Macknjack

ok so i picked up my 2000 cherokee classic about 3 weeks ago. has the 4.0 automatic np231. the following weekend i lifted it. I went with a 4.5" Rough Country short arm kit. I installed front and rear lifts and then the transfer case drop.

during the test drive afterwards i have a vibration from about 15-35 mph. I pulled the front driveline and it stopped. So i replaced the u joints and the centering ball in the front driveline. Reinstalled and the vibration was still there! So today i pulled out the t case drop, vibration worse. Put it back and added a few washers, vibration not as bad but still bad enough to pull the driveline.

So as of now i have pulled the driveline out. Does anyone have any other suggestions?

Right now I have a low pinion 30 so I am going to get a high pinion 30 this weekend. dont really want to do the swap if that isn't it but i dont know what else to do next.

Stitch

Did you adjust the lower control arms? At the axle there are cam bolts you need to adjust the pinion angle. Gotta keep it as straight as possible. Also, if your uppers are adjustable give them a few turns.

You could also drop in another CV drive shaft for the front.

NorCalJeep

Did you get it realigned?

Macknjack

i didn't adjust anything with the axle position, i didn't notice anything. i'll check that out.

do you mean try a different front driveline?

Trev1006

Also the angles on the u joints needs to match for no vibes. Aka...if the t case front yoke points down at 5 degree the axle yoke needs to point up at 5 degree. If the front driveshaft being out made it go away I would say thats it. Use a angle finder from Lowe's to verify your matched. If not that will cause bad vibes. Did a shop do this work? If they didn't match the angles they dont know what the f they are doing. Remember max 7 degree per joint.

Macknjack

yes that was my test drive, lol. tire shop isn't to far from the house.

I installed the lift. i will have to do my home work on the angles. How do i adjust this?

so i just went and looked to refresh my memory, all of the bolts i pulled out were straight bolts, no cams on them. The only thing that looks adjustable is the lca mount on the chassis. They are slid all the way to the back of the hanger. I would think pushing that towards the front the chassis would make the yoke point more towards the ground? i would think it needs to point more up

Stitch

I don't think a front end alignment is going to fix the problem. It's the pinion angle the toe and camber would come into play with tire wear and pulling of the wheel. Also, to center the axles under the vehicle.

Trev1006

You adjust the angles with adjustable control arms.

Macknjack

I wouldn't think it is the alignment. only the camber on one side was out. tried to sell me adjustable ball joints but 1 degree of camber is not greatly going to affect tire wear. caster and toe were ok as well. I can get the numbers if someone wants them for any idea of what it could be.

Trev1006

You dont want the angle to be straight, u want it to match the t case like I said.

Macknjack

gotcha. which i do not have. any other alternative?

Stitch

You should see small lines maybe 3 or 4 little near the bolt head. The hole is oblong. It's only for small adjustment. 3-5*

Trev1006

I typed it wrong the first time, if the t case points down at 5 degree ish the axle needs to point down about 5 degree not up at 5 degree. If you dont have an angle finder slightly down is ok. I set up all mine like this and have no vibes. I also worked at a shop for along time and this is how we did it. They need to be close to matching.

Trev1006

If u have a cammed bolt you can adjust it that way but not all aftermarket control arms have them. How long bolt to bolt are your lowers. Also do.you have the stock upper? Are your control arms straight or bend slightly?

Macknjack

straight bolt, no cam. I"ll measure the lowers. Stock upper arms. Lowers are slightly bent. (rough country arms)