Have a problem with the torque converter on your motorhome or tow vehicle not staying locked up? Check for a faulty brake light switch or throttle position sensor.
Any time you tap the brakes, the brake light switch sends a signal to unlock the converter, so if it’s faulty your torque converter will act up.
A faulty throttle position sensor may be the cause of your problem especially if the symptoms seem to be heat sensitive since it is positioned where heat builds up that can damage the sensor and or wires.
The torque converter subject seems to always be brought up. I understand the main reason for not towing in overdrive is the up and down shifting in and out of that gear with the corresponding in and out of the torque drive, thus causing excessive transmission heat and wear and tear on such resulting in transmission failure. Always towing in ‘tow mode’ will lock out overdrive and extend the other transmission gears shifting points but your vehicle will never shift into Overdrive.
I should have been more explicit. The idea for the tip came from something I read. The RVer had a pickup tow vehicle and complained that the torque converter would not stay locked. He said the converter would just unlock seemingly with no reason then almost immediately lock up again. It happened both in overdrive and out of overdrive. There was more to his description but I can’t remember. The suggested solution from the RV tech was pretty much what posted as the tip.
Steve, does the comment from Greyhound mean that if your tow vehicle has tow/haul mode it should not allow shifts into overdrive? I had always understood that if the road & load conditions permitted it was OK to let the transmission shift into overdrive as long as it stayyed there and did not search for any other gear. Appreciate your response, Mike
I don’t know Mike. My Dodge V10 has a switch that allows me to turn off the overdrive manually. I can’t tell if activating the switch also makes the torque converter act differently though.
When I start the engine overdrive is on by default. I have to remember to switch it off when driving conditions… hills or strong headwinds… wont let overdrive stay in lockup. On level ground and no headwind or on a decline, I can and do drive in overdrive.