In a previous Transmissions Digest article, a master mechanic examines some of the hydraulic features of the Dodge 48RE. Many owners have found the valve body hydraulics to be a bit of a mystery, especially since it looks very similar to the 46/47RE. Some have even gone to the extent of installing a 48RE transmission in a 46/47RE valve body, which seems like a genius idea until a few miles later when you need to replace the damaged overdrive clutch and torque converter.
The two valve bodies are different
When you fit the 48RE into a 46/47RE, you can definitely expect some damage - irreparable in some cases. There are two reasons for this:
- First, the two differ in the pressure curve related to the pressure regulator valve due to subtle changes in the valve body
- And second, the torque converter clutch (TCC) solenoid feed circuits, as well as the hydraulics for the torque converter clutch control valves are different
Evolution of Dodge Transmissions
The pressure regulator valve is placed differently when compared to other pressure regulator assemblies in the TorqueFlite family of transmissions. The pressure regulator valve has multiple reduction points applied to the different valve spools of the valve that force the valve in a position so as to reduce line pressure. An increase in throttle causes the throttle pressure plug to move in the opposite direction, so the spring can move the pressure regulator into a position to enable pressure increase.
Production of the 46RE started in 1996, around the same time when higher torque gas and diesel engines came into production. So, Dodge incorporated a new valve train adjacent to the pressure regulator valve to help boost pressure when in 4th gear or lockup. This allowed the pressure regulator to increase line pressure by around 10-15 psi to help boost clamping power for the overdrive clutch and torque converter.
Production of the 48RE started in 2003, and a number of changes were made to the gear train and clutch packs that made the transmission different from its 46/47RE predecessors. Subtle changes were also made in the valve body to boost the pressure curve, resulting in considerable increase in the TCC clamping force. This is necessary for heavy-duty applications such as towing.
There was also a change in the hydraulics for the TCC control and the torque converter solenoid feed circuit.
In summary, many small and subtle changes were made to the 48RE that gave it considerable clamping force and a pressure curve that is different to the 46/47 valve body, essentially making the two distinct from each other. You can find out more details about the Dodge 48RE hydraulics features by visiting this link http://www.mirabelsmagazinecentral.com/digitaledition/index.html?id=f037f159-9518-4196-ac92-8b3aec4cc24c from page 18 to 26.
If you believe that your transmission problems are affecting the performance of your vehicle, contact Pro-Tech Transmissions for professional diagnosis and repairs.
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