I keep coming across this concept while reading about towing. It seems to be a good thing to do when climbing. What does it mean and how do you do it?

I have a 2006 3500 CTD, auto, 410, hauling a Lance 1121 slide in camper and towing a Wrangler.

Thanks for the info and any insights.

 

It is installing a switch to force the TC to lockup. Lots of the auto guys have them and love them. The link is actually spesifically addressing the 04.5-05 trucks, but I believe you have the same tranny. The third gen guys should be able to help you a little more with whether you have the same tranny .

https://www.dieseltruckresource.com/...=lockup+switch