Haven't been on here for awhile. My last posts regarded a front diff howl. I've been putting up with this for quite a long time since I spent a lot of money replacing wheel bearings, cv axles, etc. with no result.
Yesterday I raised the rear end off the ground, put the trans(auto) in neutral and spun the rear tires by hand. There is a clicking/ticking noise coming I believe from the rear diff. This could have been the problem the whole time coming from the rear and transmitting up the drive line to the front. It really sounds like the problem. Since the driveshaft wasn't turning during my spinning the wheels, do I have a spider gear problem? The noise is the same intensity at either rear wheel when spinning. When going down the road the howl is loudest at 40mph but is still there at 65mph(higher pitch). It is there accelerating or decelerating. When at 10 mph feels like you are on a rumble strip. The rear diff housing is dry as a bone on the outside and no leaking from axle seals. I have not checked the fluid level since there's no sign of leaking. Any suggestions?

 

i admit i'm not a good mechanic but i can keep my truck running without more than occasional help from a real mechanic. if it were my truck and i was reasonably sure it was the differential, i'd buy a rebuilt one already assembled with the ARB air locker I've been wanting and swap that in and try it. of course if you already have an ARB then it's worth it to troubleshoot the problem (but if you installed the ARB into a rebuilt diff in the first place then it's probably not the problem).

this may not be the advice you were looking for, but is an option to consider. my toyota is my daily driver so i usually need to fix it fast so i can get to work and shops where i live are more expensive than OEM parts. your situation may be different.

 

This is my DD also. I do not have a locker and don't off road. I guess I'm looking for a rear end specialist to try and narrow this down.

 

As a quick diagnostic stepp, you might drain the oil and look for shiny stuff. Then refill with new oil (of course).

If turning both wheels (and keeping the other still) results in a similar amount of noise, it's unlikely to be a wheel bearing. The odds of two of them getting evenly worn out at the same time are tiny.

 

I will try draining the fluid tomorrow and update..thanks

 

Some level of ticking noise is normal due to spider gears. Source of whining easy to identify - put the truck up on 4 jack stands, run it at 35mph and get under to listen for location of noise. Use mechanic stethescope. Careful to make sure truck is secure on stands and watch out to not get tangled up in the rotating driveshaft. Although my noise was clearly coming from the rear, I used this technique to verify rear diff pinion bearing noise prior to rebuild vs diff ring gear, side bearings or axle bearings.

Buckaroo

 

I'm going into town to get a 24mm wrench for the fill plug and I'll pick up a stethoscope at the same time. Thanks