How important is it to have this done? My Muncie is freshly rebuilt with 500 miles on it and I replaced the u-joints on the driveshaft. Also installed a new yoke for the tranny. Most recently I replaced the old Muncie shifter and linkage with a Hurst super/comp. The Muncie really used to rattle/vibrate to the point where I always rested my hand on the handle to keep it quiet.
Now I still notice a vibration with the Hurst but it's different in that it seems to vibrate the whole car and increases as RPM's climb. So I solved the handle vibration but it seems to have moved to the whole car! graemlins/angry.gif Would it be a good idea to start with getting the driveshaft balanced or any other suggestions? At least it shifts a lot nicer!!

Scott,
There is a VERY good chance that your driveshaft needs to be balanced. It is POSSIBLE that it may also be twisted ever so slightly (which will induce a slight vibration). Or, if it has ever been dropped or been subjected to serious driveline abuse, it could be slightly out of whack. I'd have it checked. If nothing else, it will at least eliminate one possible source of vibration. And of course, ALWAYS check the balance on your tires.

Tom,
Where would I find someone that does this type of work? Guess I should just call a local speed shop and get leads from there. I'm thinking it's not the tires because I would have noticed the car's vibration before I made the shifter swap but may just rebalance them if the driveshaft balancing doesn't solve it. graemlins/thumbsup.gif

Drivetrain vibration can also be induced if you didn't install the u-joints properly. They should be able to flop about freely and should not provide any noticeable resistance when moving the joints by hand. Often times after new joints are installed the yokes are slightly narrowed down by pounding or pressing the cups in place which induces friction into the joint movement. This can be relieved by striking the corners of the yokes below the joint cups to relieve this built up stress. Sounds odd but it works and I was instructed how to do it by a driveline shop manager. This should be done with the driveshaft off the car of course.

Especially with a new yoke being part of the package, a balancing/straightening job is likely in order. The longer you wait to get this addressed, the more stress this will put on your pinion and tailshaft seals and bearings/bushings.

Are you positive it's in the driveline. I had a vibration also driving down the road and when I went faster it got worse. But then I noticed when I pushed in the clutch and coasted it went away. Pressure plate was out of balance.

Rich,
Thanks for the reply. I need to get that thing checked out and balanced as I certainly don't need any "added wear" since it was newly rebuilt.

66 ss,
Am I correct in assuming that once a pressure plate is out of balance, you can't fix/rebalance it but would need to replace it? What makes them wear crooked or get out of balance?

If you install a new tranny yoke, the driveline needs to be rebalanced as the yoke and driveline are balanced as an assembly. (Mark the driveline to yoke relationship so you can replace it the same way in the future should you take it apart.)

Also, your yoke may have runout issues. Again, the balancing shop will easily see this and let you know.

Troy

Put a new one on problem went away.

Double check the bolts or nuts on the U joints being held in. Make sure they are tightened evenly. I fixed vibration problems several times this way.

Also could be tires out of balance or unusual wear if worn from a bad front end/alignment problem.

I had my drive shaft balanced when I had it cut to size after replacing drive train pieces. Check the yellow pages or online resources such as switchboard.com to see if there are any places in the area.

Steve