Strange whine from rear

[sh55123]

Hi,

My 325i Sport has recently developed a very strange rear end whine - rather than trying to describe it, I have found a youtube video of a car with exactly the same noise..



Does anybody have any ideas? I am sure it is coincidental, but this noise started after removing my propshaft to replace the guibo and centre bearing. Initially, I thought it was a bad center bearing, so replaced it with another from a different manufacturer, and it still makes exactly the same noise.

Any help greatly appreciated!

[Brianmoooore]

Diff. input bearing is the most common source of a whine on an E30, but it's impossible to tell from a recording coming from a laptop's speakers.

[sh55123]

Hi Brian,

Thanks for the reply. I have three 325i's, and one pf them has what I would describe as a bit of a whiney diff (whines a bit arouund 50-60 mph). The noise coming from the car in question only happens for the first few miles when cold and is very loud. When warm, it and then disappears completely. It is a strange whine (as in the video) that seems to wind up, pause, and then wind up again, even when staying in a single gear. I thought it sounded quite distinctive in the video, and as soon as I stumbled across the video on youtube, I instantly recognised it as being identical to the noise my car is making.

If it were the diff input bearing, would pre-loading the prop centre bearing place more strain/pressure on the diff input bearing and cause it to whine more? Maybe the propshaft centre bearing was not properly pre-loaded before I started working on it?

Thanks again,

Steve