RobA

Hi i have a 87 Jeep Cherokee Wagoneer 4.0L
Problem :vibration after 70kmph and dont change at 110-120kmph
dont feel it in wheel or body shake can feel it threw floor like a growling sound.
I found that passenger side motor mount nuts where missing replaced and tightened that didnt fix i see that one bolt was lose on trans crossmember but still have it.ujoints have slight wear the weights are on the drive shafts
harmonic balancer looks good too
Any one have any idea im running out thanks

Spacemonkey6401

With the motor mount nuts missing and the bold being in there loose, it's possible that the motor mounts, depending on what kind they are, are bad. I know on Chevy's that there is usually a piece of rubber that they run through, and if it's loose where it could vibrate like that then it will eat the rubber. An easy way to check your motor mounts is to have someone start the car and someone else watch the motor, have the person in the car shift it from drive, neutral, and reverse and see if the motor hops, if it does you need to replace the motor mounts.

U joints could be the problem also. Do you hear a clank when putting it in reverse or drive, if so you should replace the ujoints.

Check for dents in your driveshaft, it's a possibility that there is a dent in it and it's causing it to shake.

I know you say it doesn't feel like wheels, but do you have your tires balanced? Have you recently had a flat fixed or anything like that?

That's all I can think of, I might be right, I might be wrong, but they are ideas.

RobA

well i had wife load motor up in drive and reverse see if motor jumps seems tight in drive and reverse seems to move a little more ,i had a look at ujoints to see if there moving while under load they looked good the rear ujoint has a slight clunk im going to change it but dont think its the problem growel is something iv never come across. i did repair the one pass front tire with a plug on inside edge looked saveable the wieghts are missing from that rim but would that make it growel tires are fairly new also

RobA

could it be a loose flywheel when we go to start it once in a while we get a grind like starter binding with flywheel

Volt-Schwibe

it's possible the flywheel is loose, or perhaps the bolts that connect the torque converter to it.

could be the bolts connecting the transmission to the engine, and it could even be a motor mount / trans mount.

if it's none of those, then it makes me suspect a loose bushing in the transmission, where the torque converter sticks into it.

i think it's called the front pump bushing.

RobA

well i looked at flywheel no cracks from what could see from removing inspection plate i spun flywheel looked fine i did notice thou on the trans mount the peice thats conected to the exshust from the mount was broke and the rubber looks like it stretched up and i can grab hold trans yoke and shake fairly easy i think ima try trans mount cause i am getting lot vibration under my seat
hope this works this site is proving to be very helpfull

RobA

should u be able to see the weight on the flywheel from the inspestion cover side i seen 2 little blobs of weld but no wieght there Thanks

Midnight Tech

According to my ATP catalog here at work, that flywheel does not have a weight on it.

RobA

could explain why its not there then :) thankyou for leting me know
iv ordered motor mounts im leaning to that now after looking at my 90 jeep
try that if its that ill post and close