I just want to give a confirmation on repair that I read in another thread on same issue. My 93 HDJ81 was "hunting " between gears around 50mph with slight throttle applied. My rpms did slightly fluctuate. Seemed more noticeable when first starting to drive. I did not have any transmission codes. I replaced the shift solenoids and that fixed it. I got my shift solenoids and gasket from Cobra Transmission. Much cheaper than Toyota!
Hope this helps.
Hope this helps.