Ok so, after reading the manual and years of driving, I thought I knew what overdrive was meant for, but now I'm not so sure.

What are your recommendations regarding the use of O/D, and can I get a specific definition of what it's functional use is meant to be since the manual isn't clear on this?

Much appreciated!

 

Its simply 4th gear.

What do you want to know about it?

 

When and how do you use it?

Also: HOLY MOTHER OF ZEUS THAT WAS A FAST REPLY.

 

It is provided primarily to increase fuel economy. Generally you should leave it on except when having it on causes it to cycle in and out of overdrive repeatedly.

 

Overdrive is the highest gear in the transmission. We have 3 gears and overdrive (fourth gear). 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 you switch it on, you allow the transmission to shift into overdrive mode after the certain speed is reached. When it is off, the transmission shifting is limited to the 3 lower gears. For normal driving conditions, operation of the overdrive should be enabled.
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 3rd gear when more load is present. When less load is present, it shifts back to OD 4th gear. Under certain conditions like driving uphill or towing a trailer, the transmission may "hunt" between OD and 3rd 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, driving downhill.

 

You don't 'use' it. Just ignore it.
You can release it when coming down steep grades for some engine braking, but you don't have to. You can also release it if you are towing heavy, leaving you 'stuck' in third gear.

Overdrive ratio just means that the drive shaft turns more times than the crank shaft.
In the old days that was done with a small second two speed transmission on the back of the stock tranny.
Now it just means the top gear is geared 'higher' than top gears were geared in the past.

Chris

 

I turn mine off unless i'm going faster than 55

 

Just leave it alone. In those rare cases when you need the engine braking, then turn if off. Otherwise, like the poster above who turns it off below 55, you are doing nothing but wasting gas and turning more RPMs (read: more engine wear) than if you let the truck operate the way it was designed.

 

only time i turn mine off is when towing.. or going down a long grade.. (comming down from the mountains that way i dont have to ride the brakes)

 

I believe the booklet that came with my Troyer 93 octane tune, says you can do that very thing for increased throttle response. I certainly notice the difference with my 93 performance tune. If I am lead footing a bit I will turn it off to get the higher revs, and then turn it back on about 60mph to drop the rpm's back down. The 5.4 has the most kick in the 2-3000 RPM range....

 

when its 30 some degrees out and it takes forever for a truck to warm up you gotta do what you gotta do. besides I'm running royal purple whats an extra bump up a few hundred rpms gonna do

 

 

The transmission doesn't shift based upon load.

It is actually programed via the shift schedules which are throttle position and mph. (1-2, 2-3, 3-4, 2-1, 3-2, 4-3). The unlock schedules are a like as well.

 

I like your truck, what part of dallas are you in? i used to live in Rowlett. First lowered silver crew ive seen from these parts of the country.
-Patrick

 

Thanks man!.....I actually grew up in Rowlett over off 66/Dalrock, anyways Im in the Frisco area now....