How do I quiet a noisy front differential???
 

Just got a 98 subaru forester with very noisy differential. Found out it was ATF in the differential:eek:. Put in the correct 80W90 gear oil lube in and its still very noisy.
What can I do to quiet it down? The car drives nice and I dont want to replace the whole transmission if its not broken.
Any suggestions?
Thanks in advance

Noise tends to be precursor to failure, sorry.
-Bill
p.s. keep an eye on the fluid in the diff to see if ATF doesn't show back up. If it does, you've got a trans-diff seal issue.

You may well have, probably do have, a damaged bearing that is making the noise.

This will just get worse and worse until it breaks, or until it is so noisy you have to get it replaced.

Making it quiet is only a short term solution, you really need to get it fixed.

Having said that you may be able to keep it from getting worse for a short while by adding a modifier to the oil. One I could suggest is Molyslip ATFA. It should not hurt to try a tube of this stuff. If it does not work, then plan on replacing the bearing.

http://www.molyslip.com/Products/MolySlipATFA.html

CAUTION: Do not use Molyslip friction modifier for manual gearboxes in your differential. This will cause the LSD to stop working because of no friction. Only use the one mentioned above.

Also please note you act on the above advice at your own risk. The correct thing to do is replace the noisy bearing. Best of luck with it.

Joe

I'd bet someone did a flush and added ATF instead of the proper oil, probably at one of those speedy-lube type places where there's one person under the car and one over. I've been asked what Subies take in the front diffs and get funny looks when I don't say ATF.