Since getting a small lift I have been having drive line vibes like mad. When you let your foot off the gas it feels and sounds like the drive shaft is about to pop out of the x-fer case. Guys at RC told me that one is not needed, but the local shops said that they would really consider one as it is sitting out quite far. Suspension has sagged about 3/4" over the past week, but really has not improved. It has an inch x-fer case drop on it right now, but don't really want to start dropping it further by stacking up washers.

Please advise.

 

I have a 5 " lift and a 1" t-case drop and no vibes whatsoever, so i would look into having your driveshaft balanced or possibly your tires (if you put new ones on after the lift which i suspect you probably did)

 

X2. Check your tires. With a 3" lift and a 1" TC drop, you shouldn't have ANY problems at all.

 

That is good to note you can get a larger lift and not need a SYE. The vibration existed with both the 235 and 31 that are on there now. So thankfully I can eliminate that from possible causes. End lift was about 6" taller than it was so we are a little out of the original spec for the 3" lift.

 

Not all cases are the same though. If you're saying your "3 inch" lift actually gave you 6" of lift, then you will definitely need an SYE.

 

what year is your xfer case and jeep? what rear axle do you have?

I had bad vibes at 3 inchs with a 1 inch as well. a SYE isn't a bad decision if you want to get bigger in the future. you can always try leaf shims too, because you're jeep should hold a 3 inch no problem

 

Be sure you have shims. It might be coming from the end of the drive line to the front of your rear diff. shims will even that out. Id get 3 degrees

 

Good point OEM shims were rot and were not reused. Now the vehicle has zero shims installed. Might be part of the root cause.

 

got pics of angle

 

I have that same exact problem, im running 3.5", 31's, and i also have a 1in transfer case drop......Whenever I let off the gas its almost like a bad grinding and when i put my foot back on it feels like something is almost re-engaging again... Its weird, i almost think it may be slop because my slip yoke does not seem all too bad....Im having a jeep specialty shop look at it in two weeks

 

Hey have you been driving my Jeep? Sound way to familiar...

Regardless. I just got back from work and snapped a few photos. As for the driveshaft angle it is sitting at 17.5 degrees off horizontal using ground as my reference point. Used an old Hilger & Watts M.C. Clinometer measuring the angle so it is accurate. Not sure how to accurately read the yoke coming out of the transfer case or diff. The base of the clinometer is fairly large getting in tight spaces.

 

My buddy had a new lift put on his dodge, and it was doing the same thing. After lots of money swapping parts, it turned out the front shocks were just loose, so when he let of the gas, or braked it would shake like hell. If you can't find anything else it might be worth looking at.

 

the angles are not the problem

 

what is sitting out quite far the slide yoke on transfer case

 

i think i found the problem see hoe far you drive shaft has pushed the rubber boot in to the transfer case try taking tc drop out 3 inch lift is not that much maybe drive shaft is now to lonb