I used the search feature and could find nothing about my noise. I have a 9 botl with 3:27 ratio. When I am on the gas or hitting the brakes everything sounds fine, no noise's that I can hear, but when I am coasting it sounds like a buzz saw, step on the gas or the brake and noise go's away. I just put the rear in the car, Swapped from a 10 bolt drum to 9 bolt disk. Opened the rear before installing and everything looked good. Fluid was old but no signs of metal shavings. Replaced all bushings with polyurathane bushings. This is a posi rear.

 

Your going to have to check the coast side pattern and pull rearend completly apart to check all of your bearings, just to make sure.
Good luck

 

How do you check the coast pattern ? Any idea how much to have this checked ?

 

RKG, mine was the same way. I put the additive from GM in then drove it for a while and it quit whinning. Was told later that you didn't need the additive if you use synthetic fluid. Good luck

 

Well this noise is more than a whine, you can actually feel it.

 

Mine wasn't that bad. You may need to check that out. There are a few threads on here about these rears. I just pull the axle and take it somewhere. Don't know squat about the inside parts. LOL

 

make sure the pinion bearings are tight enough-if
someone has changed pinion bearings and didn't get
correct "crush"on the crush sleeve or the nut has
worked loose,mesh will be affected during "coast"and
cause the noise.

 

Thanks, Is this the same nut that holds the yoke on. Reading a lot of the post they say to tighten to approx 20 in/lbs that sounds light to me, converted that's approx 1.7 ft/lbs

 

Yes and thats a assembled pinion rotational tq spec.
What it means is they want the pinion/bearings/yoke/seal (without the carrier/ring gear in) to have that much drag/TQ when its rotated with a TQ wrench.
It takes some crush sleeves 3-500lb-ft to crush. then snug the nut a bit and check the rotaional TQ. Repeat as needed.
A factory service manual, a search here or on the net will have good info.

 

DID YOU FIX THIS ISSUE?