I have a 1997 F-150 SuperCab, 4WD, 4.6L V-8, automatic transmission with 83,000 miles. Over the last 6 months the transmission appears to kick out of gear (overdrive) and will, within a second, kick right back in. It happens most often when the truck has been driven (hightway) for 2-3 hours straight. Less when it is very hot outside. My Cruise Control recently failed. I thought that the VSS might be the problem re both issues. I replaced the VSS last night. CC still doesn't work. Don't know about the transmission "problem." Did not feel like going for a 3 hour drive last night. What else aside from vaccuum lines (I think I checked all of them last night) should I look at? BTW, I serviced the transmission about 5 months ago - after I noticed the first transmission hiccup.

Thanks!

 

It isn't vacuum lines. There are no vacuum lines that connect to the transmisison.

It is the Transmission Range Sensor. It's mounted on the driver's side of the transmission, where the shift cable attaches. As this sensor starts to wear out it sends a false signal to the PCM that you have moved the shifter to N. The PCM doesn't know this is bad info, so it shifts the transmission to N! The fault usually lasts less than a second, so it goes right back into gear.

A new sensor should be just over $100 installed, quite a bit less if you do it yourself.

Mark