4x4 knocking

1995 jeep xj
np231
3" skyjacker lift with 31's
problem started 1 year after lift install

My xj started giving me some vibes a while back. At first it was just at VERY low speeds (10km/h range). It DID run fine on the hwy. Now it has developed a high speed vibe at around 100km/h.
I had my axle u joints done this summer so Im thinking my drive shaft u jointsight be shot.
I went to pull my boat out of the water in 4wd and I got a very bad knocking/binding noise.
Now, the truck shifts fine into and out of 4lo, 4hi ect but if I accelerate or brake or turn in any 4x4 I get the banging noise. The truck shakes a little as well.
Does this sound like driveshaft u joints or something else?

you shouldn't use a 231 in 4wd on the street anyways.

Thanks for that advice... but I never said I was on the road.

Sounds like the t-case chain is binding. Meaning too much slack.

could be your front ds u-joints. almost sounds like axle joints. park on flat ground and put the tranny/ x-fer case in neutral. crawl under there and muckle on to your driveshafts, see if there is any play. check them side to side, up and down as well as rotationally. if there is any play in the shaft, the joints are shot. sounds like it should be obvious if its making that much noise. also, check the retaining clips on your axle joints, once and a while, mine will loosen up and the center caps will try and sneek out. just 'cause they were replaced somewhat recently doesn't nessacerily rule them out unfortunately.

lancey3 said:

you shouldn't use a 231 in 4wd on the street anyways.

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shouldnt be a big deal pulling a boat off the ramp. usually the ramp is going to be wet anywas, as long as he is not trying to turn on dry pavement he should be ok.