Toyota Repair: 1987 Toyota Supra, 114k mi, 7MGE engine, 7mge engine, toyota supra

Question
Hello.  The automatic transmission (3 spd with OD) in my 1987 Toyota Supra (the problem just started a few days ago)has a hard time upshifting.  Sometimes it shifts up and down just fine, but other times (while accelerating)when I see that the RPMs hit about 4,000, I have to let off the gas and wait until I hear or feel the trans upshift, then I can keep on accelerating as normal.  The transmission downshifts fine and smoothly.

What do you think the problem is.

Thanks for your time,

Tony

Answer
I think that it's developing a transmission problem, if the problem was with the electronic control the O/D light would turn on and stay on or flash, this sounds like a hydraulic leak inside the transmission is developing which means an overhaul or replacement will ultimately be needed.