I have a 2000 xj 3.5 lift with a slip yoke kit and a 8.25 with a locker. The viberation is in the rear at 55-70 mph. I jacked up the rear and put it on stands to make sure and at about 55 on the speed o there it was. I thought it was the drive shaft so I put in a new one. Then I thought it was the tires so i rotated them. Anyone?

 

Is slip yoke kit and slip yoke eliminator? just to verify?

Full packs in the rear or AAL?

Did you put axle shims in between the axle and leaf springs

 

I hope when you replaced your drive shaft you replaced your U-jounts too. I would take the tired off and get them balanced especially if they are bigger than stock. Good Luck!!

 

Yea full packs in rear and yes slip yoke kit. The pinion angle is good and yea new u joints. It only has 31in tires so I dont think its them. I am going to look and see if its the trans mount today. But i think its more in the back than that.

 

What slip yoke kit do you have?

 

When did the vibration start? What mods or maintenance was done?

 

]With a single U-joint at each end of the driveshaft, the pinion angle MUST be parallel with the transfer case output, so each u-joint cancels the vibes from the other.



If you have a sye and a double cardan at the transfer case, you point the pinion directly at the transfer case so you have 0* difference between the pinion angle and driveshaft angle, meaning your pinion is pointed higher

 

Good pic but the castor shim is backwards

 

oh...so it is.