Resolved: Troubleshooting rear end noise

EDIT Resolved - The what appears to be common problem of the wrong differential fluid in these LSD's. Refill with the proper fluid problem totally resolved

One thing I learned is that it is an easy mistake when n some cases even though it is indicated on the differential. The parts store that my shop uses used my VIN to look up the correct fluid. The problem is that on my 18-year-old truck the Toyota database did not include the fact that I have a limited slip differential



Orig:

I recently had a complete front and rear brake job, and the differential oil changed.

the very next day, when I was backing out of my driveway and applied the brakes, there was a rumble and you could feel a slight vibration or shake. I don’t notice it as badly now when backing up and applying the brakes, but it also happens when I’m at a stop and then make a turn

this only happens at low speeds. The shop checked everything but not find any issues They were hoping it was just the brakes, and it would go away, but it has not. I’ve been worried it was in the differential, but from what I read, if there is an issue with a differential, it won’t just be at low speeds

reading through some other threads, I see where the rear brakes have to be adjusted manually by engaging and releasing the park brake four or five times. I don’t believe this corrected it, although I repeated it, and I’m about to test it again

the problem is it doesn’t do it every time

 

That is the classic sign of chatter. Do you have LSD rear? If so, they used the wrong fluid in the rear.

Been there, done that, chose not to listen about how picky the LSD rears are in these trucks. Don't let the shop put in additive. Trust me on that. I tried. 5-6 oz later, and I was still slightly chattering. Just have them replace with Lucas 80w90.

 

How can I determine if I have LSD? I’ve got my original sticker around somewhere, but when I moved, it has been misplaced

Is there somewhere I can just key in my VIN?

 

https://www.tundras.com/threads/rear-diff-gear-oil-for-lsd.131247/#post-3339970

The warning is right in front of your face before changing the fluid. Anyone changing the fluid should have a hard time missing. Unless your rear diff is rusted, or someone peeled it off for some unknown reason, should be there, if applicable.

 

This thread also covers diff fluids.

It also covers how to sign up for Toyota Owner's site which will sometimes give you options info, including LSD (but not always)

https://www.tundras.com/threads/so-you-wanna-buy-just-bought-a-1st-gen-tundra-eh.115928/

Can't recommend enough, taking the time to read it.

 

Then that begs the question what if it is not a limited slip differential. Could that still be a problem With the wrong oil?

and I have read that entire post, although perhaps not the entire thread. it is a lot to absorb and I probably need to reread it a few times to get it through my thick head

 

I had created that account or reinitiated it, because I believe I did it years ago

I could not find much information, but I just went and looked again and found more details. I don’t see any mention of a limited slip differential. However, it is wrong about the wheels and tires that came on my tundra because I have P265/65R17’s

 

Yeah, the Toyota Owner's site has become notoriously inaccurate in last couple of years.

I mean, a photo through the fill hole (upper bolt) could help us tell you whether it's LSD or not. You may need to take a pic while holding a flashlight over the hole. Be prepared for a little drippage, but it's nothing you need to replace, fluid-wise.

But a 'skipping' sensation at low speed while the wheel is cocked even the slightest, especially when backing out of a parking spot, turning right from a stop sign, that kind of thing - turning from a stop - that's what chatter feels like.

 

I suppose it's feasible the rear brakes were adjusted a little bit too tight.

 

But it’s not likely to be the wrong oil used in the rear if it is not limited slip?

 

OK, thanks I missed this reply before I replied earlier. I will dig into this the next day or two as I have time. Thanks again shifty

 

LSD chatter is caused by the clutch plates used in an LSD rear end skating/skipping against each other. If you don't have LSD rear, you won't have clutch plates, so there should be no skipping to be had, it's pure gearing.

With the pic I requested through the fill hole, we should be able to tell you whether you've got an LSD in there, it's info you'll probably want to have, similar to this guy, who I believe was also lacking his sticker but gave a pic thru the fill hole and it was determined he had an LSD rear. But there are some other options to check if you're uncomfortable removing a single fill plug that'd relatively zero-risk...

 

If I understand correctly either pull the plug or use a hydraulic floor jack to lift up both wheels off the ground.

Where is a safe contact point for the rear to raise both wheels off the ground?

Also, now that I’ve had time to think about this a little bit it absolutely has the sensation of two clutch plates slipping, or rubbing against each other

 

That info is in your owners manual I think but here : https://www.tundras.com/threads/first-gen-jack-points-from-fsm-om-and-maybe-others.124063/

If you have a floor jack, directly under the pumpkin is fine for lifting both wheels.

 

Turns out all of that is unnecessary.

mine does plainly have the LSD sticker/tag.

shop is checking to be sure correct oil was ordered but it sounds like they don’t need to bother because it had to be the wrong oil, since it started immediately after the change

 

What is there to order? Lucas 80w90 or Motul 90pa are ideal. This is a known issue with the LSD Toyota put in these 1st gen trucks.

The shop f'ed up. They probably used synthetic. This is why I don't trust people to work on my vehicles.

How aggravating. Don't let them bullshit you. They should've known about this, the sticker is literally RIGHT THERE on the diff where you can't miss it while filling up. There is absolutely no excuse for the mistake except ignorance.

 

They use a parts house next door to their shop.

The owner of the shop researched what happened thoroughly. They are very reputable The mechanic took the VIN and gave it to the parts house. First, the parts House said they didn’t sell any on that day. so the shop dug through all of his invoices because they save everything and found out they did in fact, sell them the wrong oil

that will be my next stop for them to drain it and fill with correct oil.

Thanks shifty and all.

I guess one last question. Is simply draining and replacing enough or does it need to be flushed?

 

Drain and fill is fine.

 

Outstanding. You are a walking encyclopedia for tundras

i’m trying to research the forums as best I can, and avoid so many posts. But it often returns so many responses and most are unrelated.

 

I know what you mean, and now I’m going to be doing more and more repairs myself, or checking in on the Work to inspect

The shop I am using now is very reputable and has always been good to me. But they don’t specialize in Toyotas.

at my previous shop, they worked mostly on Japanese imports, and the owner personally had Toyotas and tundras for years so he was always extremely knowledgeable and insightful. However, he has gotten older and tends to like to let things go so the symptoms are easier to diagnose. it was becoming infuriating. It just got so annoying that I quit using him plus when I retired 2 years back his shop is no longer close by

 

Follow up: differential oil changed and replaced with the correct oil.

All related issues are gone

 

Amazing how quickly it resolves eh. I know you'd expect some residual something-or-other, but it's just a matter of getting the pack rolling a few times thru compatible fluid.

Ah well, lesson learned, hopefully for you and the shop