Transmission stuck in 1st gear

[VAram71]

2018 2500 with 6.4 66rfe 93,000k
Was driving from red light and when the truck went to grab 3rd gear, revs went up like it was put into neutral . Pulled over and truck went into 1st gear. Pulled out and would not shift out of 1st. Limped back to the house about 7 miles in 1st. Got to the driveway and put in reverse and it went into reverse a little harsh. Put into drive and would only go into 1st with a little throttle. About 1100 rpms. Shut truck off . Went out this morning put truck in reverse went in like normal put it in drive and took a couple of seconds later than usual and went into 1st. Heard slight ticking before it went into gear. Drove down the road shifted into 2nd then 3rd like normal drove that way for about a mile and a half.( Dirt road) Got on to paved road and came to stop. Started out in 1st into 2nd and before it could shift started slipping and it dropped back into 1st. Turned around and it shifted like normal back home. Was very easy on the throttle. Four days prior to this happening I replaced the plugs and coil packs with ruthenium NGK plugs and NGK coil packs. (Bosh iridium was from the factory)Truck ran fine for four days then tranny problems. Was going to do fluid/filter change a couple of days ago but got up in something else. Talked to a buddy of mine that is pretty familiar with these new Rams and he said to put the old coil packs back in before doing anything else. (The resistance from the new coil packs and plugs might be messing with the computers jiving) I'm old skool but I guess anything is possible with these damn computer controlled things. I was going to start with the fluid change and if that didn't fix it was going to go with pressure sensor transducer and speed sensors. Any tranny gurus on here have any thoughts?

 

[Wadejesu]

Doubt if coils have anything to do with trans, Best get a scan tool and if any codes show up.

 

[mtofell]

Yeah, extremely unlikely the coil packs and plugs have anything to do with it. My 66rfe failed twice before 100K miles and as these age there really are a lot of reports failures popping up here. The most common problem is the valve body but I believe that can lead to other issues. The slipping is definitely a concern. Have you looked at the fluid? Burned and black or still purple? All the weird shifting stuff is textbook valve body. As for codes, definitely check but for whatever reason the tranny failures don't trigger many. My first failure occurred with me sitting on the freeway basically just in traffic. Hit the gas to go and the tach just revved and the truck barely moved. I limped it to an exit with the tranny banging and slipping the whole way. I found a parking to to pull into but had lost all forward gears. Threw it into reverse and got off the road. Almost in comical fashion once I came to rest in a spot I got a CEL. Great... thanks. Yeah, I already had an idea there was an issue... LOL.

 

[RamDiver]

My only comment at this stage is why would you drive it period until further investigation?

If a transmission is compromised, park it and start troubleshooting or have it towed to a competent transmission shop.

.

 

[VAram71]

Yeah, extremely unlikely the coil packs and plugs have anything to do with it. My 66rfe failed twice before 100K miles and as these age there really are a lot of reports failures popping up here. The most common problem is the valve body but I believe that can lead to other issues. The slipping is definitely a concern. Have you looked at the fluid? Burned and black or still purple? All the weird shifting stuff is textbook valve body. As for codes, definitely check but for whatever reason the tranny failures don't trigger many. My first failure occurred with me sitting on the freeway basically just in traffic. Hit the gas to go and the tach just revved and the truck barely moved. I limped it to an exit with the tranny banging and slipping the whole way. I found a parking to to pull into but had lost all forward gears. Threw it into reverse and got off the road. Almost in comical fashion once I came to rest in a spot I got a CEL. Great... thanks. Yeah, I already had an idea there was an issue... LOL.

Fluid level was fine. Not burnt and still looks fresh even though it's never been changed . I was going to change it a couple of days prior but got caught up in something else. It's kinda weird that wouldn't even try to come out of first gear. I did get one code when I got close to home. P0 731 ( First gear ratio) . I think was do to me feathering the throttle trying to see if it would go in second. It slipped only once going from 2nd to 3rd and it went straight to first once it started slipping which it kinda does sound like something with the computers or like you mentioned maybe the valve body. Well tomorrow afternoon I'm going to mess with it and let y'all know something.

 

[mtofell]

Fluid level was fine. Not burnt and still looks fresh even though it's never been changed . I was going to change it a couple of days prior but got caught up in something else. It's kinda weird that wouldn't even try to come out of first gear. I did get one code when I got close to home. P0 731 ( First gear ratio) . I think was do to me feathering the throttle trying to see if it would go in second. It slipped only once going from 2nd to 3rd and it went straight to first once it started slipping which it kinda does sound like something with the computers or like you mentioned maybe the valve body. Well tomorrow afternoon I'm going to mess with it and let y'all know something.

The fluid not being burnt is encouraging. A valve body is a pretty straightforward swap with the tranny still on the truck. The rest of it gets pretty labor-intensive.

 

[WWlorodd1]

Same issue here but mine will drive fine if i use the manual shift option. I have replaced both the speed sensors and the only thing left to try is the shift solenoid inside the valve body. P0731 is the code I have. Any thought?

 

[Muddbugge]

I have the exact same issue did you get yours repaired what was the repair?

 

[WWlorodd1]

Not yet....just swapped the shift solenoid and same problem still. Next stop the shop...