Whiny b!tch

[ParsedOut]

Just picked up an 87 325e and above 35mph there is a pretty high pitched whine coming from the rear (it seems). It's speed related. The driveshaft feels good, no vibrations. I've had CSBs go out on me in the past they usually rattle and vibrate.

I've noticed generally when bearings go out they get loud and "ROARY" instead of whiny. This noise sounds very much like a gear whine.

Has anyone noticed a rear wheel bearing, half shaft, CSB make a whine instead of rumble? So any idea what I should be focusing on here? Rear diff seems to be the mostly likely culprit.

[series88]

I vote diff. :)

[andrewm]

Diff.

[ParsedOut]

Hmm... well time to find a 2.93 laying around.

Thanks guys.

[jlevie]

Differential or wheel bearing. Until diagnosed either is equally likely.

[e30saam]

Try and find a 3.25 diff from an e28, just replace the diff cover with an e30 one, this will wake your eta up. They are the perfect diff ratio for etas.

[ParsedOut]

Differential or wheel bearing. Until diagnosed either is equally likely.

I've never had a wheel bearing make a whine, usually they growl. Have you experienced otherwise? Other than just replacing parts, what would be the best way to diagnose?

Try and find a 3.25 diff from an e28, just replace the diff cover with an e30 one, this will wake your eta up. They are the perfect diff ratio for etas.

I spend 90% of my time on the freeway commuting, although a slightly shorter gear ratio sounds nice. :)

[e30saam]

I spend 90% of my time on the freeway commuting, although a slightly shorter gear ratio sounds nice. :)

Yeah I drove a buddies eta with a 3.25, it was a lot of fun around town though. But my eta with a 2.79 LSD revs a bit lower on the highway.

[ikonwun]

PM.d you man. sorry to hear that this one is taking a lot of work too.

oh yah it sounds like a rear diff.