i didnt think it was funny the first time, must be a white trash thing.

 

newer xj's don't have the 3 or 4" of extra housing were your slip yoke slides in and out. they just got a rubber boot. so the first ujoint is like 8" or so back from the t-case, unsupported so very vibration prone. the tcase lowering kit i used to run measured like 1.5" i think, made the tcase look very vunerable.

 

couldnt you just get your drive shafts extended and not drop the transfer case at all? and what is a SYE?

 

you still would have to shorten main shaft out of the tcase some how to make room for the longer driveshaft. SYE, slip yoke eliminator, puts a fixed yoke on the back of the tcase like the front shaft output has. then you'll need your longer shaft.

 

There are two different types of SYE kits. one is known as "hack 'n tap" and the other is just a regular SYE. the hack 'n tap uses the stock main shaft for the transfer case and you just shorten it down, drill and tap it for the fixed output. The other type comes with a new mainshaft and everything you need for SYE. Both types require a new driveshaft...the recommended way to go is a double cardan/slip yoke type shaft like that on the front output of the transfer case. Putting in a longer driveshaft without an SYE kit is a waste of money because you're still stuck with the stock slip yoke set-up.

 

i agree with you, a longer shaft w/a slip yoke would be a waste of time and resources. hack'n'taps are less expensive than SYE's , but i would recommend a SYE w/a new mainshaft not a modified stock. thats wat i did, the new mainshaft is way beefier.

 

It is not so much the LENGTH of the driveshaft but more the ANGLE that the shaft spins.

Stock XJ d/s angle very low, U-joints have the least amount of bind in them and rotate smoothly.

Lifted XJ d/s angle steeper (higher lift=steeper angle) U-joints have more of a tendency to bind, thusly causing drivetrain vibrations.
Extended periods of time with these vibrations and associated u-joint bind can drastically shorten the life of drivetrain components.
And as luck will/would have it, they will leave this world when you need them the most or when you are far from any help.

EVERY XJ IS DIFFERENT.
Some components will wear at different rates due to driving habits, upkeep, and overall quality of the parts and installation.
Just because the Xj in your possession did not require a SYE does not mean ALL XJ's do not require it.
Yours doesn't need it--->Consider yourself LUCKY...PERIOD

Lets not forget there are added BONUSES when a SYE is installed.

Your TC is now SEALED.
If for some reason a U-joint does let go... Simple d/s removal is all that required to "limp" home in 4hi with NO FLUID LOSS.
Pull out your slip-yoke driveshaft and see how far you can make it when fluid starts to pour out.

Driveshaft usage: Certain SYE designs will allow you to utilize a "front-style" driveshaft. You only have to tote around ONE replacement part.

SYE
Overkill -or- Good idea?

 

ok,,yall are scarin me here..i put in a 3" lift about 6 months ago and havent had any vibrations. but now ya got me thinking i NEED to drop the case a lil..hmm..

 

Absolutely right, but a longer DS = lower angles....so thats another bonus to having a SYE is that your driveshaft is now operating at much much lower u-joint angles due to a double cardan on the case end and the pinion being pointed at the case...a set-up like that will have its u-joints last more than double the amount of time that a standard slip-yoke will chew through u-joints

 

your 90 xj has more support for the slip yoke, 97 n up 231's have a shorter or actually no housing for the the slip to slide in. justa rubber boot to seal the exposed splines. if happen to see a newer xj some where take a peek underneath.

 

cool, now i feel better 'whew'..

 

I have a 3in. lift on mine and I get a grinding noise when i use the brake too heavy. Also once I hit a large pot hole and my drive shaft popped out. Will a tc drop and shims or angled lift blocks help or do I have to get my drive shaft lengthened?