91 Taurus Wagon 3.0 Transmission

My transmission has suddenly developed a shifting problem. When I first start out each day (cold engine), the car shifts smoothly and quietly. Then, after several hours of use if I stop the car and shut off the engine to run a quick errand the problem starts. The car starts out from a dead stop and the tacometer goes up as high as 4,000 and it wont come out of first gear. I briefly shift it into nuetral and back to drive and it will shift to the next highest gear and no problems after that. Then at the next stop the problem happens again and it sticks in first gear. The fluid is new and so is the filter and it's on the full line on the dipstick. Other than this first gear problem the transmission seems fine. I never have problems with down shifting. Do you have any ideas for me? Thanks.

Don't be offended here, but I've got to ask, you are checking the fluid level with the transmission up to temperature and the engine idling in Park, right? Many people don't realize this is when the tranny fluid level should be checked. If you are seeing "full" when the engine is off, you are low on fluid and that may be contributing to your concern, especially if this issue just started after changing the fluid and filter.

-Rod

Rod,

You're correct. I usually check it cold. It must be low. Thank you. I'll get back to you if your suggestion does not work out. Take care friend.