Not going straight

Hi,
1993 XJ 4.0 auto 134,000 miles.
If I let the steering wheel go the Jeep will veer off to the left, nothing dramatic but it does not keep going straight ahead. I had the tracking adjusted on a 4 wheel laser tracking rig, no difference. If the road camber is leaning to the right then it will run straight. Any ideas as to what might be the problem I'd like to hear from you.
Thanks in advance

Cherokees are set up from the factory to track straight on a crowned road. If you search on the wheel alignment stuff, you can find that the rear axle is actually mounted so that the wheelbase is about 1/8" different from the right to the left.

Thanks for quick reply, that sounds like what my problem is and why tracking has not corrected it. I will have a read up on tracking and see if there is a solution. Thanks again.