Drive shaft knocking noise after diff change - ideas?

[jameshoward]

I have recently changed the rear diff to get better gearing on my late 230. When testing the car, I now have a loud-ish clunk/knocking noise. I've run the car on a ramp and the noise is still there, but is more present at speed. There is nothing visible causing the knocking. The noise is similar to the noise you'd get if you banged on the shaft with a small hammer; quite tinny.

My next steps are to replace: the (for want of the correct term) the spider bearing/UJ where the shaft joins the diff; the center bearing, and the flex disc.

I'd be grateful if anyone has any other ideas of (a) what the cause might be (difficult, I appreciate, given my poor description), and (b) of anything else I could replace when I've got that lot apart.

Thanks in advance.

James

[w113dude]

James,
I can only think of one thing that might create that clunk sound, if the end shaft on your diff, was not tighten at the right torque, I'm sure others would have other suggestions.

[DaveB]

But weren't all those things that you plan to replace on the original driveline (without clunks)? Not that they couldn't go bad. Are you confident the new rear axle was good?
The loose bolt idea sounds good, and cheap. I guess you had to remove and replace many things during the swap. Any possibility the 'tinny' sound could be exhaust contact?