Driveline vibration

[poser]

I just put a 4inch lift on my 84 CJ7 the lift came with Transfer Case lowering mounts but I don't want to use them because of ground clearance so I bought a Tom woods cv driveshaft and still a vibration so what degree of axle shims should I go with any help would be great.

 

[Bucks86Renegade]

Hey Poser, check out this thread from recent. It was helpful to me.

http://www.jeep-cj.com/forums/f19/axle-shims-how-much-too-much-11769/

 

[gert]

you are going to have to go back to Tom's website and look at their guideline on measuring angles so you can figure it out as we will not be able to tell you...sorry

 

[BusaDave9]

I bought a Tom woods cv driveshaft and still a vibration so what degree of axle shims should I go with any help would be great.

If you have a CV joint (Double-Cardan joint) you should have zero degrees at the rear u-joint.

If all that is right and you still have vibration then maybe the vibration isn't from the drive shaft. Driveshaft vibration is a rotational vibration. It's like the driveshaft speeds up and slows down with each rotation.

 

[Kane]

TOm advised me to set up my rear end to have 0-3 degress for an angle on the rear u joint. Any more and you get vibration. I set mine for 3 degrees so when I am under power and the springs flex a bit the pumkin will rotate up and still keep a zero degree angle.

 

[BajaEdition]

you need to clock that rear diff, that may mean cutting and rewelding the pads. but the and needs to be a Kane specified, I do give it 2 extra degrees for tourque however, but I do that, it is not what the factory says

 

[BusaDave9]

TOm advised me to set up my rear end to have 0-3 degress for an angle on the rear u joint. Any more and you get vibration. I set mine for 3 degrees so when I am under power and the springs flex a bit the pumkin will rotate up and still keep a zero degree angle.

If you have a double-cardan joint almost everyone says the u-joint at the axle should have as close to zero degrees as possible. But in the book "Differentials: Identification, Restoration and Repair", Randy Lyman says you want to avoid 0 degrees. He says the u-joint will give odd wear pattern if it is set to 0 degrees. You are better off shooting for a couple of degrees.
That's an excellent book I recommend to anyone that is interested in 4x4s and axles. It's from the same Randy as the owner of Randy's Ring and Pinion