driveline question

[gmcman]

I have I think a 6" lift on an 81 gmc 1/2 ton full size.In the front I have 2 or 2 1/2 degree shims. My trouble is driveline vibration I believe due to mismatched angles. On the t-case end I have a cv-joint and on the pinion a u-joint at approx 7-8 degrees. My research has told me with a cv joint driveline the u joint end must be only about 1 degree. How much can I shim the axle to change this angle? And how will this affect my steering control. This is my DD and does see some highway use.Any help would be appreciated!!

 

[cybrfire]

I don't think you'll have much luck shimming far enough to make your drive line angles perfect. You may be able to get away with 4* and eliminate enough of the vibes to have a happy medium.

If I'm reading your post right, you need an additional 7-8* to be dead on. This much will totally eliminate your caster angle. That will bring the suck.

 

[apache]

If you getting vibes from the front DS you must be running in 4wd at speeds?? Personally Ive never had to shim a front end but have also never lifted over 6". Id for one read up on Tom Woods website ,geometry 101 for some info and facts. It seems no two vehicles are ever the same exactly but the basics exist. Might be time to mod the front axle to get it right.

 

[4X4HIGH]

It is true about the pinion pointing at the driveline when running a CV jointed shaft but this is for a rear shaft and not a front. You should never be running the thing at speed in 4WD on the street/freeway.

 

[apache]

I was under the impression from the wording he was talking front D/S?? got thinking maybe he has a 203 and full time still also?? dunno