[davepl]

I had a REALLY strange one (bad shudder under light accel from a stop). After trying just about everything and giving up, I took the driveshafts to a local specialty shop. They found wear in the splined section.

I couldn't feel it, and honestly thought I was being scammed, but I was desperate and so I relented and let them replace the whole splined section. They did that and it solved the problem.

Lesson learned: there's a lot about driveshafts that I don't know, and I was surprised at the weird problems they can solve/cause.

If you have a friend or some other access to a 2-piece driveshaft, it'd be a cheap test if you could swap to see if the problem transfers over or goes away.