coobah

Hi

Want to replace my driveshaft support/bearing. Will it be doable by removing only the rear part of the driveshaft? (by sliding the splines out)

anomadtoo

if you haven't I'd suggest replace both your flex discs while under there too since it'll be easier; and thus you might as well remove the whole thing for easier access to both; and get it all done at once.

coobah

Well, thanks for your suggestion but if I'd like to do it all... most probably I wouldn't ask.

But.... we should all know it by tomorrow

anomadtoo

Yes true haha
but seriously check your flex discs while there; I replaced both mine the other week at 84k miles

coobah

Will surely check them out. I did replace them unnecessarily once (in one of my previous cars)

The thing is that I'm dealing with highway vibration and I'm not sure if I wont have to replace whole driveshaft assembly anyway and...:
- I'm almost sure that my support is shot as I see it "flexed" to the bottom (the bearing does not sit in the center ATM)
- I have to disassemble my exhaust in the middle anyway to fix broken bolts.
- Having the rear driveshaft half out would let me examine the u-joint

EDIT:
BTW: Is it possible to replace the u-joint in E55 driveshaft?

coobah

So.... I'm back with a bit more knowledge

It is possible (and actually pretty easy) to get to driveshaft support without removing the whole exhaust/driveshaft. The middle exhaust heatshield (covering support bearing) is made of 2 pieces, so you can remove it with the driveshaft still on.
You lower the exhaust. Remove the heat shield. Unbolt the support bearing, so you have plenty of room to disconnect the rear flex disk as a next step and the rear half is all yours.

I have no resonator (two tubes instead of it) so I did remove them with ease but I think that anyone with stock exhaust should be able to separate it in the middle and do all of the driveshaft related work with the aft half of exhaust lowered (not removed completely). Again I'm not telling its's the best way but in some cases can be.

The splines in the middle of the shaft are slid half way in when everything is assemled on the car. The support bearing holds the rear part of the driveshaft, so:
- to replace the front flex disk you wont have to do anything (the front of the shaft can slide a few good cms on the splines)
- to replace the rear flex disk I'd recommend unbolting the support in the middle (so again it can slide on the splines and not stress the support rubber too much during the fight)

Going back to my situation...Yes anomadtoo You were absolutely right. Both of my flex disks start to show some age when abused with a crowbar
Beside of flex discs.
- My spline cover/rubber is gone (found most of it on the heat shield)
- My u-joints feel "notchy" I mean both ujoints have no play at all, but they feel a bit more loose in the center and a bit tighter when rotated to the sides, giving "notchy" feel when trying to move the whole spline/yoke in circular motion.
- My support rubber was pretty ok, but I did install the new one (which is a bit more "centered")

I think I can feel the vibration even a bit more now (maybe because of a bit more "rigid" rubber in the middle)

Does anybody have some experience with driveshaft vibration (or driveshafts in general) in our cars?
Is a bit "loose in the middle ujoint feeling" quite normal, or is it surely causing vibration? (I had a lot worse ujoints in my Jeep many times and felt nothing but that's probably a different story)
Maybe it's normal and my driveshaft is most probably unbalanced?
Can it be my flex discs causing vibration?

I personally (and a couple of my friends) have no good/satisfying experience with "driveshat overhaul" companies.
My car has 120k kms so I don't think I'll fnd a lot of 2nd hand driveshafts which are better than my one (eg. the rubber on the support is torn on most of them).

I really don't know what to do next....and I'm really starting to think about replacing the u joints. You could grind the "press points" with a Dremel and hold the new u-joint with a small TIG tacks.... hmmmm....

Andres Morejon

Hey I am currently replacing my flex disc and bearing/carrier over vibration issues on either side. There seems to be a little metal cone piece on either side of the bearing and wondered if they are needed or no. I did the work once and the vibration is worse. I cant find that collar online anywhere so wondering if you guys have one on yours or not. I'm thinking the bearing is meant to sit at the very back of the splined piece and get rid of the collars i banged up on accident. Going to take it down Wednesday and could use the help or any advice from others who have already done this. thanks