Rear Axle Differential/Center Bearing Whine Noise

After doing some research on this damn annoying whining noise that usually happens when you apply just little bits of pressure to the accelerator at all speeds and RPMs in my case, I’ve decide to try to fix this myself. It appears that there are a lot of us out there with this problem, and since I like many, am out of warrantee, I don’t feel like spending a whole bunch of money on 5 inch piece of Butyl tape plus I’m always up for a good DIY…

See figure
Number 10

http://www.realoem.com/bmw/showparts...97&hg=26&fg=10

So the statement below from BMW…….

SITUATION
A loud whine or howling noise may be heard in the compartment at
approximately 70 miles per hour with a light engine load.

CAUSE
The meshing of gears in the rear axle differential generates a whine
noise under the conditions described above which on some vehicles may be
transmitted to the body via the drive shaft center bearing.

CORRECTION
On a customer complaint basis only install a drive shaft center bearing
insulation strip(butyl strip) BMW part # 26 12 7 511 140 to reduce the
drive
line noise which is transmitted to the vehicle body as outlined below.

Defect code 33 10 90 39 00

Now after looking for this center bearing it appears to be under the exhaust heat shield, damn.. Not that easy to get to. I think I can manage to get it mostly off enough to get to the bearing, but am afraid of actually loosing up the center bearing bolts (i.e preload and such problems) to get the tape in there on tope of the bearing casing. After talking with some guys at the stealership, they claim that they remove the heat shield, and then very carefully lower the center bearing just enough to wedge in some of the tape.

So the whole idea is to insulate between the casing and chassis right, well I was thinking of buying some butyl goo-in-a-tube and just shoot a whole load up in there with out lowering the bearing. You can find this stuff all over the place and I would assume it’s probably the same as the tape just in a different form. What do you guys think? The only thing I worried about is the curing time, and if it’ll hold up and not just fall off after time. Anyone ever tried it before, what are your thoughts????

Thanks

Are you sure it is driveshaft related? Wheel bearing noises can be deceptive. FWIW, I'v changed a handful of E46 front and rear wheel bearings on cars with less than 100k miles.

Mine has a clunk whenever load is applied to the drive-train. Like when I step on or back off the gas pedal.
It's like there's too much slack in the drive-train. Any ideas, cus I'm also out of warranty?
I did take it to 2 independent shops and they both didn't know.
Can you recommend a good shop in N. jersey teamdfl?


-Rich

Originally Posted by teamdfl

Are you sure it is driveshaft related? Wheel bearing noises can be deceptive. FWIW, I'v changed a handful of E46 front and rear wheel bearings on cars with less than 100k miles.

I'm pretty (99%) sure its not the wheel bearings, because the whining sound is dependent on throttle position.

Originally Posted by SrCsTc

Mine has a clunk whenever load is applied to the drive-train. Like when I step on or back off the gas pedal.
It's like there's too much slack in the drive-train. Any ideas, cus I'm also out of warranty?
I did take it to 2 independent shops and they both didn't know.
Can you recommend a good shop in N. jersey teamdfl?
-Rich

That clunk is pretty common issue in some E46s, it is due to a bad differential mount. You could jack it up and inspect for any cracks or abnormalities. If it's bad you'll have to press out the bushing which requires one to drop the differential. Not that bad really, pretty easy to get too Here's a DIY thread:

http://forum.e46fanatics.com/showthr...light=diff+diy

Originally Posted by JmAbshire

That clunk is pretty common issue in some E46s, it is due to a bad differential mount. You could jack it up and inspect for any cracks or abnormalities. If it's bad you'll have to press out the bushing which requires one to drop the differential. Not that bad really, pretty easy to get too Here's a DIY thread:

http://forum.e46fanatics.com/showthr...light=diff+diy

When I took it in to have the clunk diagnosed, I had all the diff bushings replaced (3 I believe). As well as the guibo. It apears to be too much slack somewhere between the diff and the trans. Maybe one of the flanges?


-Rich

Originally Posted by SrCsTc

When I took it in to have the clunk diagnosed, I had all the diff bushings replaced (3 I believe). As well as the guibo. It apears to be too much slack somewhere between the diff and the trans. Maybe one of the flanges?


-Rich

Bad driveshaft center bearing? The shop should have doen a preventative replacement while they were in there doing the guibo because the required labor is almost identical and the center bearings seem to have a lifespan similar to the typical guibo.

For a good independent shop, try Freedman Tire (Edison) or Motor Works West (Wyckoff). I'm sure there are others but these are the only two I have personal experience with.

Center bearing inspection is not difficult if you can put the car up on jack stands. I have even done driveshaft replacement on a gravel driveway.

Originally Posted by SrCsTc

When I took it in to have the clunk diagnosed, I had all the diff bushings replaced (3 I believe). As well as the guibo. It apears to be too much slack somewhere between the diff and the trans. Maybe one of the flanges?
-Rich

Yea, then I would guess the next thing would be the alignment on your drive shaft and possible slack, maybe that center bearing support needs adjusting??

Originally Posted by teamdfl

Bad driveshaft center bearing? The shop should have doen a preventative replacement while they were in there doing the guibo because the required labor is almost identical and the center bearings seem to have a lifespan similar to the typical guibo.

For a good independent shop, try Freedman Tire (Edison) or Motor Works West (Wyckoff). I'm sure there are others but these are the only two I have personal experience with.

Center bearing inspection is not difficult if you can put the car up on jack stands. I have even done driveshaft replacement on a gravel driveway.

What am I looking for on the Center bearing?


Rich

Originally Posted by SrCsTc

What am I looking for on the Center bearing?


Rich

Look for a deteriorated rubber surround. The bearing itself can also go bad but I usually see the rubber surrounding part dry rot or crack before the bearing itself makes noise.

The shop that did your guibo really farked you by not replacing the $40 center bearing at the same time. I replace both whenever I have to do one or the other on any of my BMWs.