I have a vibration that starts around sixty-five in continues to get worse after that it never leves out or goes away after 65. The jeep has 3in RC lift 235/75/15 tires. rear ds has new ujoints checked the double cardegan joint in the front not for if I spelled that right but it checked out okay it has an 1in tcase drop on it when I put that on it seemed to help. the tires have been balenced and rotated and the jeep has been aligned since lift was installed. To me it sounds like the noise/vibration is coming from the transmission/T-case area. any help would be greatly appriciated.

 

Check your t case mount and see if its good.

 

Brand new a month ago

 

Try wiggling you rear drive shaft at the t case and see if there is any side play. Might need a new bushing for the drive shaft. Also night be a wheel bearing.

 

Sounds like it started when the lift was installed. Also sounds like you've covered most of the bases. PORC sells a pretty cheap SYE.

 

please check T-case fluid and sounds like the chain has alot of play mine did the exact same thing before the t-case EXPLODED.

 

I just took the front drive shaft off and it is gone does that mean it is the double cardan joint it seems to have a couple of hard spots in it and fairly stiff. Is there any chance it is something in the front end.

 

It does have a little side to side play. Probably a 1/32nd. new bushing in the t-case how hard is that and can you buy just the bushing or do you have to buy the whle rebuild kit?

 

They sell these at parts stores, just pop off the tail end of the transfer case with the rear end raised up a bit and it's in side of the housing. Try lowering the transfer case another 1/2" I did and seamed to really help.

 

The stuff in the front end still spins even when you take the front driveshaft off as far as I know. So the answer must lie in the front driveshaft. You could fill the slip joint up with grease through the zerk fitting and see if that quiets it down. That will let you know if the 1/32" slop you have noted is too much. If it doesn't quiet it down, then yes maybe a Cardan joint and/or u-joints would be next on the list. What do the u-joints look like when you pull the end caps off? Are they bone dry?
Did this start right after you installed the lift?
Mike

 

How hard is it to replace the ujoints in the cardan joint.

 

I replaced the U-joints in the double cardan joint put the driveshaft back on the jeep took it for a drive and it was back again didnt help at all

 

Did you replace the cardan joint itself?

 

The only thing I replaced was the ujoints. once i put it back together the joint moved alot smoother. when you talk about the carden joint your referring to the sealed ball that rolls with the spring in the middle of it. If so i did not replace that.

 

I crawled back under the Jeep and checked the driveshaft out again. the output shaft on the front of the t-case moves a little. I took the ds off again and turned the shaft and sounded like an old worn out bearing I'm assuming the t-case is going out any suggestions.