new XJ owner

I just bought a 92 XJ 4.0L 5spd with 200k miles on her and before I start upgrading, I was hoping someone could tell me some of the common problems that need to be fixed or at the least looked into. Thanks a bunch Jeff

Folks in this forum are going to tell you to do a search 'cause this question has been asked before, but since I bought my 95 XJ last year here's what I've HAD (not wanted) to do:

Repair TC - $600 (for rebuild and install - if I had to do it again, I would do it myself for a lot less.)
Shift linkage repair - $90
New CD - $100 (cassette was shot)
Tune up - Less than $50 for wires, cap, plugs
Door hinge repair - $90
Transmission lines - $50 (to cure smoke from leaks - replaced connectors and rubber lines)
Tranny pan leak - $50
Radiator - $130 (to cure overheating problem)
Power window wiring - (free, if you have wire and tools and time)
Rear light wiring (ditto)
General touch up of paint - several rattle cans at discount store

I also replaced the exhaust system which was on its last legs - $200 and bought new tires at $57 a piece for four to replace the rim protectors it came with.

In short, there are the typical problems you'd expect in an old vehicle, but this is a fun truck to work on and the parts and labor are pretty cheap.

Have fun.

First off I'd do the following:
All the fluids, both diffs, transfer case, tranny.
Diffs take 90W gear oil. If it's a limited slip rear you will need friction modifier or use valvoline synthetic, it has the modifier already in it according to the bottle.
Transfer case, I use mobil-1 atf
Tranny, AX15, takes GL-3 [not GL5 or GL3-4-5] GL3, either dealer supplied or from redline, about $11 a quart for redline, $18 from the dealer, your choice.
Engine, I have always used Mobil1 10W30 and either Mobil-1 or K&N filters.
Cooling system, I'd drain it, refill with water and add either prestone or zerex 7 hour flush, then add the prestone back flush kit and back flush it, drain it, refill with 50/50 mix of prestone and DISTILLED water. At this time you might want to replace all the hoses, tstat and pressure cap. I'd go with OEM hoses, they fit and the heater hoses come prebent and have clamps already on them, the lower rad hose has a spring already installed from the dealer. OEM thermostat has a bleed hole in it, that goes to the 12 O'Oclock position when installing. Remove the overflow bottle and clean it out.
Other considerations, new serpentine belt, plugs, cap, rotor, wires, air cleaner. From there I'd pull the wheels and check the brakes, replacing the front pads takes about 1/2 hour from start to finish if you don't dawdle..
Start removing grounds and clean them up, all of them, use a brass brush and clean the ends and the mount point, use some dielectric grease when reinstalling them.
Handy tools to have, floor jack, two or four jackstands, KrikitII belt tension gauge available at NAPA, good set of Torx sockets.
Theres a weekend, let us know when you want more to do.... and welcome.

I second all that Rich said, that's just the stuff you do when you get a used auto, to "reset" all the maintenance counters so you know when they were done.
I would also recommend that you go through the entire front end. Jack it up and check for play in everything. At 200K miles I'd be willing to bet some of the TRE's may be shot, the same goes for wheel bearings and bushings. You don't want to experience death wobble.
I'd also check if the shocks were alright, of course if you plan a lift then you might want to hold off on replacing those.