99 XJ 4.0 AW4
4.5 RC X-Series

I installed the IRO HnT SYE a few months back and used a stock front drive shaft to replace my stock rear drive shaft. I have noticed recently that my driveshaft APPEARS to always be fully collapsed.

Will this cause me any problems? Is there an ideal amount of extension that my DS should have? What are the risks here?

Thanks!

its too long, it should be at about the center of its travel. just remove it & take a measurement from yoke to yoke, then have a driveshaft shop shorten it, they will know how long to make it by the measurement you give them. if its a jy / old used ds i would have them rebuild it. then you know what you got. you could damage the tc w/ it too long.

Did you actually measure the length when you cut the part off the T case, or just guessed and cut? Me and my buddy both have front drive shafts in the rear, with IRO hack and tap and had to both cut way different amounts off.

Wow, I definitely don't want to damage the TC because of this. When I put it in, I didn't have to force it in, but it just barely fit. I will post up some pics tonight.

@Brandonrcm: Yes, I measured (twice at least) the amount that I cut off the output shaft, and did exactly what the directions from IRO said. It's a 29 spline, so I figured they would have it down... Apparently not.

Here's whay I'm working with... What do you guys think?

If there is still some of the output shaft left , go ahead and cut about 3/4in more off of it. I had to cut more then iro instructions. If not you could cut some of the back of the actual yoke to be able to cut more of the shaft off. Take a pic of your output shaft and yoke if you can.

Alright, here's a photo of my t-case... Plenty of room to take more off of the output shaft but then I'll need to re-drill and re-tap the hole. Not sure I have enough there to do that and cut the entire currently drilled hole off. Thoughts?

Yep. You should have put the yoke on and tried the driveshaft for lenght first. Thats exactly what hapenned to me. I cut some of the back of the yoke to be able to cut the output shaft down an extra about 3/4 in. But luckily I noticed there would be a problem before I did all the work. Not a big deal. Or you could check a junkyard for a shorter driveshaft. Not all xj driveshafts are the same lenght. Thats why this happens.

before you cut that output & yoke off too short find out what the minimum recommended spline engagement lenght is. i think its 1 1/2 " ? maybe, ask who supplied the kit.

ps. it maybe easier to have the ds cut down a little shorter & rebalanced.

Instructions say 1.25 of spline should be left on shaft.

Oh yeah. That goes without saying. The instructions say you could vary the cut by 3/4in in either direction as long as the splines are long enough. Mine were so I cut it shorter. The problem was my yoke was to long to sit flush on the shaft then. So I had to cut that a bit too. I think they designed it like this on purpose to be able to make adjustments depending on how long your driveshaft is. But the instructions could be a bit clearer IMO.

I foresee a problem with cutting the shaft shorter, redrilling and retapping the hole because I think that doing that without ruining the existing threads will be near impossible. Am I off base on this one?

Everyone is right though... Looks like I should have cut it shorter to begin with. Lesson learned!

Is there a spec for maximum spline engagement on the DS? (Couldn't think of a better way to phrase that)... Basically the minimum gap between the 2 pieces.

i have the same h & tap on mine, i had my old rear ds retubed & rebuilt to fit properly between the yokes . they left me 1" for in travel , which leaves about 2 1/2 " out travel. which is just right, you need more travel out for droop then needed for compression. looks like you need to shorten the ds by 1 " , its a simple job for a shop, cut, reweld spline shaft back in & balance. under $100 i would think.

i would cut the output shaft shorter, it would help with the drive shaft angle.