vibration from the back

[Tomi]

Hello,

I have had this slight vibration in the back which is not very big but is detectable and has become more and more annoying. It only comes at about 60 km/h speed at 70 it disappears and at 100 it gets even smoother.
I thought it was my old worn wheels that were out of balance, but now I have new wheels and no effect.

BTW last year I had an issue with the propeller shaft rear rubberdisk: one bolt was loose: I tightened it up and it did have some effect on the vibration.

Now I am almost certain this must come from the propeller shaft: either it is out of balance, the center supporting bearing is worn or the unversal bearing in the middle is worn. The rubberdisks look ok.
Anyway I am facing with having to take the shaft out, what a job, specially having to take the exhaust pipe out of the way.

Any other ideas

[Tomi]

hi styria, thanks for the reply. I went again under the car and the bolts seemed to be correctly installed with the washers on the rubber side. But a closer look at the rear flex disk revealed 2 cracks, so this must be the cause. Well having to take the whole shaft out it would be wise to change all the consumable parts: flex disks, center bearing, u- joint, perhaps the centering sleeves at the ends and then balancing the whole thing. This should be good for another 200000 km.

Today I made a 800 km trip from Lapland to south and it does make a slight vibration at the speed of 70 km/h and again at 140 km/h, which is the double of the first resonance vibration and is thus as according to theory

I will start this job within a few months as the weather gets warmer. Other than that, the car runs good. I just got it registered as an oldtimer, which means I dont pay any yearly tax and the insurance bill is very small. But this is not my daily car, and an oldtimer should not be one (according to the law here).

regards