i have a 96 ram 5.9 4 wheel drive i have posi lock setup instead of the cad setup..when i shift to 4 wheel drive and drive the 4 wheel drive shifter vibrates and shakes it does not do it in 2 wheel drive so i am assuming this is bad what could be causing this?

 

A little vibration is normal, but you need to check the front drive shaft, ujoints at the axles, hub bearings,pinion and the fluids in the diff and transfer case.

 

ok how do you check a u joint? for little vibration should i b able to see that it is shaking more than in 2 wheel drive?

 

Well yes! Because now you are putting tension on those parts that is not there when it's in 2 wheel drive. And you can check the joints by putting it in 4 wheel and make sure it is engaged, raise the front end and rotate the wheels forwards and backwards and look at the joints and see if they have any play.

 

for testing play in the drive train, park it level, in neutral, and make sure there is no tension on any parts. for u-joints try to get a couple of large pliers on the u-joint yokes or cap bolts and wiggle in opposite directions. there should be no play and no movement at all. the front drive shaft has a double cardan thing with the ball in the middle. test all those parts for play. also test front diff pinion/yoke for play there.

if nothing there, its more than likely something in the t-case. broken snap rings are common. obviously... don't drive it in 4wd with it shaking and vibrating. download the merry christmas 01 service manual for diagrams and info.