Jetsonmobile sound fron rear diff?

[Qyota]

OK, I've had enough - time to get to the bottom of this sound. For about the past 6-8 months, I've been hearing a sound from under the truck, and I'll describe it here:

A) Becomes audible around 20mph and up, and changes pitch with speed.

B) If I shift into neutral while underway, the noise is still there, it doesn't change at all.

C) Sounds like rear diff, but I'm not 100% sure.

D) The sound is like the Jetson's car, only lower pitch, and not so warble-y. I guess you'd call it a whine, but it's not THAT high pitch.

E) The sound is there accelerating or decelerating, and is probably more noticeable while decelerating.

Truck runs great, shifts fine, 4x4 works, etc. I changed the rear diff gear lube about a year ago to some regular 85W-90. Last week I put 85W-145 in it just to see if it would change anything. If anything, it got just a hair louder.
When I removed the drain plug, there was a small collection of fine metal on the magnet, but nothing I'd call terrible. Truck has nearly 160K on it, with original rear end.

Any ideas? Time for a diff overhaul? Am I hearing something else like rear wheel bearings, or transfer case?

Thanks. :ybrick:

 

[Stick Figure]

i would guess wheel bearing from your description, but then its hard to say with out hearing it in person.

 

[the great him]

when going around corners does it get louder? dose it get louder if you have more of a load in the vehicle?

 

[Singtoe]

Sounds like a pinion bearing to me.

 

[PitbullRescuer]

I can almost guarantee it's a pinion bearing. I've had it on my Grand Cherokee and my Yukon Denali. This 4Runner I have now has it a little bit too but it's not terrible, yet.

 

[Qyota]

OK - pinion bearing replacement. What's the procedure?

As far as it being a wheel bearing - noise doesn't change going around corners or with more/less load.

Thanks!!

 

[Qyota]

So, I can live with this for a while? At what point does it become dangerous?

 

[badattitude]

I'm thinking pinion bearing too. The only place in Madison, that I'm aware of, for this repair is Eastside transmission on Stoughton Rd. They fixed mine correctly on the second try. If you know of someplace else in Madison that works on Toyota diffs post it here.

Mine made noise for years, I don't think it ever got dangerous. It did get so annoying I had to do somthing. When I saw the damaged bearing and race I could tell they were bad, but it wasn't like they were on the brink of catistrophic failure.

 

[PitbullRescuer]

It's not really dangerous, but the longer it goes the more possible damage you can have to the differential. It's not a cheap fix though, parts are cheap but labor is pricey. I think I paid almost $1000 to have it repaired in my Denali.

 

[BrettTheThreat]

I was having this exact issue so I took my 98 SR5 into the dealer for an oil change and asked them to diagnose it. They came back to me with pinion bearing too. Still waiting to hear back what the damage will be to the wallet if I go ahead with the repair. The service guy suggested that replacement with a used unit would be the cheapest route. I'll let you know what he comes back to me with.

 

[Qyota]

Thanks Brett, I appreciate it.

 

[JohnsD90]

My pinion bearing was bad, I paid $225 shipped for a used rear diff, the labor to change the bearing would have been much more expensive.

 

[Qyota]

I haven't called around yet, but I'm getting the impression I need to look for a used diff. Mine has the factory e-locker, do I need to find another one of those, or can I use the e-locker on any diff from a 3rd gen?

Basically, which 3rd gen rear diffs are compatible?

Thank you!

 

[the great him]

you are gonna have to use another Elocker diff, just make sure its a match to your current gearing

 

[brian2sun]

Having an elocker complicates the whole diff swap thing, and you won't likely find a replacement elocked diff for less than $500. And since you have an elocker now, you'd probably want to repair it regardless - whether you use it or sell it because they are worth money and in demand.

If it were me, I would remove the rear diff (just mark the slip yoke on the driveshaft so you'll put it back together with the yoke in the same spot). Take the diff in hand to a shop to have them replace the bearing. A decent shop should charge about $250-$300 for labor. A full master bearing kit will cost ~$150. Or you can just replace the pinion bearing and race and that would be a little cheaper. Personally I would do all the bearings for good insurance since they'll have it all apart anyways.

But first, I would confirm with a mechanic that the sound is in fact the pinion bearing. It probably is, but we can't diagnose a sound 100% over the internet. Would suck to spend all that time and money to find out you had a rock caught in your brake drum or something.

 

[BrettTheThreat]

I haven't heard back from the dealer yet, I'll call them this week and see if they learned anything.

 

[Qyota]

Thanks for the vote of confidence, Brian. How difficult is it to remove the diff? Can you run down the procedure for me, including how to mark the yoke? I may do this, after I confirm that the noice is the pinion bearing.

 

[Qyota]

Found a write-up here: How to Remove Rear 3rd Member from Toyota Axle

 

[brian2sun]

Thanks for the vote of confidence, Brian. How difficult is it to remove the diff? Can you run down the procedure for me, including how to mark the yoke? I may do this, after I confirm that the noice is the pinion bearing.

Found a write-up here: How to Remove Rear 3rd Member from Toyota Axle

^^That about covers it. You'll want to mark the slip yoke on both pieces with a Sharpie or something. That way if it comes apart or falls out during the R&R, you'll be able to put it back where it was so the DS stays balanced.

 

[Qyota]

^^That about covers it. You'll want to mark the slip yoke on both pieces with a Sharpie or something. That way if it comes apart or falls out during the R&R, you'll be able to put it back where it was so the DS stays balanced.

Gotcha. Thanks.