Sharpsshooter, I was referring to the shift points from 1-2 and 2-3. O/D is controlled by the computer, as well as the torque converter lockup, you are right, so that can be controlled. O/D was never in question, as this thread is about turning it off, just the rest of the shift points were what we were discussing.

 

Whoa! look out mr. owners manual! LOL!

 

Got it. We were saying the same thing, just approaching the question from different directions. O/D sure changes the complexion of the tranny. I am looking at the O/D Switch Inverter mod due to the fact that I like the idea of having it off by default.

In the flesh! Seriously though, it is a pretty decent manual. I learned quite a few things from it. Good source for info.

 

That it is.

 

As stated before, I think it's the engaging and disengaging of overdrive that causes any of the issues. That is what I can't stand about slow driving people who don't follow the speed limit. I'll finally get my truck into overdrive and I'll be cruising around 55mph down the back roads, then some dick *** will either pull out in front of me or some bitch won't move and my truck will kick out of overdrive and I'm stuck going into overdrive and then going out of overdrive. Finally I'll just get so pissed off and pass the ****er, but then I'll feel bad that I just slammed the **** out of my truck. Pain in the ***.

 

I'm pretty sure it does... Maybe it's not extreme engine braking... but it definitely slows you down faster.

For example, if I'm going 45mph and let off the gas, I will coast much further if OD is engaged.

With OD off... that tach stays higher... and you can feel the truck slow down much faster. As soon as your foot comes off the gas, you instantly sense the slowing of the vehicle.

With OD on... when I pull my foot off the gas, the tach will drop to about 1000 or so, and stay there. I don't notice the vehicle starting to slow... it just kinda keeps going. As you get get closer to fully stopped the tach will drop down to about 6/700 RPMs.

With my drive to work... I appear to get better mileage with OD on even with the speeds below 45mph the whole time. I do a lot of "coasting" up to red lights - and OD seems to help in that aspect...



Cartman

 

I get the same mpg's as you, and the only "mod" I have is 285 tires on the stock rims.

 

ive got 1997 1500 with the 318 and I have to baby it to get 10 mpg what octane to you use? The whole truck is stock except for the exhaust Flow master super 40

 

OK, so I was wrong about the heat when in OD .So it's lasted this long because I never beat on it and it hardly ever has a load in the bed and I don't tow anything(plus it's maintained very well). But I can't stand the bogging when the TC locks up or when it goes into OD (so I turn it off). TC lock up mainly is what I hate. At least I have control of OD! So I know it's mostly because of the 3:55 gears, but money wise there is nothing I can do about that right now.

 

I was getting the same milage with my 97 1500 and it also has a 318 I found it had the intake plentum pan gaskit blown out and I also had a junk set of Champion plugs took them out and put in a set of NGK plugs got it up to 14.5mpg