need help ASAP please

hey guys, I just had a question I wanted to see if you could help me with. I have a 93 Cherokee and it has a 3" rough country lift on it, and 31" bfg all's. I've had the lift for probalby close to two years now, and ever since I got it, its had a small vibration at about 48-54 mph. It was tolerable though so I didnt do anything about it. However lately for some reason the vib has gotten pretty bad. At about that speed it starts to vibrate actually pretty hard. Could this be some form of death wobble? I have the stock driveshaft, no shims or tc drop, could it be from this, or would it be something in the steering or alignment? Thanks a lot for your help, I need to get this figured out before it gets out of hand.

if it is at the same speed but just feels worse it sounds like the rear shaft u-joints have finaly started to fail. u-joints are cheep and easy to fix!! there are plenty of write ups about doing joints so i'll let you find that but other than that u might want to try a t-case drop to get rid of the old vibes.

Sounds like a harmonic at first (nothing can be done about those...) but since you're seeing it get worse - and you're asking for advice (and I just got some in,) here's a few things I'd look at.

Check the wheels inside and out. Make sure you don't have a small "clean spot" that looks like somehwere a wheel weight might have gone. It's possible to lose a small one and have it seem like a BIG problem!

If you have "lifetime balance" on your tyres - take 'em in and have them checked. Can't hurt.

Jack up the front end, and check ball joints and steering linkage for freeplay. Ball joints will almost universally cause a shimmy of some sort when worn, and worn steering linkage can also make it seel like a bad shimmy (since there's nothing holding your steering tyres in place but the damper.) Check ball joints (and several other components) by grabbing the wheel and shaking it while it's up in the air. If there is excessive motion, have someone watch everything while you shake again to isolate the fault (that's usually how I end up doing it.) The steering linkage can be checked on teh ground by trying to move the drag link back and forth by hand, or in the air the same way by having someone hold the steering wheel so it won't move. This will point up worn tie rod ends.

I'd also go thru all the rubber bushings and make sure none are "pounded out," cracked, chipped, or otherwise AFU.

Most front end problems are caused by worn parts - so that's the first logical place to look. If you drive anything like I do (I tend to not care about speed bumps, kerbs, carpark barriers, and suchlike) you'll go thru parts. Off-road use can also be tough on front end parts, so regular inspections are ALWAYS a good idea.

5-90

Jake Toney said:

hey guys, I just had a question I wanted to see if you could help me with. I have a 93 Cherokee and it has a 3" rough country lift on it, and 31" bfg all's. I've had the lift for probalby close to two years now, and ever since I got it, its had a small vibration at about 48-54 mph. It was tolerable though so I didnt do anything about it. However lately for some reason the vib has gotten pretty bad. At about that speed it starts to vibrate actually pretty hard. Could this be some form of death wobble? I have the stock driveshaft, no shims or tc drop, could it be from this, or would it be something in the steering or alignment? Thanks a lot for your help, I need to get this figured out before it gets out of hand.

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how are your transmission and motor mounts looking?

thanks for your help so far guys. my tires probably are not real balanced, havent had them done for a while, but i just didnt think that they would cause such a severe wobble, and the only other thing is that when i first got the lift it did the same thing and i got the tires at the same time, so im sure they were balanced then. im pretty sure my ball joints are ok, but ill double check. im not sure about the steering linkage. somebody at a local fourwheel drive shop told me its probably my driveshaft, just from me explaining it to him, but i wasnt sure. if it is my driveshaft, whats the best option for me without maybe dumping all the money into an sye. Maybe just a drop transfer case (but id hate to lose the clearence). Do you think shims would help. Thanks again guys.

Jake Toney said:

if it is my driveshaft, whats the best option for me without maybe dumping all the money into an sye. Maybe just a drop transfer case (but id hate to lose the clearence). Do you think shims would help. Thanks again guys.

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Well, first check and fix any items mentioned above. Since you had small issues only maybe they were just a prelude to current problem? Once you get back to the point where you were at or better, then start looking at what else needs to be done.

Btw, tires that are not balanced can give yo ua really squirrly ride, so if you haven't had them balanced in a while, definately start with that and then go through the items that are easy to test/fix/replace.

Vibrations =Driveshaft,Death Wobble=Un-controlable shaking of the front wheels/steering wheel."And you would know DW if you had it!!!!!!!!!!!!!

i'd check DS ujoints first then move to tran mounts... if it vibed a little in the beginning after the lift was installed, you should of put some sort of tc drop, or at least some degree shims*

HTH
brandon
i'm thinking most likely ujoints though. definitely get some shims or tc drop though, they're not expensive at all and you can easily make ur own tc drop

check u joints, steering stabalizer, tire balance and check for uneven wear. happened to me.

Ignore your driveshaft, u-joints and motor mounts and anyone who tells you to check them. The 48 - 54 MPH clue guarantees this to be tire/wheel related. Follow up with what 5-90 mentioned. The slop in your steering/front suspension has increased since the install, allowing the crummy tires to start dancing.


rotate and balance your tires.
make sure to get a dynamic balance
check castor: should be around 5 degrees or so
replace steering stabilizer
check for loose steering and front suspension parts & worn rubber bushings

MaXJohnson said:

Ignore your driveshaft, u-joints and motor mounts and anyone who tells you to check them. The 48 - 54 MPH clue guarantees this to be tire/wheel related. Follow up with what 5-90 mentioned. The slop in your steering/front suspension has increased since the install, allowing the crummy tires to start dancing.


rotate and balance your tires.
make sure to get a dynamic balance
check castor: should be around 5 degrees or so
replace steering stabilizer
check for loose steering and front suspension parts & worn rubber bushings

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I didn't see in any of the original post where the guy said he had slop in his steering or had a shimmy, thought he said he had vibes. It should be pretty easy to tell if it's a vibe from behind the driver's seat(driveshaft problem) or a shimmy from the front(suspension/steering/tire problem). Go from there . After I put on my 3" lift had vibes at 45mph from the rear. 1" trans. case drop and 3 degree shims got rid of them. If it is vibes from the driveshaft don't ignore the U-joints, replace them with greasable ones if they're not on there already.

SteelblueSteve said:

I didn't see in any of the original post where the guy said he had slop in his steering or had a shimmy, thought he said he had vibes.

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So, you're guessing a '93 with a 3" lift has tight steering? Good guess.

SteelblueSteve said:

It should be pretty easy to tell if it's a vibe from behind the driver's seat(driveshaft problem) or a shimmy from the front(suspension/steering/tire problem).

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It is easy...
either your butt tickles or the steering wheel shakes

SteelblueSteve said:

Go from there . After I put on my 3" lift had vibes at 45mph from the rear. 1" trans. case drop and 3 degree shims got rid of them.

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Sounds like you had a problem with u-joint angles. :thumbup:

SteelblueSteve said:

If it is vibes from the driveshaft don't ignore the U-joints, replace them with greasable ones if they're not on there already.

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But, since it's not vibes from the driveshaft, don't send him on a wild goose chase.

ya just following up on you guys posts, thanks by the way, ya as maxjohnson said, my steering wheel definately does shake, pretty badly actually. basically the whole jeep shakes back and forth pretty bad, but including the steering wheel. So i guess from what you guys are sayn it must be something with my steering/suspension in the front or my tires.

sounds like its out of ballence to me. when was the last time you had your tires ballenced? Hopefully that is all it is. that will be a cheap-n-easy fix. just get them ballenced. But i would consider shiming the rear end 3 degrees to get rid of the vibes you had originaly. beside that it will help ujoints last longer. Shims are cheap. Its worth it to shim in my opinion. I really doubt you need a tcase drop. Good luck.

Check the slip yoke coming out of your transfercase. I believe that on 92 and newer you have to either drop the TC or get a SYE kit for anything over 2". Grab the yoke coming out of the back of the transfer case and see if you can move it up and down. There should be very little play up and down. Also see how far the yoke had pulled out of the transercase. If it's come out too far, you end up with the yoke riding on the end of the shaft. Not on the shaft it's self. For a cheap fix you can get a longer yoke and that should help quite a bit but the problem will still exist. Had it happen on my 90 and it felt like the whole jeep was going to come apart. Had the SYE install and my vibe problems went bye-bye.

Laters.........Mikey

Another free and easy check is to rotate the tires. I had the same problem, it came on quickly and got worse. I rotated the tires and the symptoms went away.

cool, so i guess ill start out with the tires, since its easy and cheap, and probably do that tomarrow. Just one question though, if its the tires, is that normal for it to vib/shake mainly at a certain point (say my 48-54 mph or so) rather than it doing it basically at any higher speeds?

MaXJohnson said:

So, you're guessing a '93 with a 3" lift has tight steering? Good guess.
Didn''t guess at anything, went by the guys post which said nothing about steering. But since now he says it does I guess you had the good guess.

It is easy...
either your butt tickles or the steering wheel shakes
I feel nothing near my butt excect my hemoroids, mainly from driving Jeep Cherokees.

Sounds like you had a problem with u-joint angles. :thumbup:
Yes, and nothing Prep. H couldn't take care of.

But, since it's not vibes from the driveshaft, don't send him on a wild goose chase.

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HIND sight is 20/20(get it?)

Jake Toney said:

cool, so i guess ill start out with the tires, since its easy and cheap, and probably do that tomarrow. Just one question though, if its the tires, is that normal for it to vib/shake mainly at a certain point (say my 48-54 mph or so) rather than it doing it basically at any higher speeds?

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All I know is I had the vibes at the same speed you're mentioning, felt like I was going over the stutter bumps they put on some highway shoulders , higher or lower speed I had no vibes. Also had death wobble earlier on and as someone said earlier it's obvious. Longer LCA's got rid of that , corrected caster angle. The death wobble never let me get anywhere near 45 mph while I had that problem.