I am new to the jeep game. Just picked up a 97 TJ a few weeks. I have a stupid question. Does the front drive shaft (4wd) turn on your units even thought the jeep in is 2wd on the shifter. I noticed a low rattle as a I am cruising a low speeds and had some one watch me as i went by to see if the shaft was spinning. It was an I believe this is the source of the noise. If this is normal fine, if not what do you think the issue may be.

 

Yes it turns even when your in 2wd. The noise could be the joint at the front. Check it could be loose, make sure the little bolts (4 of them) are tight (don't over tighten) that hold it on a 8mm wrench will do the trick. Other than that unless u picked up some dirt under the brake protect shield and its stuck in there making the noise.

 

Jack up the front of your jeep so the front tires are off the ground. Then rotate your tires to determine the source of the noise. It could be the u joints or CV joint on the driveshaft causing the noise. I just had a similar problem on my 03 and it was the cv joint between the 2 u joints at the rear of the front drive shaft.