94 YJ U-Joints

jgermann · #11 08-06-2008, 07:21 AM

OK, I have taken it out before when I had to get the t-case rebuilt and then again when I replaced the clutch and didn't notice anything but when I was reading in the Chilton ( i think thats the book I have), it said to mark it and make sure it goes in the same way it came out for the balance. I just wanted to make sure I wasn't going to screw something up when I take it out today after work. I just have bad luck when it comes to these things.

Thanks for the help....

Jim_Lou · #12 08-06-2008, 07:36 AM

There probably are a few manufacturers that balance the shaft on the vehicle - It would make sense perhaps on a Rolls or Bentley or Mercedes limo - but I can't imagine Jeep doing it. On a Jeep I can't imagine ever being able to tell the difference driving down the road. Heck, I've never bothered to balance a driveshaft and lived to tell about it.

CJDave · #13 08-06-2008, 07:50 AM

I have never heard of such a thing.....

Are you sure they were not alluding to the position of the slider....since you CAN pull it out and rotate it 180 degrees and re-insert it, that might be what they meant. I can easily see how that could be a problem.

LEVE · #14 08-06-2008, 09:42 AM

If you look at the drive shaft, you'll see weighs welded on the outside tube. You bet it should be balanced... if you want a long service life out of it.

Now that you've lost the orientation for the splined shaft to the tube, you're kinda sorta out of luck. I've been successful in looking at wear patterns of the splines and the tube. By seeing what pattern was the tightest and slipping the shaft into the tube with that orientation, it worked. But, I could have just been lucky. Now I spray paint the shaft and tube to maintain orientation when I have to divorce the parts.

Otherwise, if you're really concerned, take it to a drive line shop and have the balance checked. It's worth the money for piece of mind.

Jim_Lou · #15 08-06-2008, 09:42 AM

Talking about a shaft with the slip-joint between the yokes, I take it? Rotating it 180 shouldn't bother anything, but 90 degrees out would be nasty. My driveshafts aren't keyed, so they can go back together on any spline.

I don't know that any manufacturer balances driveshafts in the car, but it wouldn't surprise me to hear that the really top-end vehicles were done that way to get every possible vibration out.

Remember the on-car tire balancers that fastened to the wheel which was then spun with an electric motor? They worked fairly well in the era of skinny tires.

Pete88YJ · #16 08-06-2008, 10:58 AM

A one-piece driveshaft like a YJ rear won't matter -- just put it in the transfer case output and it should be fine.

If you have a 2-piece, with a spline in the driveshaft, it is important that it get put back together on the correct spline - so the front and rear ujoints are in phase correctly.

Glad it all worked out ok.
Pete