4 WD Four by Four

My Grand Cherokee ZJ spec:
Manufactured : 1998 (the latest model)
Engine : 4.0 litre I-6
Trim : Laredo
Modification :
- lift 2”
- 31” tire
- After market shock and coil springs (OME)
- After market sound system.

List of problems and solutions:

1. Front ring and pinion failed at 9,000 km. Symptom: noise from front differential. Solution: change the ring and pinion with the higher spec. This problem was common for latest version of Grand Cherokee ZJ.
2. Air conditioner evaporator leaking at 25,000 km. Symptom: lost of refrigerant, AC not cold as used to be, the compressor clutch on and of frequently. Solution: inspect the evaporator, clean it. Found a big hole in the evaporator, could not be repair, then change the evaporator. Note: the evaporator made by Zanden, the size is relatively small compare to ZJ interior volume. The evaporator was located under the dash board, to uninstall it you need to remove the dashboard first.
3. The master power window and central lock (on driver side) failed. Symptom: completely failed, no button functioning. Solution: Check the 30A fuse on the power distribution center under the hood, take it off and then put it back again. Usually the power window will work again normally. For better solution: make an on-off switch between the power window and the fuse, and turn off the electric charge when it not functioning. It is a common problem in Grand Cherokee ZJ, a continues electric supply to the central power window and central lock unit can make the system failed.
4. Air Conditioner compressor failed at 38,000 km. The symptom almost the same with number 2, however usually the AC works fine at the beginning and failed after 1 hour trip (when the compressor reach its normal work temperature). Solution: Inspect the AC compressor, check for leaking. In my case, I open the compressor, overhaul it, and found most of the piston have been scratch badly, and some parts of the clutch have been damaged. I change the compressor completely. Note: My original compressor brand is Nippon Denso (ND), it is weird because the evaporator is manufactured by Zanden.
5. Transmission high pressure hose leaking at 47,000 km. This is the high pressure hose from the tranny to oil cooler, leaking on the oil cooler side. Symptom: oil leaking and then dripping from the hose, loosen transmission oil, when the condition become worst, the automatic gear can jump suddenly to neutral in normal driving condition. Solution: change the high pressure hose, add the transmission oil. Note: to check your ZJ transmission oil level, park your car in flat area with engine running, move the gear lever to N and check the level using a dip stick.
6. Engine misses throughout driving speed range starting at 51,000 km, the jeep engine misses in high rpm (i.e. above 2000 rpm). This problem occurs especially when driving a long trip. Solution: clean up the fuel tank, clean the fuel pump. Replace the fuel filter. Note: for my ZJ the fuel filter located inside the fuel tank, for pre 1998 ZJ, fuel filter located outside the fuel tank (more simple and easy to replace).
7. Death Wobble, occur several times after I lift my jeep 2” and changed the stock tires with 31” tires (see my previous post). Solution: proper wheel alignment.

The rest are minor problems, like death battery, dirty power window motor. Generally the I-6 engine is very reliable and low maintenance.

See my other post about my ZJ compare to the Japanese 4wd in Cars and Bikes site.