Does Anybody Know...?

Does anybody know what the distance is (or should be) between the rear driveshaft upper yoke and the back of the t-case? Either on a stock XJ or a lifted XJ with a SYE and proper length drive shaft. Also, how far will the slip yoke slide out before it falls out?

That dimension will be different depending on the axle and transfer case combination. For example, the Dana 44 and the Mopar 8.25 axles are both longer than the Dana 35, resulting in a correspondingly shorter driveshaft. There is no one, single "magic" number.

What is it you're trying to figure out?

'94, 4.0, AW-4, NP-231, D-30, D-44 (swapped in from oem C-8.25), 8" lift, 35's. The deal is, I'm at 8" of lift with NO SYE, (I know, I know, lock him up, he's crazy!) but I don't have any vibes, none, zero, ziltch, and I'm trying to justify to myself why I should get a SYE if I don't have any vibes. The main thing I'm concerned about, is at such a high lift, at full droop, that the slip yoke might pull completely out. But i've had the thing on jackstands completely in the air, and it's never come out. So, if the only reason to get a SYE is for vibes, and I don't have vibes, and my only concern is the yoke slipping out, then couldn't I just get a longer driveshaft or a YJ yoke?

Cujo said:

...So, if the only reason to get a SYE is for vibes,...[/B]

Click to expand...

NOT the only reason.

The extreme angle at the front U-joint (slip yoke) is putting an extreme amount of downward force on the rear bearing of the TC output shaft.
If you've been running this setup for long, I'll bet your bearing is going to let go soon.

Install an SYE while you still have a servicable TC case.