95 Lumina bucks at 45 - 55 mph after car is warmed up and driven for about 10 minuntes. What should I do first to fix the problem. Thank you for any help.

like most when you discribe buck/miss you need to check the basics.when was last tune up??how many miles??? like most you dont mention miles/engine & what has or has'nt been done.it maybe a plug/wire that is breaking down when there is a load on engine.check the basics & let us no
is the ''engine lamp'' on???

The torque converter clutch (TCC) is known to produce such symptoms. Not good news if it is because it requires removal of the tranny to get to it. Also, I've been told that a bad TCC is indicative of other major problems and it's better to just replace the transmission altogether.

If you have a "check engine" light on, there is (surprisingly) a code for this. My '95 is having TC problems as well, I think, but I have no light.

Check the basics first of course.

A scan using a trans function scanner will reveal if the TCC is the culprit here, this will reduce parts/guess work.

A scan using a trans function scanner will reveal if the TCC is the culprit here, this will reduce parts/guess work.

This is something I would like to do as well. Do I have to take it in, or is there a cheaper way similar to the Autozone method? Does the scanner plug into the OBD or is there another port. Mine is the last year before OBD II became standard, would this be a problem?

A specialized scanner program is required, most trans shops have this, no AZ is useless here.