OME 2" / Vibe Prevention

Just brought home a OME 930/JC1B suspension for my 96 XJ. From what I've read, 96 and later Cherokees are more susceptible to vibes even with such minimal suspension lifts. Planned install date is 4/23/05.

I'm not trying to get ahead of myself, I just want to make sure I have all my ducks in a row before install. I want no vibes - not even the faintest of high-speed shudders.

1) Does anyone have any experience with vibrations on a 96 XJ/OME configuration like this?

2) Should I add degree shims during the initial install just in case? ... or should I just try without first?

3) If shims, what degree, and which direction should they be installed with a stock tcase/driveshaft configuration? ... pointy end toward the front of the Jeep, or pointy end toward the back of the Jeep?

There's always lowering the tcase, which I'm sure would be effective if need be, but that is an absolute last resort. Ground clearance is still somewhat precious with this setup.

Chris, You shoudlent need to do drop the T-case....at most perhaps a 2* shim at the rear axle. The pointy side towards the front of the Jeep. I wouldent add any shims untill you finish the lift, drive the Jeep around and let the springs settle in a little. Then check your pinion angle, if your pinion angle is OK and you dident get any vibes to begin with then leave it alone. If not then try adding a 2* shim, if that dosent do it(wich I HIGHLY doubt) then a 4* shim.

HTH,
Brandon (AKA: RENEGADE @rockcrawler.com)

You should shim only to match the front and rear u-joint angles. You will need to measure the angle to make sure what you need but I wouldn't suspect anything more than 2* with 4* at the very most.

Go to Tom Wood's Driveshaft under the Tech, and Geometry 101 (http://4xshaft.com/driveline101.html) for more info:

Cool - thanks guys. Hate to do shit twice, is all.

I'm aware of what the proper angles should be, as in the diagram, but I've never been able to eyeball that kind of thing - I think its easier to tell by seat of pants, especially since the pinion angle has a tendency to change very slightly when under load.

Heya, Brandon. LTNS. :laugh3:

Chris.. have you found another Jeep????
Trying to make PAP mid May and need a few smaller XJs/TJs/ or whatever to get a few newbies wheelin. If you can make it let me know.

Jason

Once lifted, Check that the front UJ on the rear propshaft isn't binding on full suspension drop. When I lifted my '92 XJ 3" it wouldn't even turn. This was due to the fact that the cutouts in the slip yoke casting to clear the U/joint knuckles on the end of the propshaft are too shallow and only allow half the clearence of the cutouts in the prop end which clear the knuckles on the slip yoke.
Being poor, Not having the cash for a SYE kit and not wanting to lower the T/case I considered grinding the casting to get more clearence, but didn't really want to as this would weaken the yoke.
Then I had a look at a spare prop off of a TJ in my workshop and found that the slip yoke on this had far more clearence built in allowing twice as much flex on the joint.
All I had to do was have the yoke machined where it slides into the T/case seal about an inch further up the casting so it wouldn't damage the seal when the suspension is compressed ( the whole thing is about 1/2" longer ) and it then fits straight on with no further mods. In my case I can take her up to 100 mph with no vibes and I haven't had to shim the axle, but this may have been luck as I was expecting to have to use at least 2* to get it right.

alosix said:

Chris.. have you found another Jeep????
Trying to make PAP mid May and need a few smaller XJs/TJs/ or whatever to get a few newbies wheelin. If you can make it let me know.

Click to expand...

Jason,
We've owned the XJ a couple of years now. It was our family car, but now its my DD. I'm keeping the mods nice and light.

I would love to go to PAP with you guys, but May is really a busy month. I'm afraid I won't be able to make it. Heading to OBX with my family for a week, and then heading up to NY to do a run with OK4WD. Thanks for the invite!

To actually post something relevant to the subject.

Been helping out an '01 with a rusty's 3" lift. 4 degrees was too much. 2 degrees was better, but still had a slight vibe (really picky ex ricer driving, we all think it rides like a caddy). Installed drop kit, seemed to help but now has a slight vibe when loaded so the 2 is probably too much on that lift with the drop.

So my rough guess would be 2 degrees, no drop, with 2" OME would be a good starting point.

Don't you miss upper control arms

Jason

alosix said:

Don't you miss upper control arms

Click to expand...

Indeed. In fact, I sorely miss my whole damn TJ ... but I love my (3rd) Cherokee too. Its about a gazillion times more practical for me - especially since I procreate.