Ive read through the forums and tips and fb pages and can't seem to see anyone else had the same problem.

Car has 140k drive it daily

Changed fluid and filter and fluid was nice clean color and no shavings or debris in the pan. Put matic J back in.

So heres the deal if i put the car in D drive and let it shift through the gears and when it gets to the final gear i will call it 5th gear if your just cruising at 60mph on flat roads it seems it has no issue, " I will stress this also it shifts fine through all the gears". But heres the kicker if you slightly give it more gas "while in 5th gear" the rpms will just climb all the way to 6k if you wanted it to but the car never goes any faster seems like its just slipping, im sorry this is hard to explain, but basicly while the car is in 5th gear which i think is overdrive or i guess when the converter locks up it slips while in that gear no matter if its in the manual/auto mode. But if you feather the gas and try to keep it from slipping you can acutally get it to take the gas and gain speed. Another note i tested is i took it out on a straight road and just floored it and believe it or not i got the car under wide open throttle up past 100mph in 5th gear or while its in drive but if you let off and try to cruise it pegs the rps. So......

I now keep the car in manual and in 4th gear just to keep the automatic trying to shift into 5th gear.

Any ideas or methods to this madness would be very helpful since my next move is to replace the TCM or try a used transmission.

 

It sucks you got no replies. Having the same issue.