89cherokeelimited

Take out your front driveshaft and see if you have vibes. If you do then you have a little more room to know where to start. If you still have vibes with your front shaft out then you know start in the back

BigJeepBigSnow

I just talked to my shop guy.. he said he checked the joints and they are fine without any play in them whatsoever. He also said the slip yoke has moved the driveshaft anywhere from 1/2 inch to 3/4ths of an inch from where it was and that's what he suspects is causing the vibration.

So it looks like a SYE is the best fix. Can I just order the SYE and turn it over to my guy or is there more involved that I have to order along with that?

96Cherokee113

If you install an SYE, you're gonna have to use a different driveshaft with a double cardan joint. People usually use a front driveshaft in place of a rear. Also, if you use another front in the rear, then if you're carrying a trail spare, you only need one since it's the same driveshaft front and rear.

BigJeepBigSnow

So I should just order an SYE kit and a drive shaft? If anyone has recommended sites please post. I was looking here

http://www.rockymountainsusp.com/driveshafts.htm

but I'm not sure which kit is best or which DS to get.

96Cherokee113

Just go to the junkyard and get a front driveshaft from another Cherokee. It will save you tons of money that you can spend on other mods

caged

i seriously don't think you need a slip yoke eliminator at just 2 inches. really, there must be something else wrong. don't waste your money, you're not ready for a sye yet.


even tho your u-joints feel tight, doesn't mean that's not where the vibration is coming from.
when you lift your suspension, the u-joints run at a new angle that they're just not used to. it may just be enough to give that vibe.

i say change out your rear driveshaft u-joints anyways. hell, you can try removing the rear driveshaft and plugging the output on the t-case and try running your jeep in 4 wheel drive by using just the front driveshaft to see if the vibration goes away.
i wouldn't suggest doing this for a long period of time, but it just might tell you if it's the rear shaft or not.

00jeepXJ

I am with caged...I have a RE SF 3.5" and the only vibrations that I get are when my U-joints are going out, Diff bearings, or Tires. If you want to spend the money on the SYE then go ahead but you might not need it.
00 XJ police
3.5 RE SF
31x10.5x15 Duratracs
limited front locked rear w/ 3.73 all around

Mike H.

Every Jeep is different and depending on the combination of driveline components different yet again.
When I lifted mine ('97, 4.0, ax-15, np231, 8.25) 2" I got vibrations.
I shimmed the rear axle, that was not a fix.
I replaced all ujoints in diveshaft, that was not a fix.
I installed a hack and tap SYE (budget), that fixed it for several years.
That finally wore out last year and I now run a proper short shaft conversion kit and the Jeep has never ran as smooth as it now does.

You said you will do an SYE, and from my experience that is a smart choice.
I agree with a post above that stated doing a x-fer case drop kit on a 2" lift is plain silly. With a small lift under belly clearance becomes critical off road. If you plan to stay low, you may want to look into TnT's belly pan which offers great protection and actually increases under belly clearance... think of it as a belly up kit.

BigJeepBigSnow

I've never heard of a short shaft conversion kit. Do you have any links that I can browse? I'm still learning this stuff.

And how could you tell the SYE wore out? What were the symptoms?

89cherokeelimited

A cherokee front driveshaft is to short for a rear.
I have some pics when I swapped mine.





When I had my vibes I swapped my t-case got a 231 stationary yoke and a custom made driveshaft after the swap not a single vibe and it's been almost a year since my swap out

kriebz

You've never heard of a U-joint, of course you've never heard of a short-shaft SYE. If you don't plan on going really, really high, you can probably skip the short-shaft, but if you have the money, it's probably not much harder.

Do you know if you have a D35 or Chrysler 8.25" rear axle? I have a '01, did a 2" BB, and had vibes just like you. I couldn't install a t-case drop... cross-member wouldn't budge. No, I'm not stupid. Bought a SYE and installed it in-place. It was easy, except having to cut the dirt shield off the existing output shaft and ripping out the seal. Point of no return.

I installed a JY front shaft for the rear, but it's too short (just like the previous poster's pics, more or less). I'm going to run with it for now, but I also plan on replacing the U-joints. If you have a D35, or a manual trans, the front shaft will definitely be too short, but there are alternatives (ZJ front shaft, custom).

So, you can try getting a pair of U-joints, since they totally won't go to waste. $11 at whatever store that doesn't suck. Don't bother going online. You need a small open-end wrench (8mm?) and all of 12 minutes to change one.

Oh... what kind of lift is in the rear? Shackles or tapered block will probably point your pinion up, which you should un-do with shims, until you install the SYE. There's zillions of SYE threads (and "I have vibes, oh nohs!" threads, for that matter), search.

(Jeez, drive an XJ for 8 months and you're a walking Jeep encyclopedia)

96Cherokee113

I've seen many people use a front driveshaft in the rear...but that was for a Hack n Tap. Might be different for a full SYE. Also, the front driveshaft won't work if you have a manual trans because the driveshaft is longer on a manual. I would've mentioned it before, but realized the OP has an auto and figured it didn't matter.

By the way, how much did the custom driveshaft run you?

BigJeepBigSnow

I have an 8.25. I see some full SYE and replacement drive shaft kits available online (ebay, etc) and I assume most of the full replacement kits would be matched to fit exactly, but of course, I'd rather find some cheaper ways of doing things. It's a 2" kit from rockymountainsusp.com with AAL's. I plan on replacing with 2" full leafs from OME if it starts sagging. I don't plan on ever going over 3" w/31's.. not much off-roading in my future but def light duty and lots of snow.

DagBMX

^if that's all you are doing with it, then a hack and tap would work for you, along with the front drive shaft and new joints. Iron Rock Off Road has a H'n"T kit that comes with a refurbished front drive shaft, the yolk needed, the 1310 joints, and you can order the drill bits and taps needed to do the job. comes with instructions and everything for about $200.
---->check it here<---click the link!

kriebz

Oh, yeah, a hack'n'tap will probably work great, and I realize you're right about the shaft length. I was less intimidated by ripping apart the t-case than drilling a straight hole in hardened steel, plus the added strength the "full" kit got me, but really, I doubt I need it. The hack'n'tap plus a JY pulled shaft would be the cheapest way to go CV rear, for sure.

BigJeepBigSnow: good luck with whatever you do. You're in almost the same position I am: newer XJ, 2" BB, fun in the snow and dirt roads. I was also eying 31s and OME leafs, but I think after spending on the SYE, I'll go cheap with bastard packs instead. If only it cheaper to do the front end right.