96 Monte Transmission issues

Well I purchased my monte about 6 months ago and noticed that the transmission was shuddering on the highway when I would put a load on it going up a hill or passing another car. It would also fall out of gear when I would slow down to make a turn and then ease back on the accelerator to accelerate. And of course some days were better than others it would run fine for a while and then all of a sudden right back to where it was before. Before I get to crazy with this thing it sounds like it could be something as simple as replacing a sensor. Any input would be greatly appreciated.
Thanks, Mike

Also vehicle has about 107,000 miles on it, I bought it for a 100 bucks and it runs great with great gas mileage except for the tranny issues.

Welcome to AF, many things can cause this, a full scan with a trans function scanner will reveal any slippage errors or solenoid issues and/or pending trans codes, anything else will result in guess work. This assumes the trans fluid is not burnt and full, of course.

Thanks! I think Im just gonna take it up to the gm dealer and have them throw the OBD on it that way I can take the guess work out of it. I did drain the fluid and replaced the filter...I know how that can sometimes make it worse! Just not too sure when it comes to transmissions especially an electric one at that. Thanks...will update when I find out what the problem was.

Well I checked it out with the obd and it threw a code for the torque converter solenoid stuck open (742). What should be my next move? I know this is probably caused by sediment in the torque converter and I am wondering if a flush and fill would actually work or make it worse! Need some input...Thanks Mike

Don't fllsh the unit, a full scan can command the tcc solenoid and confirm whether it works before the difficult job of replacing it.

Flushing will make it worse,all the dirt,metal shavings and clutch material go inside the valve body during a flush.I know a transmission shop that does lots of valve body cleanings and rebuilds due to flushes done.