48RE Tcc Solenoid

If your Ram will not lock the converter at highway speed, cruises with the tach a few hundred rpm higher than it used to, never grabs overdrive, or stalls the engine the moment you pull the lever into Drive, the part most owners end up searching for is the 48RE TCC solenoid. On the RE-family transmissions that solenoid does not come alone. Chrysler mounts the converter clutch solenoid and the overdrive solenoid side by side on one metal bracket, wired to a short harness that runs to the case connector, and that is exactly what this listing is: a new dual OD/TCC solenoid pack with its bracket, twisted-pair leads and plastic connector body, as shown in the photo.

What the TCC solenoid does in a 48RE

The 48RE still shifts first through third with governor pressure against throttle pressure, but the 3-4 shift and converter lockup are handed to two separate on/off solenoids on the valve body, which ATSG describes in its RE-series service information. When the PCM grounds the TCC solenoid, oil is sent to the converter clutch control valves and the lockup clutch applies. The 48RE changed where that oil comes from. Transmission Digest's Wayne Colonna explains that the 48RE TCC solenoid is fed forward-clutch pressure instead of second-gear oil from the 1-2 shift valve, and Sonnax adds that the feed now comes from the manual valve in any Drive position, which lets the truck lock up in manual 2 and manual 1 for towing at low engine speed. The pressure regulator also raises line pressure roughly 22-28 psi when lockup or overdrive applies, against about 10-15 psi on a 46RE or 47RE, so the converter clutch gets more clamping force.

Symptoms of a failed OD/TCC solenoid

• No converter lockup at cruise, higher rpm and worse fuel mileage, especially loaded or towing.
• A lockup shudder or cycling in and out of lockup between about 40 and 60 mph.
• No fourth gear, because the overdrive half of the same pack has failed or lost its ground.
• Engine stall as soon as Drive is selected but not in Reverse. On a 48RE a restricted TCC solenoid can apply the converter clutch the instant forward-clutch oil arrives.
• A stored P0740 or P1740, which Transmission Digest lists among the recurring lockup codes on RE units.

How to confirm it is the solenoid

Rule out the rest of the lockup circuit before you buy. A stall in both Drive and Reverse points at the pump or a restricted cooler, not the solenoid, and Colonna notes that a bad pump and a bad TCC solenoid can exist together, which is why some trucks still stall in Drive after a new pump. Check the coil resistance and the ground from the PCM at the case connector, and make sure the transmission control relay is powering the solenoids with the engine running. If the solenoid tests good but lockup still slips or shudders, the problem is likely worn TCC apply, lockup boost or switch valve bores in the valve body; Sonnax's 48RE vacuum test guide lists TCC slip under load, TCC cycling and no lockup as wear symptoms at those valves. Our 48RE shift solenoid guide has the full test sequence, and the 48RE pump failure guide covers the stall-in-Reverse side.

Fitment

This is the RE-family dual solenoid pack listed for the 48RE, the four-speed behind the 5.9L Cummins in 2003-2007 Ram 2500 and 3500 trucks. The same solenoid arrangement runs through the 42RE, 44RE, 46RE and 47RE, but the bracket, lead length and connector body were not identical across every year. Compare the bracket holes and the connector shape in the photo with the unit on your valve body, or send us your year and VIN and we will confirm before it ships. Every part we stock for this transmission is on the 48RE parts page.

Install notes

• Drop the pan, remove the filter and valve body, and transfer the pack carefully; the leads are thin and chafe easily on the transfer plate.
• Use new O-rings on the case connector so it does not seep fluid into the plug.
• Refill with Mopar ATF+4. Chrysler lists the 48RE service fill at about 8 pints with a pan drop; check level hot in Neutral at idle.
• Road test through several lockup cycles in third and fourth before you call it done.

If the governor side is acting up too, the 1994-1999 RE solenoid kit covers early trucks, and late trucks with worn bores are better served by a 2005-2007 48RE valve body.

Is this just the TCC solenoid or both solenoids?

It is the full pack: the TCC solenoid and the overdrive solenoid on one bracket with their harness and connector body, the way Chrysler built it. The two are not sold separately on RE-family transmissions.

Why does my 48RE stall in Drive but not in Reverse?

On a 48RE the TCC solenoid is fed forward-clutch oil, so a solenoid stuck applied can lock the converter as soon as Drive is selected. A stall in both ranges points to the pump or a restricted cooler instead.

Will a new solenoid fix a lockup shudder?

Only if the solenoid is the cause. Shudder that remains with a good solenoid and fresh ATF+4 usually comes from worn lockup valves in the valve body or a worn converter clutch.

Will it fit my 2003-2007 Ram 2500 or 3500?

It is listed for the 48RE in those trucks. Match the bracket and connector shape to your old pack, or send us your year and VIN and we will confirm before it ships.

What fluid should I use after replacing it?

Mopar ATF+4. Chrysler warns that a non-specified fluid can cause poor shift quality and converter shudder on these trucks.

• 48RE Shift Solenoid Symptoms: Overdrive and TCC Solenoid Testing and Replacement
• 48RE Pump Failure Symptoms and Replacement
• 48RE Cummins Transmission Problems: Failure Points, Upgrades, and What Actually Breaks
• 48RE Ram 2500 Cummins Shift Problems: Diagnosis and Fix