handling. My other Yota friends have made this trail trip a few times w no incidence. I never got to see the parts but I was told it was a porous carrier casting that cracked, broke and took took out all the internals.