SYE and driveshaft hunt

I've finally broken down, and got my SYE. The vibes won.
From my initial measurements I need a running length of 34" and want to use a junkyard shaft. From the tables I've found, I see some ZJs have ones that are 33" and 33.5". Would these work? For some reason this is giving me a headache.
2000 XJ, AW4, 231, and 8.25 diff, 2.5" total lift

Hack and Tap or Advance Adapter type full SYE ?

What and how are you measuring ? Measure the extend and compressed length of the main shaft, center of u-joint, to center of u-joint. Stock XJ is about 28" compressed and 31" extended.

I have a stock XJ front shaft on my AW4, 231, and 8.25 diff, 5.5" total lift. I used the same shaft at 3.5" total lift.

My SYE stock front driveshaft is at 30" now (center of u-joint to center of u-joint), and a little passed the center of the splined yoke travel. I don't see how you would need a longer driveshaft.

CarbonXJ said:

I've finally broken down, and got my SYE. The vibes won.
From my initial measurements I need a running length of 34" and want to use a junkyard shaft. From the tables I've found, I see some ZJs have ones that are 33" and 33.5". Would these work? For some reason this is giving me a headache.
2000 XJ, AW4, 231, and 8.25 diff, 2.5" total lift

Click to expand...

Are you including the double cardan in that 34"?

Tim_MN said:

Hack and Tap or Advance Adapter type full SYE ?

What and how are you measuring ?

Click to expand...

Rugged Ridge full SYE
I measure from the center of the rear diff yoke to center of the yoke on the transfer case.

bcmaxx said:

Are you including the double cardan in that 34"?

Click to expand...

I am including it.


I'll try and take pic as i measure again.

You missed a good sale. Amazon had the Rugged Ridge SYE for $129.67. I am not ready for one yet but I had to lay it down for that price.

OK, some visuals.
From here:



to here:

From there, to there, as pictured with a HD SYE, is about 34". Extended to 34" a stock XJ front driveshaft shows 2" of slip exposed and 1" of extension remaining. At most, the driveshaft extends/compresses about 1/2" to 3/4" either direction

Use the Google if you don't believe me, most AW4, 231, and 8.25 diff HD SYE use a stock front driveshaft with no issues.

I used a frt shaft from a 4WD Dodge Dakota. It fell half way between the length of a ZJ frt shaft, and an XJ frt shaft. Just throwing that in there, in case You need that option.

You're needing the SYE with only 2.5" of lift? Yowza.

Well, I suppose I can see it. I've got a 2000 with 2.5" (RE AAL), but I've got the 242, and I occassionally feel what could be the start of some baby vibes(?) when I'm really punching it on an onramp or something.

Been wanting to go about an inch taller but have been afraid to get into exactly what you're going through right now. Seems WAY too confusing for a newb like me!

Hopefully, you'll get it all figured out here in nice, clear, easy-to-follow steps and then I won't have to think about it at all when I do it! Like you, I'm pretty sure I can wrap my head around the SYE itself, but when you start getting to the proper length for the driveshaft . . . I just freak myself out. Think about it too much or something. Make it more complicated than it needs to be. Something like that.

Anyway, good luck man!

Tim_MN said:

From there, to there, as pictured with a HD SYE, is about 34". Extended to 34" a stock XJ front driveshaft shows 2" of slip exposed and 1" of extension remaining. At most, the driveshaft extends/compresses about 1/2" to 3/4" either direction

Use the Google if you don't believe me, most AW4, 231, and 8.25 diff HD SYE use a stock front driveshaft with no issues.

Click to expand...

That's what i was concerned with. Would that be enough to use a front XJ shaft? I also don't wont one too long and jam my transfer case either. For some reason I just can't wrap my head around this...

jamiemac said:

I used a frt shaft from a 4WD Dodge Dakota. It fell half way between the length of a ZJ frt shaft, and an XJ frt shaft. Just throwing that in there, in case You need that option.

Click to expand...

That's good to know too.

Teephphah said:

You're needing the SYE with only 2.5" of lift? Yowza.

Click to expand...

Yep - vibes on accel, at 40, 60, and 70, and thunk on decel and suspension unload. got worse over the last year - all on 2.5"
But I do have a shackle issue in the rear (I think it's shackle) but that's getting replaced when I go a little higher.