Calling all owners of 00-01 XJ's...

W/ a 3" lift or taller, ive searched and saw the LP30's in these years are prone to vibes after 3", and they also have the 0331 heads that crack w/ higher mileage. I'm trying to get first hand experience w/ any of this b/c 98 and 99 models w/ the HP30 and diff. head are far and few between in descent shape. Main question is this will be my daily driver, i'm lookin to spend no more than $6,000, preferably less than 100k on the clock, how many of you notice vibes after a 3" lift, and how likely is it that they ALL need head work due to the cracking 0331? Thanks for any info.

Mine had about 5" on 31's and I never noticed a particular vibe from the front axle. But then again, it was a Jeep with five inches and 31's so you kinda expect some vibs. But no, nothing noticeable. And I've never had any issues w/the head either. Had a piston skirt seperate but that's not year specific. That's what happens when you run at 300+ degrees w/out any coolant :banghead:

I have an 01' and have a 3 inch lift with 32's. I had really bad vibes before I installed the new track bar. Also once I got the 32's it also helped a lot but that might have just been that the stock tires were out of balance. But now I have very minimal vibes at 45 and a little at 68-70 but it isn't bad. I also have 98K miles and have had no problems with the head.

Good Luck

I have an '01 with an RE 4.5 SF kit and TeraFlex HD SYE and on 33's. Run smooth as can be even highway speeds of 75 - 80.

Josh

i got an 00 with a re 4.5 sf 31's no sye and 160k on the clock put 60+ miles on it a day and the only issue i had was a rear ujoint was toast after 10k of haveing the lift on but i dont notice any vibes

I have an '01 with a BDS 4.5" lift, no vibes. SYE in the back and adjustable control arms up front. Gotta adjust the castor to prevent vibes with the LP.

2000 w/ 84K, all street driven easy, no crack, no coolant loss

2000 xj with 3.5" RE lift and 31'' tires. had condiderable vibes until i dropped the transfer case 1'', added shims, and replaced all my u-joints. no SYE, vibes are very minimal now. no problems with the head, 95k.

01 Sport, 5.5" RE/TNT LA. I swapped in a HP30 from a 98, but didn't have any vibes before.

I only have 54k on mine, so no head issues yet. Keeping my fingers crossed though.

JeepXJ93 said:

W/ a 3" lift or taller, ive searched and saw the LP30's in these years are prone to vibes after 3", and they also have the 0331 heads that crack w/ higher mileage. I'm trying to get first hand experience w/ any of this b/c 98 and 99 models w/ the HP30 and diff. head are far and few between in descent shape. Main question is this will be my daily driver, i'm lookin to spend no more than $6,000, preferably less than 100k on the clock, how many of you notice vibes after a 3" lift, and how likely is it that they ALL need head work due to the cracking 0331? Thanks for any info.

Click to expand...

I have a 01' with an RE 4.5" and 1.5" ACOS up front with 1.5" TNT UBE's in back so I am about 6" with the LP30 and 32x11.5s on 15x8 with 4" BS. I HAVE HAD ISSUES with my front driveline. It was so bad I had to pull the front driveline, that is the only way I could drive it. I finally took it to JCR Offroad and they adjusted the caster and rebuilt the u-joints and it helped but not much. Then they had the driveline re-spun and balanced and that improved it a bit, but not much. Still got vibes something terrible and 50+mph, so bad it was shaking the whole center console. Then they replaced the transfer case output bearing and put another driveline in that only had 30,000 miles on it that was balanced and it drives acceptable now. After all of that, they still didn't really know why i was vibing. It is not smooth as glass (still get mild vibes at 70mph+) but it's as good as it's gonna get. If JCR couldn't fix it, then that is as good as it's gonna get. Jeeps are funny that way, very unique to each one. What happens to one, will be completely different in another even if it is the exact year, model, package, etc. By the way, the guys at JCR are very good to work with. They are very patient and will go above and beyond to fix whatever problem.

Here you go.....

I have a 2001 XJ Sport with OVER 300,000 miles on it. I have 3.5 JKS coil adjusters up front, 4 in Rough Country Full Springs out back, JKS Swaybar discos, JKS adjustable trackbar, holding a Dana 30 that I have replaced the "U" joints in. I have also replaced the "U" joints in the rear drive shaft, as well as ditched the wheel weights for airsoft pellets. This XJ has been in the family since new and we have kept up with the regular maint. I have no complaints. She is my DD
Remember, with jeeps, you get out of them what you put in....
Don't let 00-01 scare you. It's all in how you maintain it....
Have fun out there! :us:

01 xj, 100,000 miles. currently has 7" lift with horrible front pinion angle. no vibes from the front, ever. I've been meaning to point the pinion back up to the tcase, but I'm building a HP30 with new gears and a trutrac. formerly had RE 3.5" with fixed arms, no vibes then, either.

never had any engine block/head issues.

95% likely to need to lower the tcase after you get past 3" of lift. 99% after 4". mine was fine with 4.5" with a 1" tcase drop. horrible vibes at 7" lift and no drop, but driveable.

My '00 with 6", and 33s had HORRIBLE driveline vibes in the front, but you got a free massage from it.

My '01 with 4.5" (RE super flex kit) and 33s has no front driveline vibration. Rides nice and smooth on the highway.

'01 with arounf 7.5-8". minimal to no vibes crusing 70+mph.

Interesting responses....sounds hit or miss, like w/ any lift. I guess i will reconsider 00-01's. Dealers are asking waaaay too much though. I'll post pics as soon as i find one and begin my build. Thanks for the help guys!

I too don't think you need to be worried about buying a '00 or '01.

If you lift it and have vibes you first need to do a SYE. The LP front end should not be an issue at 3". Maybe when you get at 5" or more then yes it could give you problems. I was okay at a little over 5" but swapped in a HP30 because I wanted to spend money (gears and locker) on a better axle and I knew I'd be bumping up the lift a little more.

As far as the head cracking, I feel it is not as big a problem as many people make it out to be. If you are one of the minority that has the head crack, it will cost you a couple hundred for a new head. Unlucky maybe, but not the end of the world.

2001 with about 6 inches of lift Tera50 front/Tera60 rear, atlas II tcase, cross oversteering, 4.88 gears running 35's. Semi daily driver, three trips to Moab (2K miles round trip) one time during July (average temp 115 degrees)-no overheating, no problems/no vibes on the highway. Almost 70,000 miles currently. Just keep up with regular maintenance, have a competant shop check the driveline angles/alignment and you will be fine.

2001 with RE 3.5", but settled to a even 4" front and rear. Had mild vibrations after the lift, then got progressively worse within a week or two. It was mostly between 20-30 MPH. The vibes became terrible until the TW SYE and CV shaft. What a night and day difference with the SYE.

124k miles with no head problems. These days, just a toad behind the motorhome for camping.

I have an 01 XJ Sport in which I installed the RC 4.5" lift c/w full spring pack rear. When I originally installed it I was getting serious vibes starting at just 15mph. I pulled the front drive shaft and my vibes were completely gone. No SYE in the rear and no vibes. I looked into it and noticed the front pinion angle was very steep. It came mostly from installing the included longer lower control arms. I solved this problem on mine with some adjustable upper control arms to point my front pinion at the transfer case output.
If you are on a tight budjet you could keep both stock upper and lower control arms and have no issues.... or find a kit that comes with adjustable upper control arms.
As for the head... I've had no issues so far.

Just wanting to chime in here too. '01 3" lift no vibes. Almost 90k on odometer and no head problems, and temp has stayed very low even out rockclimbing.