1996 2500 OverDrive button Function
Professional
Joined: Feb 2009
Posts: 155
Likes: 0
From: Trevor, WI
Yeah, you can think of the O/D as the 2nd gen's version of "tow/haul mode" so when your towing or hauling something heavy, then turn the sucker off. that's really all there is to it. The hill thing, I understand turning it off, just to prevent it from shifting in and out of O/D so much, and getting hot. But those are really the only two basic rules you need to know about that. Read up on it in your owner's manual for some good info too.
Administrator
Joined: Apr 2010
Posts: 87,380
Likes: 4,210
From: Clayton MI
On the 96, the PCM MIGHT monitor the trans temp, but, if it does anything different when it is overheating, I sure haven't noticed..... (aside from it driving REALLY funny, and smelling terrible......) Temp gauge monitors engine coolant temp, trans has nothing to do with it. (aside from contributing a bit of heat from the in-radiator trans cooler)
If you do a lot of towing, a dedicated trans temp gauge is darn near a requirement.
If you do a lot of towing, a dedicated trans temp gauge is darn near a requirement.
Moderate User
Joined: Oct 2008
Posts: 17,003
Likes: 21
From: Albany, NY
My concern: The transmission doesn't know or care what's driving it. Running along in overdrive, the pump RPM is lower than it would be in normal drive, so the line pressures are lower, too, which means less clamping force on the clutches. Dropping it back into normal drive brings the line pressures up, increasing the clamping force applied to the clutches.
But, as always, live like you want to live.
But, as always, live like you want to live.
If you had a gas truck with 800hp you would still need to disengage O/D when towing heavy loads around unless you are on a completely flat surface such as a highway with no headwind.