The other nite driving home, I get onto the freeway, kick it into 5th gear and just cruzin along. I go to let off the gas and all of a sudden it feels like my jeep is going to raddle apart. Its the most violent shacking rumbling sound Ive ever heard, and it only does this when in 5th gear and let it coast, like letting off the gas and not engaging the clutch.

Now if I push in the clutch while in 5th gear, no issue, but when in gear and costing, it wants to raddle violently..

Any thoughts as to what this might be?

94 4x4 5 speed man.

 

I'm in the same boat. 5speed; I've lifted it 3 inches so I'm hoping thats the problem

 

Mine is doing sort of the same thing also, just out of the blue it started acting up. It sort of sounds like i'm driving on a flat tire, originally in was only doing it in 3rd gear while accelerating, now its doing it in all gears no matter weather accelerating or coasting. This is jus tover a 3 day period... It completely goes away when I push the clutch in and coasts smoothly.

Mine is a 97 cherokee, 4.0, 4x4, 5 speed. 3" lift and 31's...

 

Check front and rear u joints, look for "powdered rust" or play around the joint. Might not be the problem, but a good starting point.

 

@nbaker - yup same thing, push in the clutch and its fine, only seems to do it in 5th gear.

@tiwvr1 - think i will replace the rear u joints as a start to see if thats the issue. for $9 a pop at autozone, easy cheap replacement. plus its prolly about time as the jeep does have over 230K on it and i dont think they have ever been replaced before.

oh, and mines all stock suspension

 

I had this problem in a stock 90 xj automatic but if I was doing 75 on the highway and let off the gas it would rumble something fierce. Actually rattled my rear view off but anyway it was the rear output shaft on my t case. Only 160k but I replaced t case and it drove beautifully.

 

Easy way to check if it's that is remove rear drive shaft and see if you can shake the rear output shaft. Mine had a full inch of play. hope this helps.

 

I pulled the rear drive shaft out of mine after work tonight. The rear U joint was toast. I put it in 4 Hi and took a spin around the block, and my wobble was gone so I believe I have found the problem!! So now I just have to figure out how to get the U joint off of the back of the rear drive shaft...

 

Well good thing you found the problem. There should be clips you use needle nose pliers on pull the clips and they should slide out.

 

@nbaker - sweetness!!! happy to hear it was only your u-joint, gives me hope that's all that's wrong with mine as well.

@99jeeprokee - thanks for the tip, will check that out tonight when I get home.

 

No problem that was my issue doesn't mean it's your. But I bought a used t case for 75 changed fluid and then that was it.

 

should the rear output shaft have NO play in it what so ever? the u joints in mine seem good but when i was under there pushing and pullin on the drive shaft i felt some play in it, near the output shaft.

 

last night i swapped out the transfer case in hopes of eliminating this issue. now when i start up the jeep or turn it off i have this really bad vibration, as if the transmission has something wrong with it or something. i would describe the noise as a rumble, as if a motor mount was busted, but i checked those and they are all good. so what would cause a horrible vibration/rumble sound in the floor board when starting and turning the jeep off. when i turn the jeep off, i notice the tcase kind of shakes so like its lose or something, but all the bolts are really tight. idk im lost....

 

The rumble is still there after replacing the clutch, rear u joints and TC. I lifted the back end up off the ground and started it in 5th gear and got out and checked the drive line and it didnt seem like it was bent. Tonight im going to pull the rear drive shaft and see what happens in 4wheel drive to see if the rumble goes away. i did notice a lwhat seemed to be a little play near the rear end, but i dont know if that would be the cause. so at this point im completely stumped...like i said it only does the rumble when im in 5th gear and i take my foot of the gas to coast while its still in gear.