I had my trans fluid changed, just a spill and fill at 121k miles. (I have 122k now) When I checked the dipstick after, it always showed it was over filled. I tried testing hot and cold in and out of gear, and still showed over full. The mechanic said I was doing it wrong and presented me with the dipstick showing on the mark for hot. I didn't see how he did it but felt so stupid I just took his word. Further the trans was acting ok so I just went with it. Then a few months later when the weather got warmer the trans would sometimes shudder when taking off from a dead stop, but only after achieving normal operating temperature. Can overfilled trans cause such a problem and or damage? Will correcting trans level help? How do I properly check trans level? When I check it cold and car has been sitting for days dipstick shows almost 2 inches above the highest hot mark??...What would you do??