O/D on or off?

[Andy96XLT]

I'm gonna go do some research, i'll let everyone know what I find, I hope I haven't been destroying somethign by takeing my car out of O/D to go up this hill

 

[Willard]

No, you haven't. That's what I've been trying to say. That's part of the reason you can take it out of OD, for hills. Read the manual, it talks about taking it out of OD for hilly terrain, and explains other times to use it.

 

[Dylansav]

I'm not gonna touch that OD off button unless I got a trailer behind me..even though it makes me feel cool..

 

[Andy96XLT]

devilboy, im with you, its what my dad always told me to do and I just found this:

Usage:
Generally speaking, overdrive (OD) is the highest gear in the transmission. Most automatic transmissions have three speeds and overdrive (fourth speed). Overdrive allows the engine to operate at a lower rpm for a given road speed. This allows the vehicle to realize better fuel efficiency, and often quieter operation on the highway. When it is switched on, the transmission can shift into overdrive mode after a certain speed is reached (usually 70+ km/h [45+ mph] depending on the load). When it is off, the transmission shifting is limited to the lower gears. For normal driving conditions, operation of the overdrive should be enabled only if the average speed is above 70 km/h (approx. 43 MPH).

It may be necessary to switch it off if the vehicle is being operated in a mountainous area.

The automatic transmission automatically shifts from OD to third gear when more load is present. When less load is present, it shifts back to OD. Under certain conditions, for example driving uphill or towing a trailer, the transmission may "hunt" between OD and the third gear, shifting back and forth. In this case, switching it off can help the transmission to 'decide'. It may also be advantageous to switch it off if engine braking is desired, for example when driving downhill. The vehicle's owner's manual will often contain information and suitable procedures regarding such situations, for each given vehicle.

It is definately OK to take it out when you need more power. I don't know why everyone else says not to do it?

 

[Gatorblazer]

I agree with Al.

You disengage OD when towing because you dont want the tranny shifting in and out of OD constantly. Constant on and off shifting (meaning every 30 seconds or so) when towing will create excess heat in the tranny, and lots of heat is never good in any mechanical part. Overdrive is always engaged when you crank your truck. Hitting the button on the shift stalk simply turns off the OD, preventing you from shifting into it. You cannot create more torque by turning OD off in all gears. Torque (energy) is not "created" by the tranny, it is transfered from engine RPMS through the tranny by a little thing called a "torque converter".

 

[Willard]

I don't know why somebody would say not to use it either. Theoretically you wouldn't hurt anything if you never used it, you would just be running higher RPM's and sucking more fuel.

That's a good explanation of OD. Should clear up some stuff.

Edit: Just for clarification, there is no reason to turn it off MOST of the time. Only when needing more power at high speeds, as such when towing or driving up large hills.

 

[Dylansav]

I like that a lot andy, that's really good to know.

 

[BIGHVM]

I tend to leave o/d on except when facing a big hill, then I will turn it off for the climb to prevent revs droping and down changing too often- thats I think the correct way to us it, I do not tow anything to listen to the guys that have if you plan to do that mate!

 

[MadExplorer93]

I drive my 1993 ex with the lever in OD all day long. The only time you should be out of OD is if your towing a trailer, well a camping trailer or a heavy load, but i have a very small utility trailer and i use OD for it as i am lucky if i can get 200-300 pounds of weight in it.

 

[Buffalosports]

Confused? Indeed. Read a little more about OD.

Don't need to at all. I, for one, know what O/D is. Good luck running your Ex at 100 miles an hour in 3rd gear.

 

[Buffalosports]

It is definately OK to take it out when you need more power. I don't know why everyone else says not to do it?

Not at 70 miles an hour. As you said it switches at approx. 43 mph. If you are doing 70 miles an hour in 2nd or 3rd gear, your RPMs are way to high and it puts tremendous amounts of stress on the engine.

 

[MadExplorer93]

Yes i agree around 80KM per hour the OD gear shifts in and the OD is for better fuel economy on the highway when driving with out a trailer. If your towing a camping trailer or a trailer with a Boat on it, i would not use OD feature as you need the Power To pull now and that is what the BIG D beside the OD in the selector is for or in some models 3,2,1 is the options and 3, is what you would then for pulling/towing.


Some newer models have a selection for OD which is a Button style, kinda like our Auto 4x4 selection is.

Also Never, Never, Never take it out of OD when doing any speed that is over 20KM, actually stop before you do it.

 

[Willard]

Don't need to at all. I, for one, know what O/D is. Good luck running your Ex at 100 miles an hour in 3rd gear.

I only mentioned 100 miles an hour in third because it was possible. I know people here have done it seeing what speed they could reach. You couldn't do this in OD, it couldn't handle the stress.

 

[Buffalosports]

I only mentioned 100 miles an hour in third because it was possible. I know people here have done it seeing what speed they could reach. You couldn't do this in OD, it couldn't handle the stress.

My point exsactly. That would be the point of O/D. That was what I was TRYING to say. I think we are basically saying the same thing.

 

[MadExplorer93]

So guys/girls drive in OD for normal daily driving and use 3, gear or the BIG D for towing, but remember when towing don't exceed 80-90KM per hour.

 

[Dylansav]

You Both are right

 

[Dylansav]

So guys/girls drive in OD for normal daily driving and use 3, gear or the BIG D for towing, but remember when towing don't exceed 80-90KM per hour.

That's a good cap on this, thanks for all the help on this thread everyone!

 

[aldive]

Don't need to at all. I, for one, know what O/D is. Good luck running your Ex at 100 miles an hour in 3rd gear.

Say what? I don't run my truck at 100 MPH in any gear.

 

[Willard]

Say what? I don't run my truck at 100 MPH in any gear.

I think he was talking to me, since I mentioned it, it just sounds like he was talking to you...

 

[Andy96XLT]

all i know is it is perfectly safe to turn off o/d at 70 to go up an incline for a short amount of time. My research along with my mechanic told me this as i had to talk to him today about my dads car so i just figured i would ask lol

ps my rpms are barely hitting 3000 in 3rd gear at 70