Transmission issues

[Lakeside]

I have a 1997 Grand Prix GTP. Sometimes it acts like the transmission is going out and sometimes it shifts just fine. How do I determine what transmission I have. The 4T65E or the 4T65E-HD? Any info would be appreciated. If you turn the car off and then restart it, sometimes it will shift just fine for a little ways.

[Zef_66]

I have a 1997 Grand Prix GTP. Sometimes it acts like the transmission is going out and sometimes it shifts just fine. How do I determine what transmission I have. The 4T65E or the 4T65E-HD? Any info would be appreciated. If you turn the car off and then restart it, sometimes it will shift just fine for a little ways.

GTP = 4T65E-HD

Have you checked the transmission fluid level? And when was the last time you changed the fluid and filter? How many miles?