`89 Cherokee 4.0L, automatic, about 154,000 miles.
Occasionally at speed the Cherokee lurches and there's a bang from the drive train. This only happens in warm weather (above 70F or so), at speeds between 30 to 60, and it _seems_ to happen when backing off slightly on the gas to feather speed down a point or two. I'm told that this is the torque converter unlocking and then relocking, but it isn't as smooth a transition as when it normally locks or unlocks for overdrive, and doesn't happen at a logical shift point, engine-wise. It happens on its own, there's nothing that I can do from the driver's seat to force it to happen, and the position of the power/comfort switch makes no difference. I've had this Cherokee about 3 years and it has done this little trick for as long as I've owned it -- but only in warm to hot weather.
Is this a computer malfunction? I gather from other threads here that the computer controls the shift to overdrive. And, I have my suspicions about this computer anyway, as it emits an RF signal that crosses into the FM radio antenna lead and produces a scream at empty FM channels -- but since it is an a PIA location behind the dash I'd like to be reasonably sure that it is actually the problem before I go pulling it out.
Anyone run into this problem before?