About a month ago I installed a Rugged Ridge S.Y.E The first 3 or days it was incredibly smoother. I was reluctant to install one seeing as how I only run a 3" lift, but I had bad vibes and went thru u-joints ever 8-10 months. Now I have extremely horribly terrible low speed vibes. It can only be felt at 15 mph and lower. The t-case is the only thing I can think of that would cause it. I readjusted the pinion angle, swapped shafts multiple times so check for balance and u-joint issues. Are there any common issues with installing an S.Y.E that I may have over looked causing my vibes? Anyone with experinece can tell me where to start because right now I'm looking at exploritory surgery which I'd rather not do unless I can pin point the problem either in the case or something else. Any help before my T-case implodes?

 

I was hoping to see other replies to this by now but I'll throw in my thoughts.

I would guess either a bent drive shaft, bad U joins, or the yoke isn't bolted on true. Those are the first things that come to mind (after making sure everything is torqued down nice and tight of course).

GL and keep us posted.

 

Agreed with Trumpster. Make sure to see if this is coincidence and the front DS isn't giving you hell. What is your pinion angle right now? With a double cardan DS it should be pointing either at or slightly below the tcase output depending on how much give there is when you accelerate

 

What drive shaft you using ? Can you post up pics ?

 

I'm at work so I don't have any pictures of it. I just put in 4* steel shims and my pinion angle is the best it has ever been, so I know thats good. Not to mention pre to post pinion angle...no vibe difference. Its defineately not the shaft(s) I use the same shaft front and rear (stock mid 90's XJ) Both are the exact same length... and I've tried each one individually in the rear both with and without the front installed. What would make the yoke not sit true tho? and wouldnt a balance issue like all of the above mentioned get worse with an increase in speed? Once I hit 15 MPH anything else above that to 75MPH is smoother than the day I bought it bone stock.

 

Did you install shims to point your rear pinion directly at the the t-case output?

 

did you install shims after sye install post up pics of angle possibly to high ?

 

I did the shims after the S.Y.E. I did it hoping that a low angle was the problem...Right now it is pointing directly at the T-case...if anything it is slightly low. I havnt measured it accurately or anything other than by eye. It defineatly isnt too high tho.

 

Have the shaft balanced.
Replace the u-joints and the centering ball.

 

Hes tried different shafts same result

 

Is the SYE a hack & tap? It may be off.

 

Oops...missed that.

Have you checked your tranny and motor mounts?

 

Is it possible shafts to long seeing how your only on 3 inch lift ?

 

Nope, not a H&T.

 

Oh.