I was searching for an answer to this question a while back and asked a question on someone else's thread. I didn't want to resurrect an old thread so I thought I would repost my issue here, update you on what happened, and is happening again.
Here is my original post:
I have a 2018 Ram 2500 w/ 6.7L Cummins and the RFE68 6 speed transmission. In February 2021 at about 50K miles I started to experience a very harsh downshift from 5th to 4th. I should also state that almost 100% of the time I am in Tow/Haul mode and use the Full-time Exhaust Brake feature. In town I also limit the transmission to a max of 4th gear so I don't lug the motor. It keeps it in a higher torque range and it drives much smoother. On the freeway I limit the transmission to 5th gear while I'm towing which is 95% of the time I'm using the truck. After it happened a few times I confirmed the issue by using the Driver Selectable Gear mode and limiting the truck to 4th gear. While decelerating it downshifted smoothly through the whole range 4-3-2-1. Then I used the DSG mode to allow the transmission to shift into 5th gear. During deceleration the transmission downshifted very harshly from 5-4 and then downshifted smoothly from 4-3-2-1. I repeated the testing using just the Tow/Haul Mode, just the Exhaust Brake Mode, and again with both the TH mode and the EB Mode engaged.
The transmission downshifted harshly from 5-4 in all modes but did so more harshly while using the combination of the TH and EB Mode. I took the truck in to the dealer for service and the tech confirmed the issue. They refreshed the computer and went through a relearn mode. The truck was under warranty but they charged me for the update saying it wasn't covered under. I balked at that but lost the battle. The transmission was fine for about 5 months and in until August 2021 at about 80K miles the issue came back. I made an appointment and took the truck in. They called and said the tech was not able to confirm my issue and asked me to come in. I took a different tech (the previous tech already went home) out for a test drive and on the first downshift the problem was confirmed. We went back to the shop and the Service Manager said they couldn't work on my truck since the transmission guy went home. (That was the tech that couldn't confirm my issue) and it might be a day or two until they could get to it. That didn't work for me since I use the truck for my job. I made a new appointment and said that was the day they could work on it.
I took the truck in for its new appointment and it still took them two days to service it. WTF?!!! They corrected the issue with another refresh and test drive. I told them I wasn't paying for the same thing to be done since they just did it. This time I didn't pay for the service. The transmission was working fine until last week, which was two weeks after they fixed it, and now it is doing the same thing.
Has anyone else had this issue and what do you guys think it might be and what is my recourse for getting it permanently fixed?
So several months back I had the valve body replaced by the dealer with help from FCA. The technician agreed with me that the hard downshift was a result of the valve body not holding proper pressures which allowed the transmission to shift poorly. The valve body was replaced with about 85K miles on the clock. The new valve body did the trick and the truck has been shifting great.......................until yesterday. The problem has started all over and in the exact some way. I now have 110K miles on the clock so the transmission is no longer under warranty. However, I do intend to contact FCA and complain about the fact that the brand new valve body has only lasted 25K miles which by anyone's standard is a pretty poor quality part. This seems to be about how long they last though. As I've learned through my research the valve body pistons on the 68RFE from Ram are poorly designed, lack tight tolerances, and wear out very quickly and the aftermarket companies are using piston cit from billet aluminum. Not sure if that is marketing hype or truth. But I can see why that would cause them to fail.
If FCA doesn't agree to cover the part I'm considering an aftermarket valve body by companies such as ATS Diesel, Diesel Power Products, Suncoast Diesel, or any other specialty aftermarket diesel transmission companies. Has anyone here had a similar issue and repaired it with an aftermarket transmission from some other company? If so, how was your experience and did it finally correct the issue?
