Differential whine

[naplesE30]

Hi everyone I just bought a 91 318 iS a few days ago. The car is pretty clean and only has 74k on it. However, there are a few minor probs with it. The most serious being when moving there is a whine that sounds like it is comming from the diff of the car. Faster I go the higher the whine. Rear wheel bearings seem to be ok as there is no play in the wheels. Drained the oil from the diff and it was clean,,, no metal. I think it could be the pinion seal or possibly the bearings in the diff. Has anyone had a similar prob? or replaced the seal... I cant wait to straighten this prob out so I can begin some projects I have in mind for this car. Thanks for the help.

[nicknikolovski]

Sounds like you may have worn Pinion Shaft Outer Bearings. These parts are fairly cheap, but if you're going to do these bearings you might as well do the Pinion Shaft Inner Bearings as well. You may like to get a differential specialist to help you out because replacing differential parts can be a challenge. Also it can't be a pinion seal because they only prevent diff oil from coming out. If the differential is leaking oil then you should replace the relevant seals. Also you may have to replace some seals in order to replace the worn bearings because I don't think you can reuse old seals.

Hope this info helps.

Here are the part #'s from Pelican Parts

Pinion Shaft Outer Bearing - (33-12-1-468-895-M92) - $17.25 each
Pinion Shaft Inner Bearing - (33-12-1-468-894-M92) - $16.75 each

Both these items are superceded parts.

[naplesE30]

Thanks for the info. I just bought the bearings and seals from P.P and will let you know how I fared. Once this prob is solved I should have all the mechanical kinks worked out. Next up suspension upgrades:D

[nicknikolovski]

No worries dude any time, let me know how you go.