Rear diff whine?

[DMILLA33]

Alright I've posted about this before but I'm really trying to narrow it down...
Previously I was told this was a wheel bearing but it can't be
When I'm driving around 25-30 mph and I shift into 3rd I get a whining noise that has to be coming from the diff
After I get higher into 3rd I wont hear the noise until 70 mph in 5th or 6th gear (a few months ago the noise was only at 65, now it went to 70?)
This goes away whenever I let off the throttle and I have no upgraded diff mounts that would cause this!
What are the signs of a bad diff?
Thanks in advance!

[KaiPLN]

Mine always whines in 3rd.

[DMILLA33]

http://www.youtube.com/watch?v=0CK8zAAw4AA
Does it sound like this??^
Also I changed my rear diff fluid with motul 300 like 6 months ago... the axle seals on the passenger side are leaking a little bit but I doubt thats my problem

[sherbet]

Could be the mount.

When I upgraded to the Apikol rear diff mount, I started to get a lot of this type of noise. Its there around 30-40 and at 65-75. Gets pretty noisy right at about 70.

[DMILLA33]

Could be the mount.

When I upgraded to the Apikol rear diff mount, I started to get a lot of this type of noise. Its there around 30-40 and at 65-75. Gets pretty noisy right at about 70.

I do not have the upgraded mount tho! I'll double check but I'm almost positive that its stock! unless you can put just stiffer poly bushings in there??

[sherbet]

Im saying your stocker could be worn out. Just a guess. I've seen people fill the stock diff mount with epoxy....

[DMILLA33]

Im saying your stocker could be worn out. Just a guess. I've seen people fill the stock diff mount with epoxy....

Well an apikkol diff mount is on my list of upgrades so maybe I'll get one sooner!

[EuroxS4]

apikol mounts are known to make those type of noises even worse then they are.

Please check this link from a while ago:

http://www.audizine.com/forum/showth...Need-some-Help!!

[sherbet]

Well an apikkol diff mount is on my list of upgrades so maybe I'll get one sooner!

If you want the noise to go away the best thing to do is get a new stock mount. (assuming the mount is causing your problem) The Apikol will holler at you likely worse than whats in there.

[EuroxS4]

agreed!!

If you want the noise to go away the best thing to do is get a new stock mount. (assuming the mount is causing your problem) The Apikol will holler at you likely worse than whats in there.

[DMILLA33]

apikol mounts are known to make those type of noises even worse then they are.

Please check this link from a while ago:

http://www.audizine.com/forum/showth...Need-some-Help!!

So your replacement diff is still good with zero noises?? Will the diff I have now just keep getting worse till something breaks in it? and how much of a bitch is it to put in a new one? I've had my motor out multiple times so I have experience wrenching!

[EuroxS4]

the diff I have in it now is still good no issues or noise.I got the diff with 30k miles on it.All i did was replaced the axle seals before i swapped over the axle flanges and put new oem fluid in it.replacement is not bad.Much easier if you have a lift.You have to drop the exhaust.Other than that you dont have to remove anything else.Thats how I did mine.As mentioned in my old thread.Just make sure you diff you get have the same final drive ratio otherwise youll damage the torsen diff.

If you keep the diff you have the noise will just get louder or more noticeable with time.I dont think anything will break because the cause of the problem is radial play of the pinion gear bearing.I replaced mine cause it was annoying as hell at highway speeds and got progressively louder over time.

The noise in my car was most noticeable while coasting at highway speeds 55-80mph and under part/light throttle.I lowered the rear seats the the noise was louder with seats down.

[DMILLA33]

the diff I have in it now is still good no issues or noise.I got the diff with 30k miles on it.All i did was replaced the axle seals before i swapped over the axle flanges and put new oem fluid in it.replacement is not bad.Much easier if you have a lift.You have to drop the exhaust.Other than that you dont have to remove anything else.Thats how I did mine.As mentioned in my old thread.Just make sure you diff you get have the same final drive ratio otherwise youll damage the torsen diff.

If you keep the diff you have the noise will just get louder or more noticeable with time.I dont think anything will break because the cause of the problem is radial play of the pinion gear bearing.I replaced mine cause it was annoying as hell at highway speeds and got progressively louder over time.

The noise in my car was most noticeable while coasting at highway speeds 55-80mph and under part/light throttle.I lowered the rear seats the the noise was louder with seats down.

Alright well I'll just keep it till I start getting annoyed! lol
mine is pretty quiet for now and when it snows or rains or when my music is up, I cant hear a thing but thanks alot for the help man!

[dub914]

Have you simply tried to jack up both rear wheels and rotate by hand to hear if you have a bad wheel bearing?

I replaced my diff thinking it was bad, and sure enough it was a wheel bearing. Also recently had a wheel bearing only last 3 month. So never assume its not the wheel bearings.

[DMILLA33]

Have you simply tried to jack up both rear wheels and rotate by hand to hear if you have a bad wheel bearing?

I replaced my diff thinking it was bad, and sure enough it was a wheel bearing. Also recently had a wheel bearing only last 3 month. So never assume its not the wheel bearings.

Did your wheel bearings sound identical to the video I posted above?? cause thats the exact noise and I've checked my wheel bearings and they seem fine

[erikc17]

When I'm driving around 25-30 mph and I shift into 3rd I get a whining noise that has to be coming from the diff
After I get higher into 3rd I wont hear the noise until 70 mph in 5th or 6th gear (a few months ago the noise was only at 65, now it went to 70?)
This goes away whenever I let off the throttle and I have no upgraded diff mounts that would cause this!

Does this noise happen to you at all when you are coasting in neutral at those speeds? (if you ever do that)

[ilyafil]

Check your diff. oil first, they usually whine when low on oil.

[DMILLA33]

Does this noise happen to you at all when you are coasting in neutral at those speeds? (if you ever do that)

Nope! it only does it under load

[DMILLA33]

Check your diff. oil first, they usually whine when low on oil.

how will I check my oil? just pull out the fill plug and pump in some more and if it drips out then its full, correct?

[EuroxS4]

the drain is on the bottom of the rear diff the fill is on the side.From what I remember if the fluid is coming out of the lower lip of the fill your at the right level.the rear diff takes 1.9liters of fluid.

[DMILLA33]

the drain is on the bottom of the rear diff the fill is on the side.From what I remember if the fluid is coming out of the lower lip of the fill your at the right level.the rear diff takes 1.9liters of fluid.

Yeah I did this 5 or 6 months ago and I filled it to that with motul 300 and I let it pour out of the fill till it stopped and I did that multiple times because I was paranoid so I'm positive my fluid is not low!

[sherbet]

It seriously sounds like the mount. I doubt its related to fluid level.