No, syes are for the rear of the t-case, not front like he implied. Chances are you will still need one.

Ok, thanks

You have a 2000 model year XJ that was built in late 1999. You will notice that it's got coil packs instead of a distributor, mini-catd in the exhaust manifold, and a low-pinion front axle.

Use of an SYE is actually relevant in the case of the LP front axle. When you install a transfer case drop, the goal is to correct the driveline angle on the rear prop shaft to make up for the stock single-cardan shaft and TC-side slip yoke. Generally you get it down about 1" with spacers. You have to realize though that the engine, transmission, and transfer case are bolted together. When you put in a TC drop the whole assembly pivots on the rubber mounts. Aside from tilting your engine and causing the mounts to wear faster, the front of the TC is now actually pointing *UP* at an angle opposite to the rear. The Low Pinion D30 in the 2000 and 2001 already has a less than ideal angle, and its just been screwed up lol. Some people actually get vibes from the front as the double-cardan shaft binds due to the extreme angle. If you put an SYE on the rear you run a double-cardan in the back too, so you remove the TC drop and restore a good angle for the front shaft.

Thanks Salad, Im pretty ignerant when it comes to some of the wording. I appoligize. I see that you have a 1999/2000 XJ too. We have 175.000 miles on ours and it has been a great vehical. Im just now hearing about this casting flaw in the 2000s and it appears that I have that motor. If my motor ever fails, can I replace it with a 98 or 99 with the better block? I dont want to spend a bunch of cash on a lift for the jeep if its not reliable.
Thanks
Ross

OK. I have a 98 and I have this lift installed.

A few observations -

The likelihood you will need a SYE is very high, as is the case with most 97 and higher XJs. If you have a 242, there will be less choices for hack-n-tap.

If you do need a SYE, you might also need a rear drive shaft. Keep this in mind. You will also likely need shims to adjust the axle angle.

The RE 3.5" lift is notoriously higher than advertised. Mine is still at 4.5" after several months. I have 32s installed, kept the factory flares and no rubbing at all. RE Used the same springs for the 3.5" and 4.5" kits, which might explain the issue...

The RE shocks are re-badged Bisltein 5100s and absolutely great. If you can get a packages deal, go for it.

I have added an RE adjustable track bar, RE tie rod and a drop pitman arm. I think it is the minimum necessary to improve steering.

Since I found the ride a bit rough in front, I also relocated my control arms lower and used adjustable arms - not absolutely necessary, but I like it better...

Lift it first and then see if you even have vibes after the lift. Tcase drop is only a band aid fix, so get the sye if you can afford it. But at three inches you may not even have a need for either one!

On my 99 XJ I installed the same 3.5" re lift with an re trackbar and 5100 bilstien shocks and 4* shims and I have 0 driveline vibes and works great love the ride quality

Every Jeep reacts differently to certain mods.

Funny, my name is Ross too! However I have a 99 XJ that was built in the summer of 98. If the head cracks all you need is to replace the head, unless you drive around for a few weeks ignoring the mysterious coolant loss (which means rebuild time). If for some reason the whole block needs to go, I believe the compatible years are 97-01 XJ blocks. It's just the head that changed. Note that the TJ and WJ blocks aren't really compatible in that the mounts and accessory brackets go on differently.

Plenty of people live with 0331 heads just fine - you just have to be super vigilant about cooling system maintenance and make sure it never overheats