Strange Lift Problem

[ezbuzzsaw]

I have done many lists on XJ's and TJ's, but this is a first, we put a 2" budget boost in a friend's XJ last week end Blocks in rear and a set of my old used RE 3" springs in front. All went well easy lift done in under 2 hours. So he comes over this morning and says when he engages 4WD it locks up??? So I went for a low speed drive with him and sure enough that is what it does. Says it never did it before, so I am sure it is the linkage and all looks good there. This time I have him drive and I get out and watch. He starts rolling forwards and the passenger rear tire locks up for 6" every 3 to 4 feet. When I take it out of 4WD it wont come out of 4WH so I put it in reverse and it pops out and is fine in 2WD. So what can make the rear only lock up while in 4WH???? Please give me your thoughts about this...
Thanks!:confused:

[4.3LXJ]

Since it is not your rig, start from scratch on this one. It sounds like he has different gear ratios in the axels. You can check that by jacking one corner up and rotating the drive shaft exactly one turn and then counting the wheel rotations and dividing by two for the ratio. However, the point is the wheel rotations should match exactly front and rear. If not, he has different ratios. Does he have a 5 speed or auto tranny?

[ezbuzzsaw]

Since it is not your rig, start from scratch on this one. It sounds like he has different gear ratios in the axels. You can check that by jacking one corner up and rotating the drive shaft exactly one turn and then counting the wheel rotations and dividing by two for the ratio. However, the point is the wheel rotations should match exactly front and rear. If not, he has different ratios. Does he have a 5 speed or auto tranny?

Two things, it is an auto and it worked great before the simple two inch rear lift??? It actually locks up the rear tire but only for a second and only in 4:bang:WD??

[4.3LXJ]

I understand what you are saying. But I would check it anyway. Doesn't cost anything. I have had this same thing happen to me on a Toyota. It had 4.11 in the front and 4.27 in the rear. If the rear axle has been replaced, it is a possibility.