first sec. of accel. vibrations....?

I have an 88 Limited with 3" of lift. I did the lift about 2 months ago, but have just recently (within last 2 weeks) developed a bit of a vibe for the first second of acceleration from a stop. If I let the Jeep get rollin (automatic) before gassin it then it doesnt happen, just if I gas it normally (not mashing the pedal, just "normal"). I have new motor and tranny mounts to go in, just figured I'd put it out there in hopes someone else has defeated this one before :roll:
thanks

I just dealt with same problem. Driveshaft U joint. Check the rear. If you got a locker in the front that causes ur front to turn, check that too.

Double check the tightness of your u-bolts on the axle. Mine backed off and let the spring pads on the axle get bent. Or the spring pads bent and let the u-bolts feel loose. Just something else to check.

Daryl

CUxj88 said:

I just dealt with same problem. Driveshaft U joint. Check the rear. If you got a locker in the front that causes ur front to turn, check that too.

Click to expand...

do you mean of the ujoints might be shot? I haven't ever replaced one, but I am pretty mechanical (graduated from auto tech program) how difficult is it really? and also is there a heavy duty one that I can put in there?
thanks again :guitar:

got under the jeep and double checked the torque on the axle ubolts... all still fine, no play that I could distinguish in the shaft or ujoints. any idea what this vibe might be? could it be a problem with driveline angle? like pinion rotating on accel.? when i pulled and pushed on the driveshaft to check the ujoints the tail of the trans was moving around a bit more than I wouldve expected. I have to swap in my motor and trans mounts and see if it gets better.

Maybe you have tranny problems. Sounds to me like the torque converter may have a play in things. When is the last time your tranny fluid was changed?

Anyone agree?

I'd check to slip yoke for spline engagement.

I looked into cheap ways to fix probs first, I checked to make sure my tires had not thrown a wheel weight.

Then I lifted truck up and checked for play in wheel bearings/ball joints.

sorry, i think i skipped this, I checked U bolts every 100 miles after installing my lift, until I hit 500, but I still check them any chance I get, they are nice and snug and have been for a while now.

Then I pull off rear to get a closer took at some "pay attention to" areas, one of the caps on the rear most u joint was like cracked up the top and it was like almost splitting open. It was weird because I checked the shaft before and it seemed fine no excessive play. I shaked shaft up and down etc. to see if U joint moved. anyway it was in the area covered by the yoke strap. I replaced it as soon as i saw the crack and then took it for a spin see how it handeled. It was fine no more vibrations. You can check to see if it's the front or rear shaft too casuing them by driving without front or rear seperately, just remember to cover up the rear with some kinda of improvised solution to keep t case fliud from puking out

how would i check spline engagement? and by tranny fluid puking out you mean if i pull the shaft? i was wondering if i would lose any fluid... the trans fluid is maybe 6 months old i believe (still bright red and clean), the previous owner had an aux tranny cooler plumbed and new fluid put in. i think i might just replace the ujoints because theyre pretty cheap, and i would feel better knowing they were new anyways. if pull out the shaft while parked to do the joints will i lose trans fluid? thanks for all the sugestions, i'm just checkin pne by one..........
you guys rock :worship:

when I lifted my first XJ, within a hundred miles the rear u-joint self destructed, I'd say change it no matter what, it's only $10-15 and half hour of work.

other than that, you may be getting axle wrap which causes the driveline angles to be off when it wraps up, you could get some 2 degree shims and put them in (fat end forward) to rotate the pinion down a little.

Sounds like a U-joint to me...if it is a u-joint be sure to check yoke to joint clearance at full droop...if the joint binds on the yoke(s), it will destroy the joint in short order...you can clearance the yoke(s) with a die grinder if required..

My truck has a similar vibe when barely moving on pavement...but it's the lugs on the tires

I'm going to change out both ujoints in the rear and see where that gets me. When I pull the shaft out of the rear of the trans will fluid come out, and if so how much? thanks for all the hints and I'll consider the shims....
have a good one!