SO i bought a car in my sig from a buddy, old roomate actually, and was told it had a vibration and it needed a Flex Plate. No big deal i thouhgt and i ordered it after noticing the vibration myself and buying the car.

No hard feelings i knew it was what his transmission guy told him and it sounded reasonable enough. Here is what I have done in order IIRC

1. drive it around and pretend it didn't bother me so bad
2. get it up on ramps and check out the flex plates. Both looked good, not one crack and words facing front, appear original but it fine shape.
3. drive around and slap it in neutral at speed to see if it was engine related, it wasn't. It doesn't change with load, rpms, turning, or braking just controlled by speed. (worst at about 26-40mph)
4. got it back up on jacks and greased the U-joint a little to see if it smoothed out any, Possibly some slight change but not really just hopeful I think.
5. Got it back up on ramps to look for the alignment marks. Found out that even though they are 180degrees apart, it may not matter as my car vin plate says 7/82 one month before they started using the two hashes and the tic on the flat spot.
6. went ahead and pulled the exhaust, and the driveshaft out of the car, well the back half and the carrier. I left the front half attached to the tranny.

so that is where i am at. The U-joint is free but it has a tick like it wants to stay right where it is, it clicks each way (up and down or left and right) but it is not locked, nor do any of the bearings or caps looked cracked or worn out.

The carrier bearing seemed to make some pops when turning it suspended while the shafts were attached but then coming out to the ground it just spins without terrible noise Albeit slowly. the bushing surrounding it does have a crack at the bottom and i was able to push pull it up and down maybe an inch while it was all still bolted up under the car. I thought it was supposed to be pretty stiff but the rubber seemed really compliant and i could lift and lower the entire driveshaft with one hand and see the movement.


There were disassembly marks from a scratching it looked like, I marked those also and they were way out from the Mercedes marks, but then again they may not have been balanced there.


Questions
1. Carrier bearing definitely bad with that much play in it? (Methinks SO)
2. U-Joint, how do you know when it is too bad to leave in there? total failure and explosion? I am willing to grind, press, and stake or weld myself here at home. (i have the technology)
3. Flex disks look great, i think i will just hold onto the brand new one i just bought as a spare and use lock-tight on the bolts when i reassemble, Sound OK to everybody?
4. Should i reuse the original, to me, marks? or should i re-clock the driveshaft to the V and Tick marks that may or may not be right? ( i am thinking carrier bearing and OG marks, then try the second ones if it is no better)