Tom95YJ

Here's my setup 99 XJ 4.0 aw4 231 no sye. 8.25 3.5" lift locked rear I've never had any vibrations with this until tonight. I was in the merge lane getting upto speed (wot) to get on the hiway my wife accidentally bumped the shifter into Neutral white getting getting a large cup out of the cup holder. The engine went to the red line and I let off and threw it into gear before the Rpm dropped to a save level we heard a bang in the rear driveline. Then started getting a vibration. So I we pulled over I checked it out all the joints feel good. Trans mount is good ,engine mounts are good linkages are not bent goes in and out of 2wd 4hi N 4lo fine. No bent leafs . But soon as you go above 20 the vibration transmits into the steering wheel. Like tire balance is off. Anyone have any ideas of what it could be ? No it's not death wobble either I know the difference Normally I'd say hell with it and drive my YJ but that is not an option since its broke down in my garage waiting on parts

98XJ40K

Do you only get the vibes when it is in a certain gear? Only thing I can think of would be that you possibly chewed up some teeth inside the trans and it vibrates when in that gear... just spit balling here.

Tom95YJ

I won't go above 20 cause I want to keep the rpm low incase something does let go it can stop quick. So I've only had it in 1st and 2nd and it shifts smooth as always The steering wheel will shimmy left to right about 1" Its not making any noises out of the normal either. I'm wondering if the output shaft on the tcase is bent or center ball on the front shaft may be bound up

98XJ40K

The output shaft is something I didn't think of. I would have guessed u joints but those were good.

Tom95YJ

If the output is bad my neighbor may have a spare. Iirc he has a stock rear shaft also

XJwonders

Pull out a gun on the xj. Maybe it ll learn to respect you and stop vibrating.

Tom95YJ

Or I could put the winch on my YJ and sell the damn thing and but a Towrig

Larry's XJ

More noggin pokin needed.

Front shaft shouldn't been affected by neutral slam. Pull rear shaft inspect splines on TC and slip yoke, joints rotate smooth?

Tom95YJ

I just pulled the shaft joints and yokes are fine. I bent the output shaft. So it's staying parked until I get funds for a sye. And shaft so I'll be pulling the front axleshaft and throwing them in my YJ so I can limp it around until I get a new rear yoke for it

XJwonders

I got a spare tail shaft (OEM) if u want. Free but u pay for shipping. Let me know

Tom95YJ

I'm pretty sure my neighbor still has his stock output from his Xj

XJwonders

alright just let me know