Driveline vibration

CalMI

CalMI

Member
Just got my 36 3W on the road. Runs and drives great. However it seems that there is a vibration at higher speeds. In direct it vibrates as speeds get above 45 MPH. I then shift Columbia into OD and the vibration goes away until I speed up to around 60-65. I believe the driveshaft is the tubular shaft not solid. Any thoughts?
 
Could be a tire out of balance. (you can usually feel it as a fast thump) Your drive shaft might be out of balance. You might have a bad ujoint; The pinion angle could be off.
My 53 Merc had a high speed vibration, that I never figured out. It still had it 6 years later when I sold it. I checked all these things. Good luck Hugh
 
Sounds driveshaft related. The harmonics of vibration will appear at the "ideal" RPMs. When you shift into OD you slow the driveshaft revolutions to cause the vibration to appear at a higher MPH.

Driveshaft should be checked for trueness, balance, and phasing of the universal joints. Pinion angle should be cancelling the tailshaft angle. Check your tailshaft bushing and yoke for wear.
 
Grease the u joint with a mixture of chassis grease and gear oil.Your problem sure sounds like a dry u joint to me.
Don
 
I have the same problem on my 50 Merc and I think it is drive shaft related too. I just bought the car and it starts to vibrate at 30MPH and when I am crusing around 60MPH some times it go's away for a bit. I have not greased it but the car is going up on the hoist later this week I will get them to inspect the u-joints at the same time.
 
Definately sounds like drive shaft related. (U Joint, front drive shaft bearing, rear coupling or the drive shaft itself. I do not think Pinion Angle and phasing of the U joints has anything to do with it if you still have the original Torque tube.

As recomended before, I would lube the U Joint and if that does not take care of it, the rear end may have to come out of the car. If so, check the front drive shaft bearing and outer race and also the end of the drive shaft where the bearing rides. Often this stuff is worn out. Also check the U Joint for wear and the rear coupling where it fits onto the end of the pinion. Also check to be sure the drive shaft is straight. If everything looks good, you may want to take the drive shaft to a drive shaft shop and have them check the balance.

Let us know how you make out,

Chris
 
Hey guys, Thanks for all the input. I do have the original torque tube so there is no phasing of u-joints. I have been working on this car for 15 years and put the chassis together about 13 years ago so I don't remember if things were greased or not. I have several things to check. I did not balance the tires so I need to check that too.
Thanks for your help.
 
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