Got new gears installed along with coast double cardin front ds and am gettn vibration now. So from what I read is that I may hav to adjust castor to remedy? I also hav read that they suggest o pinion angle or say that a double cardin ds prefers o pinion angle? Is it all trial an error or has any one come up with any degree of castor that works good with them? Any an all help is appreciative.

 

Search the forum for the many threads about t-case explosions. Lots of info for "the recipe for disaster".

Double cardans require the single joint on the other end to be within just a few degrees of straight.

Until you get the vibrations fixed, assuming it's the front drive shaft, don't drive anywhere near highway speed.

 

yeah, if you've got vibes, you've most likely got too much positive caster set on your front axle. i would try to set it to as close to stock as possible which would be +4°

 

You need to get a $8 angle finder at a minimum to obtain your caster angle and pinion angle... You don't need to run zero pinion angle, but you will have to find a Happy place between good caster and no vibrations.

I run 4.2* caster on 35's with a 4" long arm lift - Coast 1310 shaft and I'm vibration free with outstanding road manners.

 

Had dealer check an it was 3.5 positive an decided to readjust uppers to try to get closer to 4.2 and may hav over adjusted cause I think I even felt a little vibe after I did. Will adjust bak to where it was an c what happens.

 

Do you have an angle finder?

http://www.sears.com/shc/s/p_10153_1...1548000P?mv=rr

http://www.homedepot.com/buy/tools-h...or-114945.html

Above are two links to some $12 Johnson Magnetic Angle finders. Don't pay the alignment shop to tell you your caster numbers. Without knowing your angle when you make adjustments you'll never get it where it needs to be or take way too much time and frustration

Or if you want something to give you angle in 10th of a degree this is what I utilize. http://www.longacreracing.com/catalo...d=1209&catid=5

Good luck!

BR-

 

You also need to check the u-joints on your drive shaft. When I installed my front drive shaft I had a bad vibe over 45 MPH. I took it to an alignment shop to adjust my pinion angle, and it did not help. When I got home I realized the u-joint was not properly sitting within the groves before I tightened down the u-bolts.

You should have two little nipples on the yokes that properly seat the u-joint. Just make sure the edge of the u-joint is not tightened down on top of them.

 

Will defintly check that out! Thanks for pik.

 

No problem, that's what this forum is for.