Hi!

I'm a new Dodge owner, with a question for all ye wise mopar sages:

I bought my Durango almost two months ago, and I love it! the PO is a friend of mine and serious mopar nut (and is an engineer by trade), and he told me to always turn the O/D off for regular city driving, or risk premature failure of the tranny (46RE according to the build sheet). Now, I know the O/D should be off for towing (which I will rarely do), but it just doesn't make sense to me for it to be disabled for normal driving. Can anyone shed some light on this for me?

Thanks!!

BTW - this site is great! Helped me solve my ABS/Brake light issue!

 

It does say in the owners manual to turn the O/D off in towns, pulling trailers or going through hilly sections of roads. Usually if you're going 40 MPH and below you can turn the O/D off that way there is less slip in the torque converter.

 

Thanks Monster,

That clarifies things a little. It still seems strange to me that Dodge would automatically enable a feature which should normally be turned off.

Since almost 100% of my driving falls into the categories you mentioned, I wonder if there's a way to default the O/D off at engine start? I'm getting tired of pushing the little button every time I start the engine...

From what I've read about these transmissions, they're based on a Mercedes design. If that's true, how do they get away with using O/D?

 

it may be recomended but i dont think that dodge would have overdrive turned on by default if it would dammage it. with overdrive off the engine rpms run pretty high...

 

What it does is lock up the torque converter so there is no slip. During stop and go traffic, towing, and hill driving this adds heat from slight slippage due to torque management. So during these conditions you should lock out of OD (this locks the torque converter) so there is no slip and thus this saves life on the transmission not to mention alleviate unnecessary shifts that cause even more heat.

Torque management offers 2 advantages,

1. A faster 0-60 because it keeps the engine in power band longer helping you gain more "in the pants" feeling and increasing off the line TQ and HP numbers in the power curve.

2. Helps make the transmission shifts nice and easy so it doens't have a "slam" feeling so the potential buyer doesn't think it has a bad transmission. This is a simple commodity. The larger part of this shifting is the time between shifts. They increase this time to also aid in a softer shift, but this creates a lot of unneeded ware.


This is why shift kits are good for transmissions, it makes the gear switch faster and good engagement so there is no heat generated and the bands stay thicker and last longer because there is no slip during gear changing and stays in gear without unneeded shifts.

So your friend was right. It will save you more fuel and less ware.

 

hydra where do you get these shift kits? what are they called...

 

Wow! Thanks for the very thorough explanation, Hydra! O/D off it is...

I think I see a shift kit somewhere in my future.

 

I've always just put it in drive and went, I never knew it made a difference in certain situations. I'll have to try this and see what happens.

 

Removed

 

so O/D is always on? I've never touched my O/D button since I bought my truck in '03 so does that mean it's been on all this time?