what are the pros and cons for both? and for someone who is on a tight budget like me, which option is best? i will be installing a RC 4.5" full packs kit along with a .75" BB spacer kit..

 

you cant beat a sye with a new driveshaft. and thats the last time you will have to modify or even mess with that problem we all run into when lifting our xjs

 

iron rock offroad has a $200 kit that includes a driveshaft. save up and then dont wory about it and have a smooth and reliable drivetrain. like it was meant to be. i am in the proccess of saving up for one now

 

with a lift of about 5" i dont think you can get away without an SYE.....they give you a longer driveshaft that can use a double cardan/CV joint...Iron Rock Offroad sells Hack-n-Taps with driveshafts for pretty cheap

http://www.ironrockoffroad.com/Merch..._Code=IR-X_HNT

the degree shims are probably not enough for that amount of lift....you may get away with it in conjunction with a t-case drop tho

 

Isn't the OP asking which is better, SYE vs shims?

I don't think the SYE would eliminate the need for a set of shims. The SYE won't get rid of the nasty pinion angle in comparison with the t case, will it?

Wouldn't the better question be shims vs tcase drop?

In which case I've heard shims are the "correct" way to go.

 

thanks for the advise so far guys. wen i install my lift i was going to do the shim option and just get it over with, but im real **** when it comes driveline vibes and i dont want any of them when i install this lift. so i guess im just going to have to save up and buy the H&T, even though this will delay my install day but it will be worth it, even though i want to install it before it snows again this year. (Live in MD)

 

Pinion angle is not the real problem, it is the drive shaft angle that causes the vibration. The SYE lengthens the drive shaft enough to correct the angle enough to stop the vibration caused by a binding ujoint.

 

sye is meant to be used in conjunction with shims.

not one or the other.

 

What?

How does getting a longer driveshaft solve the angle issue and the binding?

If you drop that axle via a lift, its not going to line up with the tcase any longer, like it should. Thats what causes the vibration you are talking about. If you correct the pinion angle, it'll solve the issue.

Thats why people drop the tcase as well. It eases up those angles, because you lower the tcase as you lower the axles via lift.

 

It solves it because the tail housing in the sye kit is much shorter than that of the factory slip yoke, making the distance between the diff and the tcase greater. more distance and longer driveshaft makes less of an angle.

 

Think about that.

The driveshaft has nothing to do with how far apart the diff and tcase are. Its the size of lift on the truck that pushes the diff away from the tcase. The longer driveshaft just makes up for the distance, it doesn't change the angle the pinion points at. That'd be the job of the tcase drop or shims. You need the pinion to point more at the tcase.

 

I totally see where you're coming from, however what I am saying is that the sye kit I got at least, makes my transfer case a lot shorter making the distance greater between the transfer case and the axle, which brought my pinion angle back to normal. I had horrible vibrations before installing that. Do you see what I mean?

 

I made a quick drawing on MS Paint to show what I was talking about. The shorter tail housing on the sye kit makes for less of an angle, eliminating vibration.

 

There are other drawings on this forum that show the same thing.

You don't shorten the tcase whatsoever, I have no idea where you got that idea. Its the driveshaft length that is changed. The SYE kit eliminates the sliding shaft.

You'll still need shims to do this correctly.

 

this is correct