New XJ Owner: Drivetrain Slack??

I just bought a 97 XJ and have noticed some slack in the drivetrain when taking off from a dead stop. I got under the rig and tried to manually twist the driveshaft to check for U joint slack and it seemed tight. Any thoughts would be great.

This one seems to come up from time to time but I can't find anything in the archived threads and I'm too tired to search very long. So here goes:


I'm assuming that your Jeep is totally stock? If yes, try this:
Get under it and look towards the back where the driveshaft attaches to the pinion on the rear axle. It is held in place with 4, 8mm bolts. There are 2 bolts on each u joint strap. Take them off. At the transfer case end of the driveshaft, you will see a rubber boot (slip yoke). This boot allows the driveshaft to "slip" when braking or under acceleration. It gets really dry in there and since there's no zerk fitting on it, you must take the driveshaft off and lube it yourself.
The u joint at the rear axle will be a little stubborn so I have used a big screwdriver to carefully pry it out of the pinion yoke. Take care not to have a cap fall off a u joint. Some people will put tape on it and wrap it in a 3 o clock to 6 o clock fashion if you know what I mean? Then all you have to do is pull on the driveshaft and it will come off (rubber boot and all). You will not have to take anything else off. It might look like you do if it's really being a PITA. The driveshaft has a bit of girth to it so be careful you don't hurt yourself when removing it. When it does decide to come off it can do so quickly.
I put a liberable amount of grease down in the boot. Same kind you would use for tie rods/ball joints. Then...slip the boot end of the driveshaft back into place. Go back to the back now. The manual does say to replace those u joint straps each time they are removed. I have re-used them in a pich but they are probably less than 5 bones at NAPA. Those 8mm bolts do not get tightened all that much. IIRC it's about 5 ft lbs. I don't use a torque wrench on those but I'm careful not to overtighten.

That's about it. It's an odd sound/feeling that thing makes when it's dry isn't it? Good luck. Welcome to . This is a great place with great people.

Almost forgot. Make sure you mark (with white out or a Sharpie pen) the driveshaft to the pinion yoke so that you're sure it goes back on exactly the same way it comes off. This way you know you don't fawk with the balance of the driveshaft.

-river

Thanks so much! I will get on that this weekend. I got pretty lucky(So far..) on this XJ. I rolled under it on my creeper and there was not as much as a ding in the underbody or frame. It is so clean that all of the labels on the tranny, xfer case and diff's are still intact. But NOT FOR LONG! lol Thanks again.
PS: How do I I.D. my diff? I would like to know if I have the 8.25 the 35 or the 44.

D35 is more rounded on bottom. 8.25 is flatter. Check this out:

http://www.yuccaman.com/jeep/gear1.html#axle

if you plan on discoing the rear drive shaft remember to set the ebrake and block the wheels.... if you don't do this you will not forget the next time you need to remove the drive shaft. ask me how I know :nono:

Whenever I'm taking out one driveshaft or jacking up one end of the truck I put it in 4Hi and leave it in 1st.