Drivetrain Rumble/vibration?

[wolk625]

Since I've gotten the '41 fully streetable, I've noticed that while rolling at a pretty good pace and under throttle/load, there's a pretty intense/loud vibration sometimes, but when I let off throttle and coast it goes away. Is this most likely bad u-joints on the driveshaft, or should I be looking elsewhere?

[DJ194950]

Motor mounts in good shape??

 

DJ

[greg g]

Try reindexing your drive shaft. Remove it from one of the flanges, revolve it or the flange 180 degrees and see if it makes any difference.

[Dodgeb4ya]

Check the drive shaft to housing ends for looseness in/out of the car. Possibly worn ball and Trunnion's. Common issue.

[dpollo]

All of the above.   you can also take the cover off the rear joint and insert a washer under the center pin which holds the spring.

Put the cover back on and reassemble.  This has the effect of causing the rollers to operate in a less worn area.

 

The real fix is , of course to rebuild the joints which is a bit of a challenge and can be expensive.