Truck started acting funny about two weeks ago, It started by not shifting into overdrive while i was pulling a trailer(5500lbs). Stopped turned the truck off and waited couple min. turned the truck back on put in drive and was on my way with no more problems. It did it again couple days later w/ no trailer, turned it off and back on every thing fine. now if i am on the highway it will never slip or anything, but if i am going stop light to stop light it will shift eractic, and now turning the truck off and back on dose not help anymore. as long as i can get it on the highway it is fine, but it sucks to drive it in town. If you have any insight please help.

can anybody help?

Sounds like the fluid is thinning and leaking past a worn TCC solenoid valve and bore. This is very possible. Especially for a 1993.