1936 vibration

[1936 Viper]

Have drive train vibration 30 - 40 mph. Have replaced rubber mounts, rear axel bearings, new type driveshaft and universals. Next stop transmission. Any suggestions?

LP  1936 Dodge D2 TS 29 K miles

[1936 Viper]

Smooths out at 50 mph but it’s like breaking the sound barrier

LP 

[JACK M]

Does it go away if you lift off the throttle and push in the clutch?

Can you make the vibration vary with the throttle?

Is it more profound with harder acceleration or deceleration?

Does it seem to follow engine speed? Does it do it in second gear the same as hi gear?

Or does it follow road speed? So maybe a tire?

Need to pinpoint the source, have someone climb around the car listening for where it may be coming from. (front? rear? right? left? etc.

A tire or wheel (even a wheel bearing) vibration has a different tone than a drive line vibration.

 

I had a drive line problem a few years ago, (actually chased it for a few years) I had it balanced by more than one place and was deemed good, but still had the vibration. I tried changing the pinion and engine angles, even tried a different transmission and a different third member.

I was sure it had to be the driveline. In frustration I had a new driveline built with all new everything and the vibration went away even though it had had the balance checked by experts several times.

My theory is that the experts only balance the drive line when it is perfectly straight, not putting the U-joints at any angle like in real use. Never did determine the exact cause. But you can be sure that this particular driveline doesn't exist anymore.

 

 

 

 

 

 

Edited 13 hours ago by JACK M (see edit history)

[nat]

2 hours ago, 1936 Viper said:

Have replaced universals.

     Are the universal joints aligned?  The bearing caps in the center section of drive shaft should be in perfect alignment.  One spline off is enough to cause vibration.   U joints are totally inefective when the bearings are 90 degrees to each other. 

[1936 Viper]

Will check 

[1936 Viper]

Jackm

seems to be speed oriented new tires changed wheels balanced steering stabilizer new driveshaft and universals will check universal alignment like nat suggested. Did front bearings did rear bearings rear end good took out driveshaft again rebalanced tried flipping it around had previously replaced transmission mount. Will look at transmission next 

LP