I recently installed a SYE in my 2000 xj, and got a front driveshaft for the new rear shaft and am wondering if it is an acceptable length in terms of slip.

Fully extended the shaft has about 3 3/4" of slip travel and in my jeep it has about 1 1/4" of travel out and 2 1/2" inward.

Will this be ok to run or do i need to get it lengthened a small amount?

 

2 things:
You should be OK. The slip joint moves suprisingly little when the axle moves up and down. My front shaft covers only about 3/4" of slip in the axle's entire range - which should be a lot more than a rear. One peace of mind thing you can do is jack up the rear end by the bumper/tow package/something that can handle it besides the axle and let the axle hang by the springs. Then see how much slip you used. On the road, it may move a little more than this test, but not much.

Secondly, if you needed to lengthen it, you might as well get a different shaft. To lengthen a shaft, it usually will need to be retubed. This tends to be more cost that a junkyard driveshaft is worth.

Good luck

PS...that's what she said to several parts of my post...HA