6.7L Cummins Forum

The Orion 68RFE automatic transmissions is a sophisticated, multi-range, electronically controlled transmission which combines optimized gear ratios for responsive performance, state of the art efficiency features and low NVH. Other features include driver adaptive shifting and three planetary gear sets to provide wide ratio capability with precise ratio steps for optimum driveability.
The hydraulic portion of the transmission consists of the transmission fluid, fluid passages, hydraulic valves, and various line pressure control components.
The primary mechanical components of the transmission consist of the following:

• Larger bell housing with a different bolt pattern and a cutout to accommodate diesel applications.
• Three multiple disc input clutches
• Three multiple disc holding clutches
• Five hydraulic accumulators
• Three planetary gear sets
• Dual Stage Hydraulic oil pump
• Valve body
• Solenoid pack

The Transmission Control Module (TCM) is the “heart” or “brain” of the electronic control system and relies on information from various direct and indirect inputs (sensors, switches, etc.) to determine driver demand and vehicle operating conditions. Depending on the vehicle configuration, the TCM may be a standalone module or it may be housed along with the Powertrain Control Module (PCM) in a single module. With this information, the TCM can calculate and perform timely and quality shifts through various output or control devices (solenoid pack, transmission control relay, etc.).
TRANSMISSION IDENTIFICATION



Transmission identification numbers are stamped (1) on the left side of the case just above the oil pan sealing surface. Refer to this information when ordering replacement parts. A label is attached to the transmission case above the stamped numbers. The label gives additional information which may also be necessary for identification purposes.

GEAR RATIOS

The 68RFE gear ratios are:
1st 3.23:1
2nd 1.83:1
3rd 1.41:1
4th 1.00:1
5th 0.81:1
6th 0.62:1
Reverse 4.44:1

__________________

2007.5 Dodge Ram 3500 HD,QC, 6.7L Cummins, 6speed Auto, 4X4, Bighorn Edition.
Click for installs: Carr Steps PML Diff Cover Edge Juice with Attitude Volant Intake Hankook ATM RF10

One of the things I really like about the 68rfe is the low gear in reverse. There is no straining when trying to back up the RV up a steep grade to place the RV on a camping site. At our favority camping spot in the Blue Ridge mountains I have to manuver the rig up a very steep incline and I can do it at an idle.

__________________
CUMMINZ NC
2007.5 CTD, QC-DRW 3500 BFT Laramie, Smarty S-67, AMSOil Dual-Gard Bypass, Custom Line-X 4x4, 4.10LS, 988s, 68rfe, MBRP 5", Mobil Delvac. Yukon free spin, 19.5x245 G647 Goodyear's - 2006 - 37RLTSD Cedar Creek-Day Dreamer
My 2007.5 DRW Truck at www.CumminZ.com

Does anyone know where the TCM module is located on a 07 3500 mega cab. Or is it integrated into the pcm?

On the firewall in the engine compartment on the passenger side.

This outfit is offering a TCM tune to increase performance and durablity of our auto trannies.

Modern Horsepower offers performance tuning, driveline tuning, and performance parts; including exhaust systems.

__________________
2007 2500 MegaCab 6.7l Auto 3.73 Edge Juice with Attitude, MHP TCM tune, Nitto Terra Grappler 285 70 17, AFE Stage 2 Pro Dry CAI, XRT and repaired NOX and DPF, more good parts on the way)

My home is for sale www.digphoto.net/home

My trans is sticking in 4th gear. Anyone else having troubles. 2008 3500 AT with 55500 miles. Getting code p1776 .

Did you take her in and what did they find out?

__________________

2007.5 Dodge Ram 3500 HD,QC, 6.7L Cummins, 6speed Auto, 4X4, Bighorn Edition.
Click for installs: Carr Steps PML Diff Cover Edge Juice with Attitude Volant Intake Hankook ATM RF10

I have noticed that my truck quickly gets to 5th gear; even from a complete stop. However, it doesn't downshift as quickly as it upshifts. While driving from a flat plane to an incline the transmission does not shift down to a more efficient gear; causing a grinding type noise. It doesn't sound too serious, but I think it would be much better on the transmission to be in 4th gear. Typically, I use my thumb shifter to downshift.

As a side, I believe a more responsive transmission would conserve fuel. It is for this reason, I'm considering a programmer that has programmable shift points.

Has anyone else noticed about their transmission?

I didn't like the way my tranny shifts, looked for a shift kit to install but nothing avalible right now. But found Welcome to B&G Performance "A World Leader in DCX & EURO Tuning Solutions" - Dodge/Jeep/Mini/Bentley Motors/AMG/Mercedes/Ferrari/Porsche PCM/TCM(Computer)Flashes and ordered a tcm computer and it is a night and day difference shifts are harder and power band comes in strong.