Vibrations after OME/SYE install

[reiner00XJ]

2000 XJ Sport, 1”up country, - rear swaybar. D 35, with Trac-lok. ABS. Stock tires.
Afterm. installs: JKS adjust trackbar. Steering brace. Borgeson steering shaft.
Original setup had slight drive train vibrations from 69 to 74 mph. Almost none after trackbar installation.

Had 2.5“ OME, medium lift installed. OME shocks and steering stabilizer. At the same time new
front and rear driveshaft from Tom Wood and the HD NP 231 SYE from JB conversions. Aligned.
Result: Minor rumbling drive train vibration from 20 to 35 mph. Smooth, noisy from 37 to 68 mph Very noisy, stronger vibrations from 69 to 75 mph. Took HD TC out. (Overkill and too noisy for my purposes, source of vibes?) Had Advance Adapter SYE installed in original NV 231. Assembled. Result: Minor
rumbling drivetrain vibration from 20 to 35 mph. Smooth, quiet to 68 mph. Noise and vibrations from
69 all the way to 80 mph. (Didn’t go further.) Almost as bad as with the HD TC.

Has anyone had similar problems and found a solution? Or, would anyone know what could be at fault?. What corrections to make?

Sorry so long. Any help is greatly appreciated,
reiner00XJ member 264

 

[Nick]

This may be a stupid question as you seem to have thought of everything from the set up you've listed, but is there a chance you need to shim the rear axle a degree or two?

 

[Rawbrown]

I will second that...

double check your pinion angle. it needs to point no more than 1-2º down from the driveshaft. you can;'t jsut install an SYE and CV driveshaft and call it a day. the pinion needs to be rotated up.

 

[DMMcG]

<whisper> get longer shackles </whisper>.

They'll point your pinion up a touch, and help those rear springs flex like they're meant to. Doesn't mean that you won't have to measure your pinion angle, but you may not need shims at all with the new shackles.

 

[xjhm]

<whisper> get longer shackles </whisper>.

They'll point your pinion up a touch, and help those rear springs flex like they're meant to. Doesn't mean that you won't have to measure your pinion angle, but you may not need shims at all with the new shackles.

i know their is no one answer for the shimming of the rear question.......but what shackles have you guys used with possibly a 3 1/2" spring that may get the axle close........also how much is too much when raising via shackle?

 

[Nick]

xjhm-

I to have the OME set up, I think the springs you are talking about are the heavy duty ones that give you 3" though the non HD that I have seem to give me that as well, and have ORGS ACOS up front and RRO 1.5" Shackles in the back. I have the RE hack-n-tap SYE and believe that I am starting to get some vibrations now at 55 after about 3000miles on the setup. I believe it is a matter of trial and error and that there is no set formula for lift height and angles with the xj, an example being that some people seem to be fortunate enough to lift their xj 4.5" with no vibrations while some unfortunate sap who puts a BB on needs an sye. Like the other two responders mentioned, check the pinion angle. Keep me posted on how it goes and the solution as I'm on the same path as you.

 

[DMMcG]

I have an OME suspension.

Front: 934 ZJ coils, with a 2" poly spacer on top (with the stock rubber grommet as well).

Rear: JC1A with the full length JCXL add-a-leaf, plus a 1.5" greaseable shackle from Rusty's.

My XJ is a '98 with the auto and NP242 t-case. I've subbed in a 231 tail-cone, and have Tom Wood's SYE "kit" and drive-shaft. My suspension is approx 4" over stock, though it'd be more without the weight of the bumpers/winch/spare tire/tools etc. etc.

I have some driveline vibes at 85mph, and virtually never drive that fast - was on the highway and forgot myself: started to feel like it did before the SYE kit, and I noted I was travelling too fast.

My pinion angle is as good as I could hope for without any shims at all. It's about 2* down from pointing exactly at the t-case.