I currently have a 2" space in the front of my jeep, in the next couple weeks I plan on getting a 4.5" rough county lift for it all the way around. I am debating on leaving the spacer up front, but I've heard some people say thay anything over 4.5"-5" I need a new longer drive shaft due to its length and vibrations that it will cause. Is there some accuracy to this?

 

You will need a SYE and a new rear drive shaft. You can get a Hack and Tap and a refurbished driveshaft from ironrockoffroad for 199$.

Most people just put the front driveshaft from a junkyard cherokee in the rear.

 

So if I take out the spacer and have 4.5" all the way around, do I need the sye and rear drive shaft or should I just get them anyways and should I drop the t case any?

 

at 4.5in you will need to do a SYE/New Shaft OR T case drop.. although I don't understand the point of lifting a Jeep then lowering it via the T case drop..

 

Ok cool that's good to know! Thank you much for the info...

 

So what does the SYE do anyways for the front driveshaft

 

Nothing

 

Hmm...what's the purpose? Just to extend the driveshaft?

 

SYE is for the rear driveshaft. You already have an "SYE" and a double cardan driveshaft up front from the factory. You dont need to do anything with the front as far as driveshaft, but if you leave the spacer in to be at 6.5 with short arms up front your angles will be way off and you will have all kinds of other problems.

 

I actually installed one last night...

On the back of your transfer case there is one output shaft. It is splined and the end on your stock rear ds is as well. How it
Works stock is that if you hit a bump or flex it, the actual driveshaft slides on the out put shaft.



you see the rubber boot in the picture? That's where it slides to accommodate for the rear axle going up and down.

When you lift you jeep you change the angle of the driveshaft and that slip yoke starts to cause vibrations.

The solution:

An SYE and double cardan driveshaft




And to go the cheap route, you can get a hack N tap from IRO with a driveshaft for $200 (they refurbish stock front drive shafts from xj's, new u joints, paint)

Or you can skip their driveshafts for $80 and pull one from the junk yard (mine was $16.67) and bolt it in!

This is how the back of mine looks as of last night




And it got rid of my driveline vibes at 57-62 mph

Hope this helped ms good luck!

 

Check out my post...

Answered all my questions...

https://www.cherokeeforum.com/f67/rc...ut-sye-125740/

 

Ok cool I think I got it for the most part...so basically the best route to go would be just to get a SYE and driveshaft from IRO and not have to worry about stuff falling apart later on...its my daily and I drive 40 miles to work and back everyday so I need it to be dependable. Thanks for the info guys!

 

Just to verify, the hack n tap from IRO is basically bolt on, and I don't have to open the transfer case at all to install anything. I did some more looking around and I saw someone did the sye for the rear and opened up the t-case. I'm not too comfortable with that right now lol

 

installing a real SYE for me is easier then a hack in tap. HT you have to cut and make sure you are drilling dead center. I have have seen/had 2 taps break on me. 30min opening up the case and some snap ring pliers and you are done with a REAL SYE. so many write ups on how to do a REAL SYE that there truly is nothing to be worried about.

 

It's a cost factor for most people like myself...