Question: I have a transmission problem on my 1992 4WD Ford Explorer. When I go to pass on the highway at full throttle, acceleration is all right, but then the engine revs high like power is no longer going to the transmission. I've changed the transmission fluid and filter. What's the next step?

Answer: Get it to a transmission shop or dealership. The transmission is slipping, which is most likely caused by an internal failure (bad clutches, clutch pack seals, fluid pump, torque converter, etc.). The techs can scan the system and run hydraulic pressure tests to narrow it down. If it is an internal hard-part failure on a high-mileage unit, you're usually better off going with a complete rebuild. In my book, the best rebuild is an official manufacturer rebuilt unit. It may cost more, but they not only replace all worn-out parts, they apply all TSBs and new production modifications, which can make your new transmission as good as it gets.

If you have a technical question regarding your pickup, SUV, or van, feel free to contact Alex, a master technician with the National Institute for Automotive Service Excellence. Send a letter to him in care of Truck Trend Garage, 831 S. Douglas Street, El Segundo, CA 90245, or e-mail us at Please include the VIN with your question. Due to the volume of questions received every month, we cannot guarantee that everyone's question will be personally answered or will appear in the magazine.

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