Hi,

I had replaced at the best shop in town all 3 u-joints and centerbearing. All were marked very carefully.

At first I had a pretty good vibration. I reset the new rubber donut and retorqued the center support. This helped a bit.

Surpisingly, when it got warmer, around 50 plus degrees the vibration was way less. It was around 12-20 again recently and the vibration returned to it's original 2nd effort self.

I suspect the donut position.

However, I have 1 flange bolt reversed due to a zirt fitting in the front u-joint. I also paid no attention to what bolt came out of what hole. I just tightened the bolts by hand as close as I could.

The 740 FAQ says the bolts should go back in their original hole, something about dynamic balancing. Is that true for my 89 240? I am going to pull the zirt and put the one bolt in like the others and try to torque.
What in the world do I do about the bolts if they are supposed to be in a particular hole??

I suppose you have to "custom" place the donut to try to get a level position from the front shaft to the back. I hear this is a very critical position. My donut spring seems to set to the side a bit.

Confused in Wichita