We have a work truck that driving down the freeway it shifted down a gear for no reason and then the tow/haul mode light started flashing. This lasted about 5 minutes and then it shifted back into overdrive, the light quit flashing, but stayed on. When we pushed the tow/haul mode button it shut off and it seems to be working as normal now.

We werent towing anything at the time that this happened, any ideas?

Truch has about 90,000 miles, all services are up to date, we run full synthetic in the tranny.

Leon

 

I was told, ( I never had the problem) It is a selenoid in the tranny.

I am not sure, but figured I would say what I know here for you.

It almost seems like like maybe a connection to the selenoid, and it corrected itself though?

 

There should be a fault code stored. The flashing T/H light indicates a tranny fault.

 

Check the VSS on top of the rear diff.

 

Read the codes and there were (4) and they all had to do with the EGR valve, nothing with the tranny.

What is the VSS that I should check? Sorry for my ignorance.

 

Just noticed this - there is only one fluid approved for the Torqshift - Motorcraft SP. What fluid are you running?


Just like he said, you'll find it in the top of the rear differential. It is the Vehical Speed Sensor. I can't tell you how to test it, but you could check it for a loose or corroded connector.