driveshaft vibration

[1989blazer]

My driveshaft is still vibrating a bit, contrary to my post a few months ago. Dang. I checked the angles between the driveshaft, transfer and axle and they're 9 and 12 degrees respectively. My question: at these angles do I need to go to a double carden shaft? I'm wondering if the axle is over-corrected and needs a 1 degree shim. I've been reading drivesaft sites and they seem to think a 1.5 to 2 degree correction is what's needed. I've got Rough Country springs in the rear, needless to say - stiff as hell. Anyone else solved a similar problem. Anyone got a 2" - 4" lift with standard drive shaft and no vibration? Anyone solved the problem by replacing old, worn shock absorbers?

 

[blazerpunk]

1980 K5 4" lift stock rear drive shaft. No vibration. /forums/images/graemlins/dunno.gif

 

[ugly_blazer]

Is your transfer case crossmember lowered?

 

[1989blazer]

cross member is lowered. I'm wondering if having different weight u-joints would make a difference.

 

[drivelineman]

you can take two of the same rigs side by side one will shake and the other will not- but you need a c/v and proper pinion angle 2 degree's working (actual angle) and it will be happy again-Jess

 

[1989blazer]

Yep, that's what I'm thinking. 9 degrees means a significantly lower u-joint life as well.