2g AWD automatic transmission problem. Why losing overdrive?

[96GSXMN]

I have a 1996 GSX that is 100% stock with no mods at all. I just replaced the engine in the car and finished it up. Well now I have been driving the car for a couple of weeks now and put about 500 to 600 miles in the car and now the transmission is acting up. This only happens every once in a while and is not a frequent problem. when the car is cold and did it once when I was running it hard. I will start the car up and take off. It will shift 1-3 no problem, its when it hits fourth the tranny goes into nuetral. I usually have to pull the car over turn it off, restart it and it the tranny works fine after that. Tonight (after the car sat for 6 hours) it did it again but this time I clicked the Overdrive button off when it did it and it went into third. I have checked the fluid and it smells good, not burnt, and is full. What is causing this? Should I change the filter (is this maybe a chance the filter is plugged) Now I heard there is something that goes bad with the Overdrive in these cars is this a problem assoiated with it. Also when I back out of my drive way in the morning and change gears (at a full stop of cource), The car goes into reverse with no hesitation. When the car a little gas the transmission gives a little buck and then it works fine. It does this every morning. What is this problem? Thank you for any help that can be provided
Garret

 

[darkiller_666]

I am having this same problem wondering if you ever fixed it?>

 

[emitsu97]

Bad end clutch. Had to have mine replaced a few years back. Common for the A/T's. Had a translab shift kit installed at the same time.

 

[FMFGSX]

IPT makes an end clutch kit, and Mitsu came out with a strong end clutch replacement kit. The end clutch control the 3-4 or Overdrive shift.

 

[darkiller_666]

Oh. Does the end clutches also have to do why my car feels like it is in neutral between gear shifts? If i WOT it the whole way it'll shift between gears fine, but if i WOT for part of the gear and then let off the gas, when i put the gas back on it'll free rev for a sec then catch.