Center Support Bearing

What the hell does this look like?

It's a bearing that supports the middle of your 2 piece drive shaft. Without it it would flop around like a limp noodle.

Cheers

That would be the bearing that supports the center of the driveshaft. When it fails, you first notice a vibration when you drive off.

Your drive shaft is built in two pieces. The forward piece is attached to the back of the transmission, the rear piece is attached to the differential (rear axle). The two sections of drive shaft come together at the Center Bearing, or Center Support. The center support is easy to find when the car is on a lift. It is probably hiding behind the exhaust system and a heat shield, but once you locate the drive shaft, the center support is easy to find.

While you're in there replacing the center bearing, take a look at your guibo (flex disc) as that will probably need replacing too.

Thank you all for your responses. A BMW service center quoted me $330.00 incl labor to fix it. will surprise him with that bit of information below before i go and get another quote for that work.

Jeff Strickland wrote: > That would be the bearing that supports the center of the drive shaft. When > it fails, you first notice a vibration when you drive off. >

However, that does not mean that every vibration that occurs in this area is due to a bad center support bearing. Any imbalance or worn joints in the drive shaft will cause these same symptoms, even the oft' maligned guibo can cause it. Make sure a thorough inspection has been done and make sure the mechanic doing the work is thoroughly familiar with BMW drive shafts or you could be in a for a rude ($$$) awakening.

When the drive shaft is disassembled to replace the bearing it must be match marked before hand so it can be reassembled in the exact same orientation or you *will* have even more vibration than you have now.

A PO of my '94 E34 must have had some drive shaft work some as the car had a new guibo and what looked like a recent shaft installed. I had your exact symptoms even though every part was solid.

It took a new BMW drive shaft at the tune of ~$1000 to sort this problem out.

Good Luck,

-Fred W

It's very close to the muffler bearing - and the failure gives the same symptoms.

If it goes really bad the driveshaft will reach out of the driveshaft tunnel and smack you upside your head - which might not be a bad thing.

Have you given ANY thought to looking for a manual for your 735? It might answer some of the questions you're deluging this newsgroup with, and give you information when you go to a mechanic.

Rev. Don Esq, ULC No Latin sig here.

You mean like this one:

In the past did not have the time to delve into the inner workings of my

735i. This group has been my foot in the door. Hopefully thats what this group is for. If not, someone let me know what alt.autos.bmw newsgroup is all about.

Be advised, it's all the same work.

The flex disk is a rubber contraption that holds the drive shaft to the back of the transmission, there are 8 screws in it. 4 screws hold the drive shaft to the disk, and 4 hold the disk to the transmission. The time to replace the disk AFTER the the drive shaft is down is about 2 minutes.

Thanks Jeff. will make sure that work will be included in the labor for the Support Bearing. since 2 mins. is nothing for that flex disc.

Just be sure they don't quote you several hours for the job that is 99.9% done anyway.

If they were only going after the flex disk, then I am not sure, but I think the hour estimation is in the range of 2 hours, give or take a little. Basically whatever the hours are for the center bearing will be the same for the flex disk, but when going after the center bearing, the flex disk is exposed anyway.

Like I said earlier, the flex disk has 8 bolts, 4 that hold the drive shaft to it and have to come off to gain access to the center bearing, and 4 that hold the disk to the butt end of the transmission. So, when going after the center support anyway, there are only 4 more bolts to get the the disk out. How long can it take to remove 4 more bolts? 2 minutes?

Fair enough. However, if you want to become more "educated" about your car, you may want to check out the online BMW ETK (parts) catalog to get the part numbers and see what is needed to repair your car:

Good Deal I will get right on it.