lifted1994xj

Ok i am going to try my best to decribe what is happening. I have been searching for a long time and have not come up with anything.

I have a vibration when i put my jeep in reverse and hold the brake. The vibration sounds like a rumble but not like its internal you can hear it also not just feel it(sorry its the best i can come up with) The vibration seems to come from the front end but could be coming from some where else just transmitting through the body. The vibration will slightly go away if i roll and also if i turn the wheel slightly back and forth. It will also vibrate when i back up my drive way (this is more like a shudder though) This all started after i put on my lift and the first time out wheeling this was last june. and has been doing this ever since! When i shift it into drive it idles perfectly. Very smooth.

Everything that i have done...

Cleaned throttle body...it had some oil residue in it because my ccv was clogged and forcing oil through the filter and throttle body. Took valve cover off and cleaned ccv so it doesnt do that anymore. Question could it have fouled up a sensor in the throttle body making it run bad when cold? But why would it run rough only in reverse

Did both motor mounts and trans mount looks good and tight. I also have those M.O.R.E bombproof block brackets. These http://www.mountainoffroad.com/_e/Mo..._0L_engine.htm

Took belt off and started it and still did the same thing so that rules out anything that the belt runs.

Things i will do this week take out each driveshaft one at a time and see if its any of those, check the rear drums and tighten every nut and bolt front to rear.

I hope that it is not transmission related but i don't see how it could be when it changes when i turn the wheel.

Please help anything is much appreciated!

Sorry for the long explanation but wanted to describe everything thats happening.

Jeep89JV

You really should check the fluid in your Tranny/Tcase, color and level. Otherwise I'm going to tell you its a u-joint ready to go here soon.

lifted1994xj

Thanks for the quick response! I have checked the fluid and looks good a little brown but still has a red tint to it but it doesn't smell burnt. I had it service about 6,000 miles ago at a transmission shop. I will check the u joints when i look at it next. What is the best way to check those i have heard a few different ways of doing it?


I forgot to mention that it only does it when its cold. After it gets to operating temp it is fine.

Jeep89JV

Its pretty obvious to tell if a Ujoint is worn. Best route to go is jack it up and spin the wheels, listen for clicking/squeaking or any play in it.

93gc40

If it only happens when cold may be exhaust leak or crack.

lifted1994xj

I am hoping i won't have much going on after i get home from school and i will be able to work on it tomorrow for about 4 hours and i will update with anything i find.

Jeep89JV

I won't be on until the late afternoon hours since i'm workin on a project of my own for the next two days I have one. I'm plenty sure someone else will chime in to help with input/advice on what you have to update.

Good luck and lets hope its just a u-joint and not a slipping tranny

lifted1994xj

Thanks i hope not either

lifted1994xj

So I was out working on it and these are all things that i did and didn't do anything.

Tightened motor mounts (The rubber ones and the block ones), Pulled front driveshaft, and tightened bolts for exhaust at the header.

Also the coil spring will vibrate only in reverse not in any other gear.

I had my dad hold it in reverse and i put my head up in the trans tunnel on the drivers side and i can hear it very lightly so not sure if its the trans or something else in thats in that area.

I checked the trans fluid and it looked light brown, no red tint like i thought so could that mean the trans is going. There is only 6,000 miles mostly highway and 2 light wheeling trip on this fluid nothing to hardcore. I can take a picture of it if that would help.

And again thanks for all the help!

xjlimited

Is it more of a rattling or vibration? because I have a rattllee/vibration when my jeep is cold that's coming from my cat converter. have you checked that out?

lifted1994xj

It is a vibration and sometimes it likes to come on slowly when its in reverse and the brakes on. That is a good idea about the cat i will check that out.

xjlimited

while your jeep is running just tap your cat converter with a rubber mallet or something similar

Jeep89JV

What was the outcome on your ujoints, your updates appear to not show any signs that is the cause.

lifted1994xj

Sorry have not been on i have been studying for finals. The drive shaft u-joints were good don't think its the axle u-joints because they are not under power. I am thinking it is the connection between the header and the head pipe the bolts were loose so i tightened them and seemed to help a little so going to try and get in there again and tighten them down even more.

Jeep89JV

I just don't see the exhaust being the problem here, granted tightening up the mandrels helped for possible future problems though.