For several months now I've had a problem with the transmission (automatic) on my O6 Mustang Convertable. At low speed (15-25mph) the car will go very slowly, then very abruply shift (you can physically feel it like a bang or getting hit in rear). The shifting also happens sometimes when I'm at a stoplight with the foot on the brake, you can feel the car go into gear.(very slightly, not hard like above) At other times when driving slow, the car will rev up in spurts. Mind you this is in Drive. It does'nt happen all the time but it's occurring more than I'd like. I've had the car to the dealer, they actually kept it for a week and a half, drove it around and said "they could'nt find the probelm" ARRRRGHHH!!!!! The car has 83k miles on it and I'd like to know what I'm looking at here repairwise ($$$) and if anyone else has had this problem.
I don't get to come on this board very often but I've found over the past few years you folks have been VERY HELPFUL with information related to Mustangs & Ford products. I really like the way the board is organized, nice & easy to look for info. Thanks for you help & keep up the great work.

Mustang Ginnie from North Jersey.

 

Try changing the transmission fluid and filter before anything.

 

I recommend changing the solenoid pack. There is a TSB out there about the issue. It is not hard. Drop the pan, pull the filter, pull the pack, pop in the new one, replace the filter, replace the pan. Buy the special tool for filling the transmission.

 

That is a very good diagnosis ... Plus 1

 

Yea...i should have done that before my torque converter failed and snapped my trans shaft...i just recently found out that it could be an issue with your PCM...but that is almost a rediculous diagnosis...