Dear Metallo,

Hope you're well and stay so. Glad to hear that the vibration source has been found.

I recall a long-ago post, from which I learned that the bolts - that secure the driveshaft to the transmission output flange and to the rear-end flange - are used to balance the driveshaft. So, when removing the bolts, number each one to its position. If this is done before disassembly, the bolts can be replaced in exactly the same places that they were, when the car left the factory.

Rather than relying on applied markings (e.g., paint, that can rub-off), I'd use a pointed punch to mark each hole in the flanges and each of the bolt heads, e.g., one "dimple", two "dimples" etc. Put into a plastic bag each set of four bolts. Label each bag according to the flange to which the bolts belong, e.g., "front", "rear".

I don't recall that the nuts need to be so marked, but it might be best to do so. That will ensure that after the U-joints and center bearing are replaced, the driveshaft will be as it was, when it left the factory.

Hope this helps.

Yours faithfully,

Spook