97-01 driveline vibes. Your solutions???

I bought a RE 3.5" SR lift, with full rear pack, and I just finished the install on my 01'. I owned a '92 and installed 2 different lifts on it over the years (Rough Country AAL and a Skyjacker AAL), I know from what I've read in other posts that the 97-01 are the worse ones for vibes, but the '92 was never this bad. I've installed a *4 shim in the rear and a 1" t-case drop and it cut the vibes in half. What's next? Is a SYE the only answer for this? Will it eliminate all the vibes? I'd just like to hear your feedback and experiences.



I've installed an extra front insulator since this was take to level it out some.

yes you will need a SYE. How bad is your front pinion ange?

In my 2000 I had way more front driveline rather than the rear.

A sye and a high pinion 30 were in order for my instance.

I honestly haven't looked at the front. I'll check it and post some #'s.

I dont want to lead you astray here, if you know that you have rear vibes then fix that first. I just want you to make sure that the vibes you are feeling are not coming from the front.

When I was at 4.5" lift my dash felt like it was going to rattle off, so I adjusted my caster, then I had major tracking issues. After I fixed the front, then I worked on the minor vibes in the rear. Fix what doesnt work first.

The '00-01 xj's have the low pinion dana 30. This is where your vibes are comin' from. The u-joints are at unequal angles. You'll have to change to a high pinion Frt. axle to rectify this. The '92's have the high pinion dana 30. Thats why you didn't experience this problem. '84-'99 Cherokee's have the high pinion D-30, so finding one at a wrecker is a viable option. Good luck!

Fixes for Low Pinion vibrations, added stress to drive shaft components, and pinion wear after lifts of more than 3" .

1. Swap in a high pinion 30 or 44

2. Adjust caster and hope that you lose the vibes, and can still steer it down the road in a straight line.

3. Remove drive shaft until you go wheeling

4. Dana 30 Warn Front Hub conversion

5. Lengthen wheel base to make drive shaft longer, thus removing vibes.

These are all possible fixes for front driveline vibrations

Ben H said:

Fixes for Low Pinion vibrations, added stress to drive shaft components, and pinion wear after lifts of more than 3" .


2. Adjust caster and hope that you lose the vibes, and can still steer it down the road in a straight line.

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I would think you should be able to adjust caster enough on the LP D30 to fix the vibes and track nicley with only the 3" of lift. I have just under 6" of lift and I had to find a happy medium between caster, vibes and tracking. I ended up setting mine at 6.5*. Again, this is with close to 6" so I was pushing it. You can also use offset balljoints to obtain the caster you need and still make the driveline happy, but again, you shouldn't need this with only 3" of lift.

I haven't had a chance to have the alignment done yet and i plan on having that done on the way to work tonight. how does the *6.5 camber angle affect your driveability?

i'd read they put a few HP30's in the 00's but my wifes and mine both have the LP30 (i was going to rob hers). so, if the alignment dosen't help with the vibes, i'm going to pull the front drive shaft and take care of any vibes in the rear. then i'll go back to the front. i'll buy a HP30 if i have to.

thanks for the advise XJ2001

My 2000 has a hp30, and I had some nasty vibes that ended up being a lightly bent front driveshaft. I'm at 5.5" and the only vibes I get are from the rear at about 45-50mph and are very slight. Mines a 4 banger so my driveshaft it extra long out back alowing me to go this far with no SYE. My rear shaft does have lots of play at the slip joint though, so I've got a SYE in the box waiting on a good weekend.

just got the alignment done the toe was off a ton. and the tech was able to get the caster angle set to *6.6 on the right and *6.5 on the left, this helped the vibes, but not much. i'm pulling the front DS tomorrow.

You should get an SYE. I wouldn't run it on that t-case even if I couldn't feel the vibes.

And you have to be real careful about the front pinion angle. let us know how it turns out.

Wouldn't a lowered tranfer case make the front vibes worse because of the angle?

Only fix whats not working!Drop the shafts and isolate the problem.Needed to install an HD sYE kit on mine,but running a LP D30 for 7 years now at 6"!

anotherjeff said:

just got the alignment done the toe was off a ton. and the tech was able to get the caster angle set to *6.6 on the right and *6.5 on the left, this helped the vibes, but not much. i'm pulling the front DS tomorrow.

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Man, 6.5* sounds high for only 3.5" of lift. IIRC you need ROUGHLY 1* of caster for every inch of lift. By the way, you asked how my driveabilty was with my 6" lift and 6.5* caster. It is pretty dang close to stock....drives straight and tracks great.

5-7 degrees at any lift height is plenty.

Possibly a silly question, but did you replace the u-joints when you lifted? If they are worn, you'll get vibration when they start moving across the bigger angles.

Let me first say that the SYE is by far the best solution.

But...

I highly doubt the front is the cause of your vibrations. You only have 3.5" lift and the LP30 typically is okay with that. I ran mine at over 5" no problem. Think about how many people with the LP30, including TJ owners, have lifted 3.5" or more. How many of them have front driveline issues at that height? So to assume right off that the front is the problem is not very wise. But if you really think it is, pull the driveshaft and see. No harm no foul.

What I see is your problem is you lifted 3.5", added 4* shims, and a 1" transfer case drop. Sounds like a shotgun approach... what were you trying to accomplish doing that? What was your pinion angle before and after? What you now have is the equivalent of a transfer case 2.5" above stock, roughly. I think a 4* shim might be too much for such little lift. But in reality I wouldn't have shimmed it at all since you don't have an SYE. I would have stuck with just the transfer case drop temporarily until you could afford the SYE.

So IMO you have two alternatives -

1) remove the shims and hope the TC drop alone does it for you (no guarantees) or,

2) remove the transfer case drop and install a SYE and CV driveshaft. Good thing is - you already have the shims installed which is what you need with this setup. And the 4* shim is a good guess if you don't want to measure.

2001XJ said:

Man, 6.5* sounds high for only 3.5" of lift. IIRC you need ROUGHLY 1* of caster for every inch of lift. By the way, you asked how my driveabilty was with my 6" lift and 6.5* caster. It is pretty dang close to stock....drives straight and tracks great.

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This is not correct. If it was, stock XJs would come with a caster setting of zero... You should try and keep the caster within factory specs regardless of how much lift it has. Factory specs are between 5.25 and 8.5 degrees with a preferred setting of 7 degrees.

EricsXJ said:

This is not correct. If it was, stock XJs would come with a caster setting of zero... You should try and keep the caster within factory specs regardless of how much lift it has. Factory specs are between 5.25 and 8.5 degrees with a preferred setting of 7 degrees.

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Ooops, my fault then. I thought I read or was told that rough guideline.

2001XJ said:

Man, 6.5* sounds high for only 3.5" of lift. IIRC you need ROUGHLY 1* of caster for every inch of lift. By the way, you asked how my driveabilty was with my 6" lift and 6.5* caster. It is pretty dang close to stock....drives straight and tracks great.

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He has more than 3.5" of actual lift.

My old 2000 had minor front vibes, but the rear was sickening, good thing an SYE was on its way.