I just bought a 2000 Jeep Grand Cherokee Limited for occasional use. I am not familiar with 4 WD vehicles so I would like to know what kind of maintenance these need, and, what things tend to go wrong on a Jeep Cherokee. After purchase, I had the engine oil changed and also the oil in the front and rear differentials. The transfer case oil seemed to be OK.
Peter.

This is a very complicated question you ask. It depends so much on driving conditions and how long it sits between uses.

I had an older Larado version with the 4L and it ran for a long time with no trouble. Trying to predict maintenance troubles is a crap shoot so offereing advice is risky.

In my experience with 4x4's the u-joints, front cv shafts are the first real maintenance besides normal wear and tear on shocks, brakes, and such.
On my Larado I also had to replace the in-tank fuel pump, a harmonic balancer, and a fuel pressure regulator. But it was traded in at 274K miles for half as much as I paid for it.