I've noticed that my shift points are much better with O/D off. Is this normal or is there something funny with my truck?

For instance, accelerating onto the highway. When I'm getting up to speed with O/D on it will sit at 2,500rpms forever before shifting to 4th and/or O/D. With it off it shifts to 4th quiickly without hanging out at higher rpms forever.

Yeah that pretty much sums it up.

 

With overdrive off, if shouldn't shift into 4th at all...... TCC engagement perhaps?

 

Okay well third then. TCC? I'm a newb.

 

torque converter clutch. Instead of the normal fluid coupling you get from the t/c, it locks it solid, so you have a direct mechanical connection. Generates less heat in the fluid that way. Heat is what kills transmissions.

Mine likes to mess with me as far as the O/D shift though..... Sometimes, it will shift real nicely, like I think it should. Other times.... It seems to like to hang on to third gear for quite a while.... but, after the 3-4 shift, TCC engage happens shortly thereafter.

 

That kind of makes sense. It almost always skips 4th and goes right into O/D when I let off of the gas.

 

so you guys drive with the OD on constantlly then? O_o

 

This is my first Ram. Bought it this summer to pull my boat since our SUV couldn't do it. I thought it was normal for O/D to be on.

 

In and around town, OD off with my 98 2500 Ram. And what can kill these 46REs is towing with OD on.

 

I've never towed with it on. I know that's a no no. I was just curious about the craziness of the shift points between O/D on and O/D off.

 

here's my opinion and i may have some of this backwards because i haven't thought about it in a long time but - based on the transmission flash (old vs new), the OD off setting can allow or disallow TCC lockup.

In my old stock flash, OD on sucked bad, doing TCC lock at about 35, then shifting to OD at about 42 mph. rpm's stay low and it was a pig. with OD off, it would still do TCC lock, but not the OD shift. it drove a little better.

then along comes superchips, which reprograms the trans. it might be the latest dodge transmission flash, maybe?, i'm not sure. i can't find a tsb on it.
with OD on, it locks TCC at 40ish, then shifts to OD at 55ish. very nice.
with OD off, it doesn't lock TCC nor shift to OD, so it tows much better.