One problem related to brake drum wheel cylinder has been reported for the 1998 Jeep Grand Cherokee. The most recently reported issues are listed below.
1. Fuel injector failed causing the engine to misfire and operate on only 5 out of 6 cylinders. 2. In the same cylinder (#6) rod broke, causing engine to blow and need replacement at only 42,000 miles. 3. Power steering pump almost fell off the vehicle. (most likely due to improper installation after engine rebuild). 4. Brakes constantly squeak or make grinding noise when pressure is applied. When temperatures are below 50 degrees, a high pitched whinning noise is heard from underneath the vehicle. Can only be heard when traveling under 45 mph - due to road noise masking the sound. (multiple dealers have not been able to determine what the problem is nor be able to fix it, so constantly whines). 5. Fuel gauge fluctuates when 3/4 full (drops to empty and fuel light turns on, then returns to normal reading. Will continue to do this until tank is 1/4 full). Told this is a problem with the fuel sensor. 6. Transmission is occasionally rough (jerky shifting between 1st and 2nd gears).