Rear diff whine?

[bloodshot-e30]

alright my 3.73s are whining im wondering what would be making it happen? bearing or the acctual pinion gears? and is it gonna grenade on a long trip?

-Josh-

[Jaxx_]

what fluid do you have in it?

[5Toes]

Thanks for reminding me of this... I believe my diff is starting to whine too... but it is weird because when my auto changes gear the whine gets softer... I would figure that the whine would stay the same because the car is moving the same speed, if not a little faster

[bloodshot-e30]

^ that might be tranny...


and i have 75-90w what ive always used in all my diffs with the LSD oil.

[Wh33lhop]

My diff has always whined. It's pretty loud now, but I've given it about 40 thousand miles of hell and it's been fine functionally. IIRC it's the output bearings that typically cause this, and it really only happens with LSDs. Most open diffs are fine.

[Texas Toast]

Positive its not wheel bearings?

[iamsam]

Usually bearings. Sometimes incorrect gear lash. Change output bearings and see if it goes away. If not, pull the lsd out, change input bearing, and a new crush bushing and re-set gear lash.

[bloodshot-e30]

My diff has always whined. It's pretty loud now, but I've given it about 40 thousand miles of hell and it's been fine functionally. IIRC it's the output bearings that typically cause this, and it really only happens with LSDs. Most open diffs are fine.

gotcha!

Positive its not wheel bearings?

yea those are new ;)

Usually bearings. Sometimes incorrect gear lash. Change output bearings and see if it goes away. If not, pull the lsd out, change input bearing, and a new crush bushing and re-set gear lash.

awsome ill check it out thanx!

[Pantless Spency]

in my e21 my diff makes horrible noises that no human would enjoy.....
think loud banging squeaking and grinding. i still gotta jack it up and check her out ;) haha

[tjmonsen5]

my buddies diff is SOOO LOUD. Its louder than his straight pipe exhaust, its terrible.

So you can buy a new bearing for it instead of replacing the entire thing? Enlighten me on where to find these bearings.

[Cabriolet]

miles on the diff? the clutch pack might be shot.

[bloodshot-e30]

nah clutches are still good it started to whine when it was in my 318is so im guessing its maybe 150k on it?

[Jaxx_]

miles on the diff? the clutch pack might be shot.

I don't see this being an issue in a straight line.

[SoloSol]

Mine is noisy too, still has plenty of grab. Ive switched out Motul and put in Redline. No change. You think its loud now? Dont take out the back seat.

[Holland]

Lol, the less sound deadening you have the louder it will be, same with poly subframe bushings, it will reverberate through the chassis.

Worn pinion bearings are usually the cause of whiny diffs, but if you are going to go to the trouble of replacing them then consider fresh clutches, even if yours do work they more than likely don't have as much grab as they used to.