Driveshaft center support bearing replacement ???'s

[DigDug]

Hi all...

I'm in the process of trying to replace the center support bearing on my 1987 BMW 325 (base), auto trans. Man those bolts are tight!!!

My I've got access to the driveshaft and have gotten the front u-joint bolts (on the transmission side) loose (I was surprised there is no flex-disk, guibo, on this car), but the ones on the back end are TIGHT!!!! bloody knuckles, cussing, etc, won't help.

My question is, can I replace the bearing without removing the back half of the driveshaft? if remove the front and seperate the two halves, will the bearing come off with the front half? or if not, can I do the replacement under the car? I've heard that sometimes you have to have the bearing pressed onto the shaft, and that would require pulling it and taking it into the shop...

Anybody done this???

Thanks..

 

[epj3]

Yes, there's NO reason to remove the driveshaft from the differential. The bearing comes off on the front half (which you can see just by looking at the expansion coupling)

There should be a guibo on it, all BMW's since a very long time ago had one, so maybe you should invest in one to put on there... I think a mechanic might've gotten cheap and just put the flanges together (which is a big no-no). Remember to mark the driveshaft on both halves with a white marker or chalk, so you can put it back together correctly (if you don't it will be unbalanced and cuase a very harsh vibration all the time).

It should look like this when you pull it out
http://www.bmwchannel.com/eric/clutch/100_5809.jpg (thats the front half)

http://www.bmwchannel.com/eric/clutch/100_5805.jpg is what the front half (guibo) should look like.

You shouldn't be removing ANY bolts that is near ANY of the U joints....
http://www.realoem.com/bmw/showpart...=47321&prod=19870100&btnr=26_0004&hg=26&fg=05

 

[DigDug]

Yes, there's NO reason to remove the driveshaft from the differential. The bearing comes off on the front half (which you can see just by looking at the expansion coupling)

Excellent!!! Just from looking at it I thought it would work without removing the back half...

There should be a guibo on it, all BMW's since a very long time ago had one, so maybe you should invest in one to put on there... I think a mechanic might've gotten cheap and just put the flanges together (which is a big no-no). Remember to mark the driveshaft on both halves with a white marker or chalk, so you can put it back together correctly (if you don't it will be unbalanced and cuase a very harsh vibration all the time).

It should look like this when you pull it out
http://www.bmwchannel.com/eric/clutch/100_5809.jpg (thats the front half)

http://www.bmwchannel.com/eric/clutch/100_5805.jpg is what the front half (guibo) should look like.

You shouldn't be removing ANY bolts that is near ANY of the U joints....
http://www.realoem.com/bmw/showpart...=47321&prod=19870100&btnr=26_0004&hg=26&fg=05

Yeah, I was surprised not to see the guibo once I got it off of there. The pictures are very helpful... thanks...

I really dont' see how the guibo would fit... The driveshaft that's in there now has a u-joint at the front and bolts directly onto a plate on the transmission output shaft. I'm working out of the Haynes manual (I know I'm going to get crap for that), and it has pictures of both the u-joint type and the guibo type. (although the pitcure it has with the u-joint type is off of a 5-series). I'm wondering what type of work has been done... Maybe the previous owner swapped a 5-series transmission in there along with the driveshaft... or maybe BMW didn't 'guibo' this model for some reason? Strange to me... Maybe because it's the automatic???

I don't see how I could put a guibo in without replacing the driveshaft and the transmission output flange...

I've attached a picture of what my setup looks like (hopefully I attached it correctly). This is the forward end of the driveshaft.

Anyone have any ideas???

 

[epj3]

AH I knew something was fishy.. you have an automatic transmission which doesnt have a guibo since the transmission setup itself actually can dampen a lot of road feel (torque converter.)

Buy some PB Blaster at autozone or wherever. It'll do WONDERS, its smelly but its like hard core wd40.

 

[DigDug]

AH I knew something was fishy.. you have an automatic transmission which doesnt have a guibo since the transmission setup itself actually can dampen a lot of road feel (torque converter.)

Buy some PB Blaster at autozone or wherever. It'll do WONDERS, its smelly but its like hard core wd40.

Ahh.. I thought I was going crazy for a minute... I got the front u-joint bolts lose (soaking them in WD-40 for a few days) and using good old elbow grease... I'll get at it again tomorrow, but it sounds like if I losen the collar, drop the center support bearing, lower the center section, I should be able to pull the front u-joint off the transmission... Then I just slide the splines apart and remove the front section for access to the bearing....

I wish I would have thought about that before I spent all that time trying to get the rear u-joint bolts lose... Good thing that joint is in good shape...

Thanks alot for the advice!!!!

 

[epj3]

Ahh.. I thought I was going crazy for a minute... I got the front u-joint bolts lose (soaking them in WD-40 for a few days) and using good old elbow grease... I'll get at it again tomorrow, but it sounds like if I losen the collar, drop the center support bearing, lower the center section, I should be able to pull the front u-joint off the transmission... Then I just slide the splines apart and remove the front section for access to the bearing....

I wish I would have thought about that before I spent all that time trying to get the rear u-joint bolts lose... Good thing that joint is in good shape...

Thanks alot for the advice!!!!

Just remember to mark where the driveshaft so the 2 halves go back together the same!

 

[DigDug]

I got it out!!! More problems?

Thanks to epj3, I was able to get the front section out... [headbang] (not too bad afterall thanks to the inside scoop), but I think I may have found another bigger (read more expensive) problem. I think the driveshaft may have to be replaced.

The center support bearing seems to spin nicely and doesn't have any play (This job was to eliminate a low speed, 2-15 MPH, vibration that has been getting worse and worse), so I think it's good.

The problem is the U-joints. There's no play in them, but they are STIFF!!!! the rear section (still in the car) moves around smoothly in all directions, but the 2 joints on the front half are STIFF. I have to CRANK on the hard to get them to move. On other cars I've worked on, the u-joints are floppy (ie, if you hold the shaft, the mounting plate falls on its own...), but these are not.

My question is... do you guys think these are bad and the driveshaft needs to be replaced? If so, I've read that these joints are not serviceable (I'm assuming by the home mechanic) and the whole shaft needs to be replaced (PB blaster here I come for the rear half). Has anyone had any luck bringing the shaft into a driveline shop and having them re-build it? That would save me from having to fork over the cash for a whole new shaft, as well as breaking more knuckles trying to get the back half off...

I've attached a picture of the removed shaft half, highlighting the stiff joints...

Any thoughts???