Brand new ORP and the rear diff fill bolt is leaking

I'm so bummed, I noticed there was a small leak coming from it, took it to my local dealer and they did fix it by putting in a new washer and bolt... but then they told me they noticed it was still leaking so they took video and pictures and sent it to Toyota. They said they'll wait to see what can be done next.

Anyone else had this issue? If so, what was the solution?

 

^There's really no reason for the fill plug to leak because the oil level should be at or just below the fill port. Check if the breather dust cap on top of the diff housing is free to move.

 

It's been at the dealer since yesterday. I decided not to touch it since it's still under warranty... and they did cover it under warranty fortunately. One thing they mentioned it seems like the washer was broken from over-torquing the bolt, so not sure if it came like that from factory or what.

 

Good ole impact on every nut and bolt.

And how would it come like that from the factory when they changed it once?

 

I just picked up my 23 TRD ORP two weeks ago, and it fills my garage up with the smell of gear oil. I wonder if mines is leaking there too!

Definitely will check when I get back home from the cabin on Monday.

 

I removed the fill plugs on my rear diff, front diff and transfer case to verify they were properly filled from factory (front diff was low). They were not over-torqued from factory (or last place to tighten them) and no one had removed them at the dealer. Perhaps they are checked during PDI at port? Anyway, I was test driving mine within an hour of it hitting the dealership. Still had some white plastic on hood. I can’t imagine the Japan factory over-torquing them. Then again I can’t imagine the front diff being low either. But who knows about port or dealer?

 

Alright guys! So update.

The dealer got a new washer and a re-filled and re-torqued... it was still leaking.

After they told me a more "experienced" tech looked at it and supposedly shaved the bolt and were able to torque it perfectly and no more leaks.

All covered under warranty! I am happy I took it to the dealer because at least I have the paperwork and such just in case something else happens.

 

Shaved the bolt?

Negative for me if that was the fix.

 

Exactly my thoughts. If it happens again I'll bring it to another dealer.

 

Exactly. What does that even mean?

 

Exactly. I am not sure what it means.

My advisor is clueless about mechanic stuff and I couldn't talk directly with the tech so idk the exact details.

 

I wouldnt take the car with that bandaid fix.
The shaved nut could come back to bite you. Toyota can say you modified it if it leaks again.
Hope your Toyota paperwork clearly states they are the ones who shaved the bolt.

 

Yeah, if there were something wrong with the bolt, they should have simply replaced it with a correct new one rather than making any modifications to it. The mechanic's story sounds bogus to me.

 

Same here.

What kills me is that these service advisors never know anything technical, they're as bad as a AutoZone cashiers, so the guy was just BSing the entire time I feel like. I wish I could've talked to the tech.

 

Agree with you

 

Can confirm, Locating a knowledgeable Service writer is like finding a unicorn.

 

If I had to guess, maybe the bolt was a little rough on the mating surface and the tech cleaned it up a bit. Shaving would be a weird way to describe that. Also, it would have been better to replace it.

@engineer90 , if it leaks again in the future, I’d be worried that the steel on the actual diff housing has an inclusion right on the mating surface. If that’s the case, that diff will always leak unless it’s taken care of. However, I would like to believe something like that would be visible and not make it through quality assurance at the factory.

If you need to take it in again, have them show you close up focused pictures of the mating surface on the diff. They might try to wear you down by replacing the bolt on the next visit, then replacing the washer on the following, etc. Some places are like that.

 

I hope if there were any real issues with the bolt or the housing threads, they would have chased the threads on the housing as well as replacing the bolt. If the mating surface on the housing was defective, I hope they dealt with it in a sensible way (i.e. not just give it a buzz with the angle grinder).

 

This. What in the fxxx type of shaving had to happen to an OEM bolt? Was the bolt malformed? They have to have a photo of this in the log. They need to replace the now shaven bolt with a fresh OEM bolt & washer. If it continues to leaks, the issue is upstream, not the bolt. No fix should require shaving metal, unless you're at a body shop.

 

Is it possible that floor-jacking the rear up, perhaps right on that bolt by accident, would cause this?

Which wheels are on it? My mind is spinning wondering what the mechanics are like when a vehicle arrives at port. Such a black box. /thinking out loud

 

You place a floor jack under the differential, it is impossible to jack the truck up by the fill plug bolt head.

In terms of inspections at the port....I can not tell you. I highly doubt fluids are checked, especially drivetrain fluids. Body work does occur though from shipping damage. The port installs options and in the case of the TRD PRO, suspension/fender trim/wheels,etc.

The torque on the rear diff fill/drain is only 36 ft/lbs. I wonder how hard you would have to crank the fill plug to break the crush washer?

 

Only when the truck is sitting still….
https://youtu.be/9-yG3D3JBRs?si=u1Ouorrg7vb6V9wS

 

^Splashing isn't going to force oil through a bunch of threads. You need submersion, or internal pressure, which is why I asked @engineer90 to check if his breather is free.