I just got a new truck to me and am trying to adjust to the auto tranny. Some have said not to run in OD if just driving around town and under 50 mph. I notice that with OD off my truck only drives in 3rd gear and doesn't shift into 4th. I think anyway. If I turn OD back on it shifts into 4th and then I think I feel OD kick in. Can you guys give me the shift patterns of your auto tranny? I want to know how others are shifting and at what speeds. Just trying to make sure that there is nothin out of the ordinary. Thanks...

 

4th = Overdrive.

With O/D disabled, the computer will normally let the torque converter lock-up in 3rd.

So, with the gear selector in D and O/D enabled, it will go:

1st -> 2nd -> 3rd -> O/D (4th) -> TC Lockup.

With the gear selector in D and O/D disabled, it will normally go:

1st -> 2nd -> 3rd -> TC Lockup.

With the gear selector in 2, it goes:

1st -> 2nd.

With these trucks and a stock trans, most of the shifts will only show a very minor RPM change. When the converter locks while in O/D though, you'll see a much bigger RPM drop. The computer normally locks up the converter at ~50mph in O/D. It can vary in 3rd depending on load.

 

this tranny is made to live in conditions about 800-1000rpm higher....u will notice that after getting governor springs your rpms will drop nicely between shifts and the shifts will be really hard...and you'll barely feel the tc lockup but in stock mode the "extra shift" that u think ur feeling is the TC lockup

i noticed that in the higher rpm ranges this tranny is a beast....must be a nice tranny behind the V10 but it takes a beating in with the cummins especially a 1500rpm peak torque setup(12 valve)

 

What you may notice that seems odd is that in going from OD off to on that the tranny shifts three times.
It goes 3rd tc locked> 3rd> 4th> 4th locked

 

Thanks for the replies. Sounds like it is shifting normally. I do want to put some governer springs on soon and see what it shifts like. 3k I think. So what do you think about keeping OD off if under 50 mph? Is it necessary? Is there a mod to have the truck start with OD off instead of on?

 

yes there is a mod like that overdrive inverter switch if i recall...can get the instructions at dodgeram.org...in the modifications section i believe

i drive with the overdrive locked out all the time unless on the highway

 

yeah, the mod is a simple relay. While cranking, the relay closes and sends a ground momentarily to the pcm disabling OD. Don't need an expensive kit for this mod....just a relay and a pin-out to tap the right pcm wire.

 

OD switch mod described in detail here
http://dodgeram.org/tech/mods/transm..._inverter.html