roccov12345

Hi all

Looking for some help here because I'm just about at my whits end with this entire project. I have a 97 Cherokee Sport with AX-15, NP 231 and 8.25 rear. I installed the lift in my apartment complex parking lot by myself about 2 weekends ago and low and behold the truck vibrates terribly. RC 3" Series 2 kit came with coil springs, lower fixed arms, shocks and full rear leaf packs.

Before you recommend the search button, I've searched endlessly for info and insight from the internet, mechanics, rough country and multiple other vendors. I've learned a great deal about the geometry of the suspension in that time, I just need a helping hand to pick a remedy.

So.... my vibrations can be felt from a get go, very slight, throughout 25-40 mph at it's worse and significant throughout the 40-70 range.

I measured my angles last night and I'm coming up with 5 deg at the transfer case and 12 degree at the rear pinion yolk. Big difference in angles considering the yolks should be parallel with a single cardon driveshaft.

I spoke to rough country who was absolutely no help. All they could say was that they've never heard anyone with a 3" lift having vibration problems. (ok bs)

The truck has been aligned. Both Toe in, castor and camber values were in spec.

I've changed the rear DS ujoints with no change to the vibration.

I initially wanted to go with the Iron Rock Off Road Hack n Tap because I don't like the changed angles of the engine/tranny with the TC Drop spacer. The problem is I don't think the driveshaft is going to work with that little amount of lift. I'm afraid the DS will bottom out. I guess I won't know for sure until I attempt it but it would be nice to know if anyone else has run into this issue.

She looks so pretty I just want to get her back on the road.

samurai

im getting a similar problem to you,i have the rc 3" lift,my rear UJs are fine but the driveshaft angle is way to acute,and mines moved quite away out of the TC,the driveshaft guy at the shop seems to think the TC drop will cure the problem,there is no way it could run right at that angle,im gonna fit it this week..cause its spoiling my truck..just a thought though have those wheels been correctly balanced? or maybe you have one out of round?..

Cane

Start with a t-case drop, if it doesn't work go with a SYE. You said it yourself, you want it back on the road, so might aswell try all the possibilities.

https://www.cherokeeforum.com/f67/3-...e-drop-102277/

https://www.cherokeeforum.com/f67/3-...-vibes-128375/

roccov12345

I think the TC drop might help some but if your pinion angle is as out as mine is, I'm almost certain you'll have to shim as well. There's no way in my case the 1 inch tc drop will make up for almost 7-8.5 degree change. Same outcome with my stock wheels. New wheels are balanced.

roccov12345

I'd really rather dish out the cash and go straight to SYE but I'm not sure there is a driveshaft out that will work with this lift......? Anyone?

sreeb

How much rear lift do you actually have?

Measure between the top of the rear axle and the frame where the bumpstop mounts. Subtract 6".

bruni86xj

thats crazy im up 5" on my 98 classic and only get slight vibes without the tcase drop, i would tcase drop it and shim the rear axle. they're on amazon for like 15 bucks i think

exjay1027

are you sure it's a driveline vibe and not a steering component?

roccov12345

This will tell me what my actual lift was after the kit? I'm assuming 6 is the stock difference?

bruni86xj

mayber try to balance you tires with bbs i just did and they are smoother than ever http://www.innovativebalancing.com/BigTirechart.htm

edit: i was getting a decent amount of vibes before even dw

freegdr

Pictures of ds will really help get a better idea of aangles.

roccov12345

Sitting in the cab, the vibes are definitely coming from rear of the front seats. I guess I should pull the rear shaft to see if vibes are still there? Is that just a matter of pulling the shaft and driving in 4 hi?


On another note. RC told me I would have no problems with my original stock track bar but this was also wrong. Utilizing the stock track bar and bolt hole, my passenger spring was straight mangled in the spring perch. The front axle was shifted almost an inch and a quarter to the driver's side. Bought a iron rock off road track bar and all is better.

roccov12345

I got the same vibes with stock tires/wheels before I swapped on the 32's and cragars. No difference in vibes between the two, just more grumbling from the MTr's

bruni86xj

yeah i was at stock tires and just threw on the 31s lastnight, plus with the bbs ya dont have to worry about when your rims are muddy it being off balance or throwin weights on trails, plus mountin em up yourself and throwin in bbs is alot cheaper than payin 15-20 bucks each tire for mount and balance

roccov12345

I'll snap a pic tonight, angle measurements were TC=5 / Rear Pinion Yolk = 12.