Rear bearing or prop shaft bearing ?

Post Tue Feb 05, 2013 6:32 pm

Hi,

I have a whining noise and I don't know if it's one or both of the rear bearings or the prop shaft bearing. Is there any way of trying to narrow it down ??
Car is a 325 cab, 1986, with 104 thousand km. I presume none of these parts were replaced by the previous owner (I've had the car 12 years).
When driving up to 30/40 kmh there is nearly no noise ... but after this it starts whining - motorway speeds is just annoying. First signs started a couple of years ago but it has been getting progressively worse.
I presume it is not possible to have the car moving with the rear wheels turning and the prop shaft still ... ??

Have changed the gearbox oil to rule that out but it really is quite difficult to localise the noise to the rear or closer to the prop shaft tunnel ... I even thought at one point that it could have been the front wheel bearings.

Hope you clever heads can maybe point me in the right direction ...
Regards,
G

Post Wed Feb 06, 2013 4:20 pm

I'm watching this as I have a similar issue. I'd thought it might also be the diff. Awaiting the wisdom of the zone

Post Wed Feb 20, 2013 7:08 pm

Bump ....

Does no one on here know a way to narrow things down ??

Now it sounds like it coming from the front ... again.

I guess new front bearings is the easiest thing to change ......
Then the prop shaft bearing (and install a new gearstick) ... reaer bearings last ??

Hope someone can answer ....

G

Post Wed Feb 20, 2013 7:10 pm

Is it a whine or more of a vibration ? .

Post Wed Feb 20, 2013 7:35 pm

A whine ... no vibration at all.

G

Post Wed Feb 20, 2013 10:49 pm

if there is no vibration you can most likely rule out the prop shaft bearing \ rubber donut as these cause a vibration and can cause a tumping noise under the car under hard accleration.

A rear whine usually points to the diff.

Post Thu Feb 21, 2013 8:15 pm

Thanks,
But what are the signs of a prop shaft bearing in need of replacement ??
I have experienced the knocking of a duff donut .....

G

Post Thu Feb 21, 2013 9:24 pm

The bearing is usually very similar symptoms as the donut failing. Most prominent under hard accleration. Also constant vibration when cruising at speed.

Post Fri Feb 22, 2013 6:46 pm

Thank you for your replies.

I'll strike the prop shaft off the list for now.
Guess it will be the front bearings to change first and then hope that the rears don't need doing.
Slightly hoped it was the prop as at some stage I'd like to fit the Z4 gearstick (as I had in my touring) .......

G

Post Fri Feb 22, 2013 7:12 pm

Jack the car up and spin each wheel and check for play. There might be a little side to side movement in the fronts due to ball joints and top mounts, but the rears should be pretty much solid. When you spin the wheel there should be no rumbling. Knackered bearings rumble.

Sounds very much like the diff or gearbox. No point wasting your money on bearings when it doesn't need them.