Because if ya have a pulley and a custom tune...sometimes if your truck shifts into OD while in WOT you will have a nice big hole in your block where your rod was "flung" through it....This is because we have OD lock up on our torque converters...

 

That is what everyone should be doing, letting that tranny shift in and out of OD causes massive heat in the tranny and what does heat do to a tranny it destroys it so if your not going fast enough for it to just stay in OD even when you apply some throttle the leave the OD alone

John

 

Actually, that's exactly wrong. Engaging OD does not cause a lot of excessive heat, but unlocking the converter does. I still say it's an almost useless button and I'm very glad we finally eliminated it on the 5R110.

G

 

so pretty much the story is leave it on and DON'T TOUCH THE BUTTON?

 

so if the tranny is shifting in and out of OD allof of the time as your driving because your not driving fast enough to use that gear there is no heat build up?? ok im from washington and we drive the mountian passes all the time pulling a boat now if the tranny is doing the in and out of OD under a good load is that where you cause all the heat then

John

 

As far as heat is concerned, I think what Factory Tech is saying that if we just leave the button alone less heat will be ceated because even though the torque converter is locking and unlocking, the time that it's locked it's not creating heat. Am I close?

 

No, that's what the button was actually for, with the provisio that it's kind of annoying, but it's still what is bet overall for the transmission/converter under the programming Ford wrote for it. That's when I would say turn it off, but hardly any other time.

G

 

alright cool deal that makes sence