[blackdragon]

ok i havea 8.8 rear end with 3.84 gears in the back. under acceleration the rear end make a low humming then when i get on it a little harder the rear almost howls. i have some power punch im gonna add and check the pinion retaining nut both are tight i just dont wanna tear into it.

[fastpoknee]

Its toast, your axle bearings are toast. does it get quiet in a turn if so its your bearings. and possible your gear and axles are next.

[LTnone]

Were they installed after it rolled off the production line? If gears aren't shimmed properly they'll whine a bit, in which case it's not really harmful but just annoying to listen to. Can be a common problem with gear replacements

[snoel123]

Here's some tips in helping you diagnose this. If it hows under accel and not decel, it means it is howling on the drive side of the gearset. Remove the driveshaft and grab the companion flange (thing that couples your driveshaft t o your pinion) check for play. If there is excessive play dissassembly and inspection is req'd. Mak sure your back wheels are off of the ground and turn the flange. If roughness is felt suspect pinion bearings. NOTE * Usually pinion bearings that are failing or lacking preload will howl on accel and decel but should be checked regardless. If everything is tight and roughness is not felt because it is only doing it on accell it is possible it is gear noise especially if it has been rebuilt not long ago. If you had a failing axle bearing it would not change intensity based on acceleration only pitch because acellerating does not change the load on it. If swerving side to side changes noise suspect axle bearings or diff side bearings. To check side bearing play remove cover and inspect for filings/ damage. Check pinion gears (also refered to as spider gears) and side gears for pitting/broken teeth. Grab differential assly andd attempt to push side to side (towards each wheel). If there is any play The diff will at the very least need to be removed and side bearings inspected/changed/re-shimed. If you have access to a dial indicator record and check backlash/diff ring gear runout before removing. Also note sometimes everything still checks out and a dissassembly may be req'd to find the problem. If the pattern checks out and you still can't find anything wrong i would suggest teardown and inspection. Hope this helps