Found in '15 Tundra rear diff

[D60]

2015 Tundra ~85k miles. I believe this is the first service on this rear diff, unless a quickie lube did it and the owner wasn't fully aware.

Ironically @The Critic had warned me worn diff bearings (I'm assuming this means carrier bearings) could be a problem on these.

Thoughts? I guess this could also be from wheel bearings, if you wanted to consider all possibilities. Could also be from careless assembly when assembled new, but that feels unlikely.

My thoughts are run it and check again in 10k or 20k miles. If more chunks are showing, further action is warranted.

 

[oldcodger]

Any abnormal noises from the unit? Some of that stuff looks like machining debris.

 

[drtyler]

Probably just junk from high miles on the original fill. Good thing the plugs are magnetic!

Definitely check again in the future just to be sure, but it's probably nothing.

I dumped the original diff oil on mine at 10k, and it was pretty ugly -- not that bad -- but subsequent change at 40k was clean.

 

[TheOilWizard]

Leftover debris from manufacturing? Probably a non issue. Looks like the magnet did its job.

 

[MSCH]

if the diff doesn't make alot of noise and doesn't make a loud clunk when shifting from revers to drive
I'd say F it, run it.

 

[D60]

Leftover debris from manufacturing? Probably a non issue. Looks like the magnet did its job.

Yeah that's what I meant by careless assembly when new.

I dunno, could be.

 

[Thermo1223]

Yeah that's what I meant by careless assembly when new.

I dunno, could be.

The little twirl of steel definitely looks like machining swarf.

 

[Hall]

Yeah that's what I meant by careless assembly when new.

I'd be skeptical of that. The pieces are all machined separately and then handled, moved, and eventually hand-assembled and for those pieces to remain are pretty unlikely.

 

[D60]

I'd be skeptical of that. The pieces are all machined separately and then handled, moved, and eventually hand-assembled and for those pieces to remain are pretty unlikely.

I know, it feels sloppy for a top tier manufacturer like Toyota, which is why I'm skeptical, too

 

[The Critic]

Ironically @The Critic had warned me worn diff bearings (I'm assuming this means carrier bearings) could be a problem on these.

Sorry, I meant axle bearings.

 

[D60]

Sorry, I meant axle bearings.

Ok well I don't see any gear oil at rotors. I actually haven't had time to shake the wheels yet, but if play were detectable by hand I'd think the wheel seals would be leaking.

 

[KrisZ]

I'd be skeptical of that. The pieces are all machined separately and then handled, moved, and eventually hand-assembled and for those pieces to remain are pretty unlikely.

The axle housing is machined too. And these pieces do look like machining leftovers that were not cleaned out properly.
Pieces like this are not from wear 100%. Hardened metal, like gears and bearing races never wear like this. They don’t even machine like this as they’re too brittle.

 

[Shel_B]

Were it my vehicle, I'd open it up and look inside and change the lubricant, and I'd do it as soon as possible.

 

[TheOilWizard]

I know, it feels sloppy for a top tier manufacturer like Toyota, which is why I'm skeptical, too

I think you might be surprised the kind of stuff that happens during the manufacturing and assembly process. These are mass-produced vehicles and far from perfect, regardless of manufacture. It would actually be interesting to talk to someone at an assembly plant and hear some of the stories about stuff they've seen while on shift.

 

[dfarr67]

I've never seen that kind of trash in a diff- and I've had a few go bad. It's going to be an expensive fix regardless- I would open, inspect, clean and if it looks ok run it until it makes noise.

 

[Astro14]

I think you got lucky - Those individual pieces were stuck to the plug - if they had been circulating for awhile - they would have caused a cascade of wear and you would have had far more stuck to the plug. I would say that the plug did it’s job.

 

[D60]

He does have a camper in the bed. It's on the lighter and smaller side of in-bed campers (kind of an "overlanding" thing, brah!) but I find it interesting that The Critic clarified wheel bearings (thank you) and this sees more weight 100% of the time than a lot of Tundras would with an empty bed.

I also recall one thing I never understood with the Tundras: IIRC the ring gear is 10.5" so you're in to Sterling/14b territory but it's a semi-floater. I have to wonder if a full float wouldn't be better suited here.