This is possibly a stupid question.....
When I bought my truck 5 months ago, the previous owner (a pretty knowledgable cummin's guy), told me to hit the overdrive button on the dash to turn off the overdrive up until about 55mph then to hit it again to turn the overdrive back on.

It was something to do with engine torque on the tranny at lower speeds..so best to keep the overdrive off until you hit the highway.

Now, my question is...what about the button on the dash? It gets a pretty good workout, and I dont imagine it will last a real long time with the high amount of usage...

Maybe I shouldnt worry about replacing this little switch in order to make the tranny live longer?

 

The switch should be pretty easy to replace...I don't know about leaving the truck in third until 55, though. It seems to me that 1.4-1.6K unlocked is better then 2K locked. Deff. less pedal and the lower RPM ftw.

 

I installed a relay that defaults the O/D to off whenever I start the truck. The instructions are here. http://www.dodgeram.org/tech/mods/tr..._inverter.html The switches are worth about $60 CAN if I remember correctly. The light in mine burnt out so I found a replacement bulb and soldered it in. The switch is easy to R & R.

 

I religiously unlock OD under 55 mph.
Perhaps that's why my stock tranny went 235K before I replaced it.
Never replaced my own switch but did a friend's.
Took about five minutes and cost $28

 

Am I assuming right that its more a factor of rpm's than speed when hitting OD? If I stay in it a little longer while accelerating on the highway it won't shift until 55-60 mph. Is this harmful to the tranny? Thanks

 

On the instructions is he saying ground 86 and 30? is it really this simple

 

Yup. All the O/D button does is give a momentary pulse to the PCM. With the relay, the pulse comes from the starter circuit. If your truck doesn't start the first time and you hit the starter again it will start with O/D on.

Bill,
28 bucks in the US for a button? Must be nice.