Odd 48RE tranny shift

ol Bombero-JC wrote:
Some bean counter had a fuel saving (bad) idea.....

2005 Dodge 48RE transmissions are the *only* year that has this *unique* feature:

Besides changing the shift points......
Pushing the tow/haul button on the 2005 Ram will lock out OD - *until* you press the accelerator - then it will shift back to OD (and remain in OD).

TWO things Tow/Haul on a 2005 does:
1. Changes shift points.
2. *Temporarily* locks out overdrive.

If you start (say from a dead stop) under load in TH, OD will stay locked out - *until* the computer decides (less load) it's time to shift into OD.
When that happens - it stays in OD - until you play the "button game" again.

Prior to the 2005 - pushing the TH button, locked out OD - until *YOU* canceled it.
Really just an OD "on/off" button.
For 2006, it changed to one push for Tow Haul, 2 pushes for OD lockout.
(or vice-versa).

Soooo - lots of strain on the Torque Converter for 2005s.
"Could be" (along with other things) the source of overheating.
Note: even the tranny folks say the '05 Trans cooler is way more than adequate.

I am re-considering the flash - as my 48RE went south at 80K miles.
(Original owner, not many towing miles, well taken care of, etc., etc)
Previously, I thought I would rather have the TH option - than true OD lockout.
Now I'm on the fence on that one!

BTW - BD (part #1031350) makes a converter to do the same thing as the 2006's for towing or running an exhaust brake.
About $200. - or if you're electrically talented, you can do the same on "the cheap" (the "mystery switch").

Google: BD Overdrive Lockout Switch for 2005 Dodge".
One of the retailers has the BD pdf on their site - which explains how it functions.

And - Spend some time on the various Dodge Diesel forums - you have to "filter out" the un-informed - regarding the "unique" 2005s.

Great source of *reliable* info on several of those forums is poster/moderator "cerberusiam".

Good luck..;)


~

My 05 does not temp lock OD out. TH changes the shift strategy and also allows the TC to lock in 3rd. The jump from 3rd to OD with the TC locked is big so it holds it in 3rd (TC locked) longer until around 55 MPH before it will let it shift. Once it's in OD it will hold it with the TC locked down to as low as 40.

I love the way my stock/factory 48RE works and I have been throwing high HP at it for years.