SYE Question

Alright i have a 3 inch lift and i was thinking about getting new shackles and bb for the front. would i need an sye?

what year? axles? how big of a BB? Do you have a tranfercase drop or shims now?

lift it, if you get vibes, then sye
Scott

always budget for an s.y.e over 3 inches.

1.5 inch BB and i have a transfer case drop

I've run 6" for 2 years, no slip yoke kit. Every Jeep's different. Like ttocsnekia said, lift it, see if you get vibes. I'll probably go to a slip yoke kit soon, but just cuz I want a better driveshaft out back, from Tom Woods of course.

I just finished doing the SYE to my 91 with the RE 3.5. Mostly, I did it for piece of mind, but all of my vibes are gone except my exhaust rattle.

I did the RE 3.5 lift and really did not need the SYE kit but did it anyway so as not to worry about it. Never had vibes w/o kit but just wanted to do it.

This is kind of a confusion issue. I have heard from some people that just drop the transfer case an inch and shim the rear to match. usually 2.5 or 4 degress depending on the lift.. and that a sye is only for rock crawling and you wont need it unelss you go over 4.5".

I have a 96 xj with a RE 3.5 superflex I had installed a few days ago. BY the way it brought up my jeep about 5+"(not yet settled). Then check my pinon bearing and ujoints (these can cause the vibrations too) after that i guess i would have to get the SYE.. but i still cannot see how having a sye would do anything to help with vibrations. maybe one of you guys knows better...???

A SYE helps by allowing you to run a CV style rear DS and that would allow for more difference in angles between the TC output and the rear axle pinion.

The reason that not all XJ's are the same depends on rear DS length for the most part.

A manual trans is shorter than a auto trans. A NP231 is shorter than a NP242. The older TC output slip yoke is marginally shorter than the sealed units. The pinion on a D44, D35, and 8.25 are all slightly different lengths. The longer the DS the less prone to vibes. A manual trans NP231 with a D35 will have a longer DS than a newer model with a auto trans Np242 and a 8.25.

The SYE CV combo will allow the DS to turn vibe free. If you do a TC drop, you are adjusting the angle on the output shaft, but at the same time increasing the angles on the front. If you do a TC drop and feel no vibes....except at higher speeds, then there are more than likely vibes and you just don't feel them at low speeds.

Another advangtage on the older models is that if you are out wheeling and the rear DS take s a hit and cannot be put back on, the slip yoke won't stay in the TC and the fluid will run out of the TC.

lancey3 said:

Alright i have a 3 inch lift and i was thinking about getting new shackles and bb for the front. would i need an sye?

Click to expand...

Maybe.

if you decide to install a sye or not... it does not change that you still needto have your agles of the tc and rear end match... so sye or no...

i would think you would still get power loss and so vibs if you dong drop the tc and/or shim the rear

my tc is dropped so yeah, but i just wanna know if the bb + my 3 inches already would need an sye