1999 jeep cherokee does not track but wanders at highway speed

have you had the computer checked

yes it could be

Well first, is the overdrive on or are you in the overdrive gear, also sorry to tell you but these v-8 jeeps get real bad gas mileage, i think highway mileage is 18 and city 14,if you were getting better mileage and the trany is actting up then that will cause the lower mileage, good day.

1. out of balance tire because it sounds speed spacific.
2. worst of all! Loose lug nuts or possibly loose spindle nut. (you will need to lift the wheel off the ground to tell)
3. worn linkages i.e. ball joints, steering linkage, anything that would allow play in the front wheels.

Computer controlled transmissions can get confused at times, from my personal experience. If the problem doesn't happen again, I would ignore it. If it happens all the time, it's most likely the transmission computer. Other things could be the shift linkage, engine vacuum leak, speed sensor, etc... Hope this helps.

try to change the bearings

jeep has a problem with the vent doors (which allow heat or cold air to pass into the passenger compartment) these are plastic vent doors, that break very eazy...the dash has to be removed to replace the broken part, which makes this a big dollar item. have both doors replaced, not just the broken one.....sorry...this will be over $500 to fix,

The Jeep has steering idlers (short 7" arms) that eliminate wandering. Sounds like they are worn but FIRSTLY check that you have 4 identical tyre pressures as just one tyre front or back being low will give you the wandering sensation in a 4x4

Regards

Lloyd

defective pinion bearing?

it sounds like you may have a missfire which could be caused by faulty spark plug or ignition leads i would check these first