Rear Differential gone

Hey Guys, thought I’d share my Thanksgiving evening adventure.
Long story short, accelerating into the fast lane on a hwy at night, thought I was rear ended by someone, nope, would not move in drive, put it in 4x4 and was able to get off hwy, had it towed to my mechanic!
He sent me these pictures, I have kept up maintenance, as early as a few weeks ago ago, had a rear wheel bearing replaced, front two a while ago! He is getting a complete used assembly, $1,800, using parts from it, will cost me $2,700 to have it fixed!
Truck is a 2016 sport, 150k miles!
What do you all think, anyone else have to replace one seemingly this soon!!
I am shocked, been a great truck!!

 

1800 for a used 3rd member is steep. You can ship both front and rear to ecgs and get new gear with the proper front bearing for cheaper

 

Did you notice any weeping/leaking over the years? I had the weeping rear end TSB done the first year of owning my 2016. See post #1931 for PDFs of the TSB.

https://www.tacomaworld.com/threads...ble-loss-of-control-of-vehicle.488536/page-97

 

A tooth broke, and then a chain reaction happened.

Don't see it too much on a 3rd Gen.

But 8" E-Locker trucks in the 1st and 2nd gens, it has happened.

 

2016 Sport may have 2nd gen axle (A04)

 

While one may never know, I am curious if this is related to the wheel bearing repair,,, awfully close timing. Who knows, with a 150k miles, anything can fail, just the nature/risk of owing a high mileage vehicle.
Did they forget to refill, or did it leak? I am sure if it was the latter, you would've noticed the fluid.

 

Everything looks dry (even the paper under the bits rag), was there lube in the diff when it was opened?

 

I was also wondering about the rear wheel bearing replacement, it could have lost a lot of gear oil. Timing is why I’m suspicious

 

I agree it does look dry

 

you can get a rebuilt with all new bearings and gears from east coast gear supply for cheaper than an unknown used rear end. also a good opportunity to add an lsd or locker

 

I'm with you, the timing is suspicious. Occam's razor, the simplest answer and all...

150k is high mileage, but not for a diff, unless it's used and abused.

I'd be curious to know if there is "diff oil" on the previous wheel bearing replacement parts invoice. Not sure if the amount you could lose during that job would cause this, though.

Also, is that staining or rust on the face of the diff housing? Perhaps it was leaking, but if it was, why would the mechanic not have noticed that?

 

Very dry!
If it’s the same shop that did the bearing a few weeks ago, they may claim it was cleaned for pics. But look in, they would’ve have had to flush the hell out of it to get it that dry. Gear oil is thick and coats everything.

 

One of my first thoughts, can't prove it tho

 

When they were finishing up the Rear wheel bearing, I actually did see them filling it, no leaks on the driveway or in my usual spot at work, does look dry, I'm at a loss as far as what actually caused it, will probably never know. Already had it towed to my mechanic and agreed to the replacement, now I wish I did not, and couldn't drive it, kinda stuck there. Expensive learning lesson!!! Thanks for all the replies!

 

No, none at all

 

Your diff wasn't dry. You can see the light shining off the oil covered parts. Since you are just south of me, my bet would be, at some point you had a sudden traction event from ice to dry pavement that might have shocked the gear and weakened it. But then again, it may just be a fluke failure.


Here is what a no fluid failure looks like.


The little fluid that was in the diff burns and discolored all the bare metal parts. It also stunk really bad.
This is a core I bought for a future project. 3rd gen with locker. I already have a new take off E-locker for this housing.

 

Would weight have anything to do with it, my truck weighs in at around 6,500 lbs
Have a canopy, tent, Decked system, etc...pretty heavy, and I have a somewhat heavy foot

 

The weight can put more stress on the gears but more so on the bearings. This type of break is more an instant break and a heavy foot would be the more likely cause. I wonder if there was play in the pinion causing deflection and pop goes a tooth during your spirited highway on ramp run.

 

Have you done many deep water crossings?

 

I’m thinking that you might have waited too long to change the wheel bearing, maybe some tooth damage might have occurred while driving with the bad bearing. I’m sure you heard and felt some bad things from the rear prompting you to change the bearing.
I had a bearing and seal go out on an S10, the rear end whine during acceleration never went away after that.