I have a YJ with the TJ front axle shafts (one peice passenger shaft) and the front drive shaft (unbalanced) causes a vibration above 60 mph. It is also a bit short for the application. The jeep has a BDS 3.5 inch lift, and a 1" shackle lift. Is this too much lift for the stock front driveshaft? The options are to lengthen and balance the driveshaft ($100), or get a new double cardigan shaft (transfer case end, $269). I would hate to get the shaft balanced and lengthened, only to have the vibes remain.:confused:

are you sure its the front drive shaft? do you have a short shaft kit in the rear? usually when lifted, the YJ's will have a vibration from the rear driveshaft becasue of the u-joint angles. does the front vibrate more when its in 4x4 or when its in 2wd? do you have a transfer case drop kit?

If you're sure its your front DS I'd just have it lenthened and balanced. While your at it I'd upgrade to a larger diam tube on it as well. I went with a 2" tube on mine. Stock is 1-7/8th if I recall. You'll have to replace that section anyway so why not?

It is the front shaft, I have an sye and cv shaft in the rear, and the pinion angle is lined up with the shaft. If I go with the cv shaft in the front, will I have to shim up the front to get the pinion angle less than 3 degrees, or can I leave it at the stack angle? There is no tc drop, but there are no vibes at all with the front ds removed.

You are best off getting a CV shaft for the front. At 3 1/2 inches of lift, you are pushing the limits on a standard driveshaft. Don't mess with the pinion angle on your front axle, that will throw your caster and all your steering geometry off, creating all kinds of NEW problems. Then later when you are feeling rich you can have your old driveshaft modified and have it for a spare.

...a new double cardigan shaft

Is that a driveshaft with two :rainbow: sweaters?

why yes, it is, maybe I meant cardan, but I'm not really sure:flipoff2: :flipoff2: Any other constructive input? Does anyone have a yj with 5 inches of lift, tj axle shafts, and a stock yj driveshaft?

I was wondering the same as I still have the stock front DS and a 3.5 in BDS lift. It is showing some of the shaft more then stock. Hmm next mod may be a new longer thicker balanced front shaft just so I don't pull it out when flexing.

I'm running the stock driveshaft in my YJ with a SOA and 2.5 inch springs. I had it balanced and haven't had any problems with it. It does sit out a little further than stock but when I asked my driveline people about it they told me not to worry about it as long as the splines don't show at any time.

they told me not to worry about it as long as...

...your suspension doesn't flex.

It's definetly your front shaft vibrating. Ok, not definetly, but I would be willing to bet $$$. Those TJ shafts spin the whole front axle assembly so now your DS spins where with the disconnect, the shafts weren't under load. Think about when you lift a vehicle off the ground and spin the tire, the other side spins the opposite direction, but the drive shaft doesn't spin at all. That's what the inner shaft on the disconnect side USED to do.

Take the shaft in and have it re-tubed and balanced. When you take it in, give them measurements of your current set up. They'll be able to tell you if it should be longer or not.

I wouldn't put a CV shaft on there. It's an expense you don't really need. The HP on a YJ D30 gives you enough room to work with. Add to that the fact that a new shaft would cost ~$75 (assuming you can pick up a used TJ/XJ/Explorer shaft), lengthening/shortening/balancing $50~150, the CV yoke for the T-case $25~50. You're into that thing for $100~275 and you really didn't need to.

Does anyone have a yj with 5 inches of lift, tj axle shafts, and a stock yj driveshaft?
Yup...6" lift and locker, so basically the same as tj shafts... and I agree with Butch. Ya don't need a CV up front. Just get it balanced. A stronger tube is not a bad idea, but thats up to U. U could even have them do a long travel slip, but again, its just how much ya want to spend/put into it. Mine's stock and works fine.




WoRM :jeep:

I got the shaft balanced and lengtened, and the vibes are gone. Thanks for the advice.