x91j

Hey guys just put my front drive shaft in and I went to drive the jeep and Woooow! All I can say is hello vibrations. I have a 4.5in lift with adjustable lower arms and stock uppers. Here's a pic of the angle. Will upper arms fix this?

ct67_72

Cant really tell from that pic. try to get something better, more level.

x91j

I snapped it real fast. We are in the middle of a blizzard lol.

PingPong

Your problem is your caster angle is off..

freegdr

looks high to me, vibe b4 shaft install

x91j

So how do i correct that? Adjustable upper arms?

freegdr

adjust lowers

caged

don't forget, you are now running your u-joints in a different pattern unlike what they were used to.

Trev1006

I believe the guy at Tom woods told me that on level ground that your pinion on you axle should match the angle of the pinion on the t case. Like if it points 7 degree down the axle pinion needs to point 7 degree up. So they are parallel. I did mine like this and no vibe. Also I think my caster I set at -4 degree( top one 4 degree behind bottom one) no vibes at all.

Trev1006

And I do believe it is a max of 9 degree per joint or it will vibe.

caged

short answer, you want your pinion pointing towards your output. the double cardan joint will take care of the angle at the t-case. (more for the rear tho).

for the front, if it's off too bad, you want to turn the knuckles.

x91j

I need to adjust the lowers in or out? I think they are set at 16.5" for the 4.5in of lift

Trev1006

But you only point the pinion at the output if you have the double carden. The single will vibe to death if you do.that.

x91j

I have a HP 30 with the double carden driveshaft.

Trev1006

Ok, then like caged said point that pinion right at the t case. How is your front caster? Have you checked it?