Three problems related to transfer case have been reported for the 1999 Jeep Wrangler. The most recently reported issues are listed below.
Driving my 1999 Jeep Wrangler sport 4. 0 l6 5-speed manual at appx. 65 mph a slight vibration came from the gas pedal. I pulled over, after crawling under the vehicle I found the front drive shaft loose at the joint connecting to my stock np231j transfer case. Figuring it was just a worn u-joint I continued on my way at a much slower speed appx. 35 mph for about 300 yards there was a loud pop along with metal and dirt flying from under the Jeep which made me pull over once again this time out of control and ending up in the ditch. Where I found the np231j shattered in 5 pieces, many more were thrown onto the road way.
Transfer case failed.
Transfer case failed.