Shuddering at speed

[TimFX]

I'm getting a vibration, shuddering, while driving between 35mph and 50mph.  

Had the wheels and driveshaft balanced, still shaking. 

 

Ideas?

T

[knuckleharley]

Static or spin balancing?

Did you check the u-joints in the drive shaft for play?

[1949 Wraith]

What tires does your car have? I have some of the Coker Nostalgia radials 6.5 -16  and I get some vibration from flats spots that can be improved with increasing tire pressure. I run around 42 PSI and it is pretty bad vibration until the tires heat up and increase the pressure more.

[White Spyder]

I have the Cokers too. No issue and they are about 4 years old. Just need to drive it more often!

[greg g]

Try rotating the drive shaft 180 degrees.  Take it off the differential flange twist it 180 and fasten it back up.  Strange but might do the deed.  While you are under three, assure that the park brake is fully released when off.

Edited June 28, 2017 by greg g

[captden29]

my car was doing the same thing. no amount of tire balance helped. mine was a combo of spokes on old wire wheels getting loose and old tires. put the steel rims back on, new tires and the problem was solved. I never heard of rotating the driveshaft, but an easy thing to do and no money involved. I just wonder what it does?     capt den 

[knuckleharley]

4 hours ago, captden29 said:

my car was doing the same thing. no amount of tire balance helped. mine was a combo of spokes on old wire wheels getting loose and old tires. put the steel rims back on, new tires and the problem was solved. I never heard of rotating the driveshaft, but an easy thing to do and no money involved. I just wonder what it does?     capt den 

Sometimes a driveshaft is balanced and spins smoothly one way,but if you take it off and rotate it when you put it back in,it will be out of balance.

[rcb]

Have you had someone true the wheels? if they are spin balancing and the drop the shield they may not even notice. I've had bent rims before... just a touch off, but you could definitely tell it at speed. However, the wheel balanced just fine. Once you got fast enough it would smooth out.

[nonstop]

Check your pinion angle. My springs were sagging, which threw off my pinion angle. I added degree shims and my vibration is almost gone.