Molitoth

Hi Team!

I'm desperately looking for an answer about my Cardan Shaft disaster and hoping someone here can help me before I decide to go pay a lot of money for someone else to do it. =(

Last week I noticed the heavy vibrations under my armrest during acceleration in my CTT. I knew right away based off reading this forum that most likely it was the cardan shaft.

Being the DYI type of person I am, I decided to order the new Support Bearing and do the job myself on the cheap.
Following the instructions from other members posts and the DYI guide from Renntech, I easily got the shaft out of the car, pulled it apart, and replaced the support bearing. I put it all back together and back in the car and took it for a drive. Now the vibration is massively worse. It all feels fine until the car gets to about 20+ mph and then the whole car just feels like it is going to wobble loose.

I've taken the shaft back out numerous times, checking over and over again if I have done something wrong. I've double checked if I put the bearing support on the right way (check). I've checked to see if my flex disc is mounted properly (check). I've re-aligned the shaft to the marks that were made before I took it all apart (check).

The only thing I can think of is that I somehow screwed up putting the bearing cage back together. I just don't see how I could've done that though because I think it only clips in 1 way.

I'm about to order a rebuilt shaft and install it myself to see if a new one fixes me issue. If not, I will have to take it to a stealership and pay out my ***. (money I wanted to spend on new wheels and tires).

Could this whole massive vibration thing be ANYTHING other than my rear drive shaft?

thanks for any help!

endless_corners

Make sure to replace the flex disk if going rebuilt. Vertex's rebuilt shaft ship with one. Also, could one of your wheels have gotten bent somehow?

XR4Tim

Make sure the bearing is aligned correctly. If it is mounted up to the left or to the right of center, the front and rear portions of the drive shaft will not form a straight line, and it will produce heavy vibrations.

Molitoth

I've read conflicting reports about the flex disc. Some people say be SURE to replace it, and others say it's typically fine a good percentage of the time.
I've visually inspected mine and it looks like it's in fine shape. No cracks, etc.
but maybe the rubber is too flexible? I can bend it pretty easily with my hand.

I don't have the alignment tool, although I did follow the advice from the Renntech DYI guide... finding it's natural resting place and such.
The rubber boot containing the new support bearing is somewhat flexible enough to where I can physically move that section of the shaft with some force even when tightened if I wanted to.

endless_corners

One of the main guys at vertex said when they first started selling new and rebuilt driveshafts they didnt include the flex disk. But as time went on they started discovering it to be a source of secondary vibration from customers installing new/rebuilt shafts. He said that doing a physical inspection wont really help since all it takes a small amount of difference in the behavior of the rubber in one area to cause asymmetry. I dont think the flex disc ALWAYS needs to be replaced when doing the job. It is a really thick heavy duty piece of rubber. But it CAN be a source of vibration and replacing it is easy and rules out a variable when trouble shooting. YMMV