[JEEP3312]

just asking if I put a 4 in. lift will I need to make the drive shaft longer, if so how hi can I go befor I have to make it longer, New to the jeep life with a yj ,cj was 3in.

[1997_Sport]

it depends on the jeep. I have a 4in lift and i dont need a SYE but somepeople have a 3in lift and need one. so it all depends on the jeep.

[her94yj]

depends each jeep and lift is differnt. some just need a t-case drop kit some need a sye

[burnout88]

The YJ has a really short rear driveshaft. And once you lift it the angle can be very extreme. Generally, my real of thumb is if the lift is 4 inch and up you will need an SYE (slip yoke eliminator) kit installed in the transfer case. If under 4 inch's you can try it without but if you get vibration you will need it. So on a 4 inch lift I would plan for an SYE kit in your budget. These links have some pics of what I am talking about. SYE kits run between $200 to $300 and are not to hard to install. Basically they allow addiitional lenght in the driveshaft by shortening the connection at the transfer case. I am not a fan of the T-case drop. The proper way to due it in my opinion is an SYE kit.

http://www.cardomain.com/ride/2536636/2

http://www.rockcrawler.com/techreports/reyjextreme/page3.htm

[1998zj]

My 95 with the 2.5 engine needed a Slip yoke eliminator bad. It sounded like a bunch of marbles in a coffee can when I would let off of the gas. It kind of depends on which lift you get too. My RE lift gives more lift than some of the others out there.

[Leans93]

I ran a 4" lift and 3/4" lift shackles for a total of 4 3/4" lift. I used 2.5 degree shims and a 1" transfer case drop with the stock drive shaft and no vibration issues at all.

A transfer case drop will reduce ground clearance. Also I agree that each Jeep and lift is different so you really won't know until you lift yours.

I am now running no transfer case drop with a SYE and CV shaft with 8 degree shims. Also no vibration issues at all.

[DriveTooMuch]

Am I the only one who is struggling with, "each jeep is different"? I think each yj jeep is fundamentally the same but with different options such as 4 or 6 cylinder, standard or automatic, etc. I don't mean to pick at what you are saying but I would think each yj jeep is basically the same dimensionally but with different options. Is there something I am missing here and why they are so drastically different from each other as I am perceiving it?

[Joe Dillard]

You can have two identically equipped YJ's with the same motor, tranny, tires, lift, AC or no AC etc, then install the same exact lift kit & maybe neither will have rear driveline vibes, or one will & one won't, or both get them.

It's a gamble as to whether or not a lift will cause driveline vibes - but in general, the taller you go, the more likely you are at having them. Even a relatively short lift (2" to 3") will sometimes give you vibes.

My old SUA 4" lift with 5/8" booms never gave me vibes, but I did a have a 1" tcase drop & rear shims.

[burnout88]

Originally Posted by DriveTooMuch

Am I the only one who is struggling with, "each jeep is different"? I think each yj jeep is fundamentally the same but with different options such as 4 or 6 cylinder, standard or automatic, etc. I don't mean to pick at what you are saying but I would think each yj jeep is basically the same dimensionally but with different options. Is there something I am missing here and why they are so drastically different from each other as I am perceiving it?

All vehicles are built within a "range of torlence's" considered acceptable. Not exactly same, but close to the same. On modern cars robots and computerized process control has greatly reduced these torlences and the cars are more close to being "exactly the same".

However, on a 15 year old Jeep built on a 23 year old platform, and with a process that was designed pre-computor area you can have some significant differences from vehicle to vehicle. Most Jeeps from our time where literally close to being hand built on a production line. Throw that in with 15 years of wear and tear from wheeling and different driving conditions and the slight production differences in all of the aftermaket parts installed over the years and you can have two Jeeps with very different torlences.

Did I also mention that Jeeps have never really been built with BMW precision.

[JEEP3312]

HEY !!!! Thanks for the info sounds good,,,,,..4 in with a SYE will will be a nice set up

[dos0711]

I have a SYE for a few reasons....

No loss of ground clearance.

Eliminated vibrations

and finally, I can drive home on the front axle if something happens to the rear driveshaft. Can't do that in a stock setup.