Keep Those Trannys Rolling - July - 2020

66RFE, Are Your Plugs in Place?

In this issue of Keep Those Trannys Rolling, we’re going to take a look at a 2013 Dodge/Ram R2500 that was towed into the shop with a “no move” condition.

Our 2013 Dodge/Ram R2500 is equipped with a 5.7L engine and a 66RFE transmission. According to the customer, he had taken his vehicle to a local automotive repair shop to diagnose a delayed engagement and an erratic shift concern. The customer said the vehicle had been in the shop for a couple of weeks, and the repair shop was unable to repair the transmission. The customer went on to say that the repair shop had replaced the valve body assembly with a valve body from their local Dodge dealership, and ever since then, the vehicle would not move. The customer added that the repair shop had removed the transmission so they could disassemble it to look for an internal problem. That’s when the customer decided he had better get a second opinion.

Initial Inspection:

As always, the first step to performing any diagnostic procedure or repair is to perform an initial inspection of the vehicle. When the vehicle arrived at the shop, the transmission had been removed and placed in the back of the bed of the truck along with the torque converter. They continued the initial inspection, checking under the vehicle and under the hood for possible concerns.

Transmission Inspection:

The transmission assembly was placed on the bench, and the pan removed. There was fine metal debris and clutch material in the pan. It was pretty obvious that this transmission had an internal problem. After the transmission was disassembled, there were several clutches slightly burnt, but not enough to keep the vehicle from moving.

The source of the fine metal debris was believed to be coming from the torque converter. An air check to each component at low pressure with 35 psi of regulated air pressure verified that the clutch circuits were intact and had no leaks. Each clutch component air checked at low pressure.

Transmission Repair:

The transmission was thoroughly cleaned and inspected during the rebuild procedure. All of the clutches, pistons, sealing rings, and needed components were replaced. The transmission was assembled, and air checked again to verify proper clutch operation.

Valve Body Concern:

Knowing that the previous automotive repair shop had replaced the valve body with a rebuilt valve body from their local dealership, we could probably assume that the rebuilt valve body was not the problem. But wait a second, during our initial conversation with the customer, the customer had indicated that the transmission seemed to work okay, except for a delayed engage and erratic shift at times, before the repair shop installed the valve body. According to the customer, that’s when it developed a “no move” condition. When the valve body was inspected, it became very obvious what was causing the issue. The valve body was missing the clutch pressure port plugs that seal off each clutch passage (Figure 1). It’s not uncommon to pull a new part out of the box and never think twice about whether it was assembled correctly or not. What you may not know is that Dodge does not install the clutch pressure port plugs onto their valve bodies and recommends transferring the pressure port plugs from the original valve body to the replacement valve body.

To repair the issue, they found a set of pressure port plugs from a used valve body they had in the core bin and installed them into the rebuilt valve body’s clutch pressure ports (Figure 2).

Back in the Vehicle:

Once the transmission was back into the vehicle and filled with fluid, the shifter was moved through each of the ranges and allowed the transmission to engage into each range. Confidence was high that the transmission was going to work. The PCM was checked and cleared of all codes and reset before the test drive.

Test Drive:

The transmission shifted, but the shifts were a little mushy. This is to be expected as the adaptations are resetting. As we continued to drive through town, the shifts started getting better. The transmission downshifted and upshifted as expected during freeway speeds.

Final Inspection:

During the final inspection, the underside of the vehicle was checked for leaks, and none were found. All fluid levels were checked and verified full. Well, there you have it. With a little bit of knowledge and six clutch pressure port plugs, you should have no problem “Keeping Those Trannys Rolling” down the road.


(Special thanks to Mark Pourciau and Billy Brinegar at Budget Transmissions in Baton Rouge, LA for their contribution to the vehicle repair process and storyline)