Questions and Answers

Ford F250 Hunting For Downshifts Q. I have a 1999 Ford F250 Super Duty 4X4 Diesel with automatic transmission. When I go highway speeds, say for maybe an hour, and then start to exit the highway and slow down the transmission make a high pitch sound like it can't find the lower gear to shift into. If I just accelerate then it goes in gear and comes down fine. Do you have an idea what could be causing it to miss the gear? Thanks, Dan

A. It sounds like you may have a sticking or bad shift valve/solenoid. You can run a self diagnostic on the Automatic Transmission Control System but you will need a scan tool to access it. Ford does not provide a procedure for reading diagnostic trouble codes without a scan tool.

I don't know what kind of maintenance you have done with the transmission, but a transmission filter and fluid change would probably help if the problem is caused by a partially clogged transmission filter. Do not get a flush, just replace what fluid comes out with the filter.

Be sure to use the Motorcraft MERCON ATF only.

Using a transmission fluid that indicates a dual usage MERCON and MERCON V in a transmission application requiring MERCON may cause internal transmission damage. The use of any fluid other than the recommended fluid may cause transmission damage.

Some fluid labels may indicate dual usage such as MERCON and MERCON V. These dual-usage fluids are not to be used in transmissions that use only the MERCON type fluid. These dual-usage fluids may be used in transmissions that require MERCON V use.