Q. I have a 2002 Ford F-250 V-10 gas SuperCab truck with an automatic transmission. Because I tow a heavy fifth-wheel trailer up long grades, I had a transmission-fluid temperature gauge installed with the sender in the transmission pan. My local Ford dealer cannot tell me what transmission-fluid temperature is considered the warning temperature and should not be exceeded. Can you please tell me the following: At what temperature should I start being concerned? What do I do when the temperature actually gets that hot? Should I pull off the road and idle, or pull off the road, open the hood and shut the engine off for a while?
— B.T., Woodland, California
A. You should not exceed 275 degrees F. As you approach that temp but before it actually reaches it, you should ease off the throttle and slow down. If it reaches that temperature, you should find a safe place to pull off the road and let the engine fast idle with the transmission in Park. This allows the fluid to circulate.
Ken Freund’s more than three decades of auto-repair experience and 20-plus years of RVing helped him author numerous books and articles on vehicle repair. In addition to RV Clinic and Performance, he writes the Powertrain column in MotorHome magazine. Ken has been a California Automotive VO-Tech and Smog-Test Program Instructor and an ASE-certified Master Automobile Technician.