I have axles replaced, bearings 3 times, warped rotor and caliper, and now the shops says the differential is bad. Will a bad differential cause this constant grinding noise? I took off the diff cover and changed the fluid. Inside the cover is a magnet and it does have some shavings on it. Not a ton, but enough to look like a little seaonome. Anyway, I would think the gears would cause the sound, but a differential?

Help before I blow money on the wrong thing. How can I check if the differential is shot? What about the gears? Besides measurements, is there a way to torque the tires or something like that?

 

if it were warped t could cause parts failure. my guess is the shop is looking for the quick easy way out and wants to replace everything.

 

What kind of noise is it? Did they replace ALL of the bearings? Does the noice happen only on acceleration, decelleration or is it all the time? Hard to believe it's the differential. If it's a grinding noise only going around corners then the spider gears could be eaten up, but those are replaceable and cheaper than a new diff. Whining or howling on acceleration or decelleration would point to the ring/pinion being worn or the backlash too tight. Whining all the time would be a worn bearing.

 

It's all the time, starts at about 20-25mph actually. Also my right rear tire is going bald. I believe it is the differential if only one tire is smoking on hard launches, right? Both tires do spin, if I hold the brakes down and let 'er go. But most of the time it's the right rear that spins. I do have a posi rear. Both bearings were replaced 3 times. The right axle was replaced as well. I'm about to say F-it, and buy a 4th gen rear, but I lack the money for it, as well as the adaptors for the wheels.

 

Sounds like you have two different problems. If you only had the outer axle bearings replaced then you still have 4 old bearings inside the rear and the noise is most likely coming from one of them. The one tire spinning is because you either have an open differential or the clutches in your diff are worn out meaning you need to replace or rebuild it.

 

It's a posi. I've seen it. Where are the inner bearings?

 

You've got an inner and outer pinion bearing and a bearing on each side of the carrier.

 

Now I am under the influence that my Auburn posi is NOT rebuildable. Is that true? The rear is from an '89 Iroc I believe. I have the PBR calipers on it.

Now the shop did say there was excessive wear on the teeth, something about 4 human hairs width of movement (or whatever the terminology is for that) when there should only be 1 human hair width of allowable movement. That is all I know. They said to bring it to a rear end shop.

 

I guess they mean the backlash is too much. That is a measurement of the clearance between the pinion and ring gear. I don't know what he means by "hairs", but I like to measure it in thousandths of an inch . I set them up so the backlash is between .007 and .012". If the gears are worn too much or are wearing in the wrong spot resulting in excessive backlash, then that is part of your problem.

No, your Auburn is not rebuildable. Sorry, you hadn't mentioned which type you had.

 

What a nightmare.....So basically, a whole new rear end would be cheaper, right? Someone said I can buy their's for $300. But it's a 3.23, whereas mine is 3.42. I hate spending money and stepping down.