Holy Moly: Replacing the Driveshaft Center Support bearing

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Slownrusty
Posts: 617
Joined: Wed Apr 24, 2019 2:22 pm
Location: Houston, TX

Holy Moly: Replacing the Driveshaft Center Support bearing

Post by Slownrusty »

My first post! Hello everybody.

So..while replacing or upgrading my shifter to a short shifter, I had a "while I'm in there moment" so decided to replace the center support bearing.

Working on my driveway with the car on jack stands a few inches from forehead.

1) Remove the 4x17mm (M10) nuts holding the companion flange of the drive shaft to the rear diff...do your best not to round them off as they are self-lockers. Requires an open ended wrench with a cheater bar, and in the process of removing them..a few of the nuts actually take a beating and now you have to re-order a new set from BMW (fortunately available for $1.20 each).

2) While removing the above nuts don't let the wrench and the cheater bar fall on your forehead and make a bloody mess....too late. Take two (2) minutes to mop up the blood and catch your breath.

3) Driveshaft is out.

4) Mark the driveshaft clearly on both sides with a paint pen or grease pen as they are balanced together.

5) Try to figure out how to separate the driveshaft halves, then realize there is some kind of threaded collar that is the "mechanical joint". That collar is so large even my largest 34mm open wrench doesn't fit, get a pipe wrench and cheater bar and still no budge. Ask my wife to come out and help, let her hold a pry bar with a cheater bar placed in the U-Joint to counter me as I try to loosen that collar with the pipe wrench. No luck..take another 2 minutes to mop up my bloody forehead, calm my wife down that I'm not going to die from major blood loss...realize its now 9pm and working in the dark on my driveway on a broken down Amazon cardboard box is no fun.

6) Time to bring out the big guns...fire! Light up the Map Gas torch place it on that
threaded collar for a few minutes until "stuff" starts oozing out of it...get it really nice and hot. Time to try the pipe wrench again with the cheater bar with the wife continuing to help..voila the collar starts moving slowly...victory. Wife goes into the house and says "good luck!" The collar is now beat to crap and fortunately you can get a new one for $12.

7) Surprisingly, I still can't separate the driveshaft halves scratch my head..I don't have a big enough vice to place it in and "work it loose"....decide to use my 7lb sledge and hammer against the old center support bearing working in 360 degrees around the circumference, notice the splines are rusty and probably the reason why its stubborn. Slowly I see they are separating with the blows from the sledge...a few minutes later they are apart....

8) Sit on my flattened Amazon cardboard box "chair" on the driveway in amazement of the last 2-hours.
GRNSHRK
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Re: Holy Moly: Replacing the Driveshaft Center Support bearing

Post by GRNSHRK »

Great first post Slownrusty =D>

Sorry, but I had to laugh about the spanner in the forehead part of your story #-o

IIRC, the 2 halves of the driveshaft should slide apart, so it sounds like the rusted splines were the culprit :-k

Welcome to the madness 8)

Looking forward to more of your stories, you've got a knack for writing :lol:
:mrgreen:
Bobbo
1980 633 CSi Cypress Green/Pearl Beige
2017 X5 M Sport Xdrive 35i Carbon Black/Ivory White
2005 330 Ci ZHP Cabrio Imola Red/Bone/Black
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brickwhite
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Joined: Wed Sep 01, 2010 3:29 pm
Location: Broomfield, CO

Re: Holy Moly: Replacing the Driveshaft Center Support bearing

Post by brickwhite »

Some use the e34 center bearing as an upgrade instead of the e28/e24 one. It's a little beefier.

PN - 26121226723

https://www.fcpeuro.com/products/bmw-dr ... 6121226723

when I installed mine...don't forget to preload!

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Last edited by brickwhite on Wed Apr 24, 2019 7:37 pm, edited 2 times in total.
- 12 535i
- 92 325ic
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Slownrusty
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Location: Houston, TX

Re: Holy Moly: Replacing the Driveshaft Center Support bearing

Post by Slownrusty »

@GRNSHRK -Thank you kind sir for the warm welcome! I appreciate your feedback and glad we could share some laughs on my night's escapades.

@brickwhite - Awesome! I appreciate the suggestion, I already bought a new E24 based CSB, but can return it and I can order the better designed E34 bearing.

Glad to aboard the SS Madenss and be part of the nautical journey, be aware of the big fish, here is mine.


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JCS
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Re: Holy Moly: Replacing the Driveshaft Center Support bearing

Post by JCS »

Welcome Rusty,

Your car is identical to my first bimmer a new '86 635 in Bronsit.

Best,
Jay
'88 M6, Red/Tan
My NEW Website https://www.jaysbmwparts.com/
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Slownrusty
Posts: 617
Joined: Wed Apr 24, 2019 2:22 pm
Location: Houston, TX

Re: Holy Moly: Replacing the Driveshaft Center Support bearing

Post by Slownrusty »

brickwhite wrote: Wed Apr 24, 2019 5:47 pm when I installed mine...don't forget to preload!

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Yikes..."preload"....glad you mentioned that (thanks!)...I did a search and did not find any threads. Can you please provide some pointers on preloading this bearing before I end up wrecking it and ending up with another bloody gash in my forehead.

Thanks brickwhite!

Yasin
brickwhite
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Location: Broomfield, CO

Re: Holy Moly: Replacing the Driveshaft Center Support bearing

Post by brickwhite »

Simple google search for e28 or e24 center support bearing. Green bently e28 manual is helpfull too.

http://www.mye28.com/viewtopic.php?t=45129

https://www.amazon.com/gp/offer-listing ... ition=used

here's some decent writetups..

https://www.pelicanparts.com/BMW/techar ... earing.htm

https://www.bimmerforums.com/forum/show ... eplacement

Also check out your centering bushing at the end of the driveshaft...those are a pain to get out... I use the old bread trick.. works everytime...

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- 12 535i
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EdwasRed
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Location: St Louis, MO

Re: Holy Moly: Replacing the Driveshaft Center Support bearing

Post by EdwasRed »

Have you checked the rubber flex-plate (guibo) to make sure it isn't too worn? It's a pain but seeing as you are this far in it might be worth checking.

Also, be sure to apply some moly coat to the splines on your drive shaft. Hopefully you won't ever have to drop your drive shaft again but you never know.

Looking forward to reading more about your project.
1985 635CSi M Euro M88
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Slownrusty
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Location: Houston, TX

Re: Holy Moly: Replacing the Driveshaft Center Support bearing

Post by Slownrusty »

EdwasRed - Yes I am replacing the Flexdisk while I'm at it. And I definitely plan to make the splines on the drive shaft squeaky clean prior to re-installation
brickwhite - Thanks for the links and I bought a new E34 CSB as well.

I appreciate all the help fellas!
Yasin
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