First time truck owner(2nd car ever). What is the overdrive for? What does it do???

 

Turn it off. Get on the freeway. Turn it back on.

If you still have questions...
http://en.wikipedia.org/wiki/Overdrive_%28mechanics%29

 

Is it just used for cruisong on highway to save gas

 

FOLLOW THE LINK. Read the information. Don't ask any more questions until you do.

 

You are correct, it lowers your engine rpms when you are cruising and not needing alot of power. With it off your engine will rev higher and use more fuel. If you are towing heavy loads through hilly terrian you can turn it off so the transmission doesn't keep going in and out of overdrive, this is bad for the transmission. Also this will keep your engine in it's powerband so you have enough torque to pull the load. But remember to turn the O.D. back on when you get to flatter ground.

 

Hey don't let these guys give you crap about not knowing everything there is to know about trucks. Everybody has to start somewhere. Welcome to truck ownership, and the site. Nice Truck BTW.--DIY

 

DIY-thankyou-

 

Just think of it as your 4th gear.

When the button is "on" it allows the tranny to shift into "4th" gear (overdrive).

When the butotn is "off" it will not allow the tranny to shift past third gear.

Pressing it while on the highway will downshift fromt "4th" (overdrive) to third.

 

It is the magical mystical gear that lets you get 1000miles per gallon towing a billion pounds.

heh heh

Simply a gear where the output of the tranny is faster than the input. This advanage comes at a price of power. You can't really accelerate in it.

Here are your 4R70w's ratios

1st 2.84:1
2nd 1.55:1
3rd 1.00:1
4th 0.70:1
Reverse 2.32:1

Adrianspeeder

 

Who gave him crap? I directed him to a site that will give him some excellent information about overdrives and how they work - a lot more information than anyone has given him here. Reading is the place to start. I think it is great that he is asking questions and wants to know more.

Fordwitflows - keep asking those questions - that is how you are going to learn.

 

can you turn o/d on and off at any time or should you let off the gas or anything like that before you do?

 

You can do it at anytime, moving or not, any throttle position.

 

alright thanks cause I pulled an enclosed trailer full of fourwheelers to nashville and back this past weekend and I was wondering that.