2018 6.4 Trans issue/question

[Jughed]

2018 Ram 2500 6.4 6 speed, 41k miles. Not a hint of trouble to date.

No codes/alarms/CEL

Truck has not towed anything in 3 months, problem is acute - didn’t happen yesterday, started today.

Rebooted ECU.
Checked and leveled off fluids. Fluid looked and smelled good, trans never overheats and still runs at 168. Highest temp I’ve ever seen is 172.

When coming to a stop, the truck will gently “pulse” with power. It will continue for a few seconds at complete stop. Pulses the engine RPMS a few hundred, then it stops.

Runs thru the gears fine, seems to engine brake a little more than normal.

6th gear, 1500 RMP, gentle acceleration - it sometimes mildly shudders...

This is an acute problem - started all at once.

I have a big tow coming up next week. 400 miles in the mountains...

 

[thomas5853]

Haven't heard of that, I 59K on mine and haven't experienced anything to that. Only thing is shifting to second while towing isn't smooth.

Sent from my SM-N975U using Tapatalk

 

[mtofell]

Rebooted ECU.

Sounds like a programming thing rather than some physical problem. Wondering if after the reboot the computer needs some time to "learn" you again.

 

[Iron Outlaw]

I'm not a mechanic but I wonder if the torque convertor isn't unlocking when it should be.

And just an FYI, my trans failed (would still drive but slipped badly and go into limp mode) and my fluid looked and smelled normal.

 

[Jughed]

I'm not a mechanic but I wonder if the torque convertor isn't unlocking when it should be.

And just an FYI, my trans failed (would still drive but slipped badly and go into limp mode) and my fluid looked and smelled normal.

Thinking it’s the converter...

I’m going to run it for a bit and see if the programming catches up. But I’m not hopeful

 

[Mr Rich]

I think you're lugging the engine in 6th gear. When I'm in town I manually shift the trans to 4th and/or 5th gear to keep the engine above 2K. I like keeping my 6.4L above 2K unless it's very light load situations on level or downhills.

 

[Jughed]

I think you're lugging the engine in 6th gear. When I'm in town I manually shift the trans to 4th and/or 5th gear to keep the engine above 2K. I like keeping my 6.4L above 2K unless it's very light load situations on level or downhills.

This is happening with no load.

 

[Mr Rich]

This is happening with no load.

Doesn't matter. I'm referring to having the engine at the low end of the power band and the trans is probably in 6th gear. It's going to lug like that. That's why I try to keep the revs up in lower gears so I have snappier acceleration.

 

[Jughed]

Doesn't matter. I'm referring to having the engine at the low end of the power band and the trans is probably in 6th gear. It's going to lug like that. That's why I try to keep the revs up in lower gears so I have snappier acceleration.

Never happed before, 41k miles. Started all at once. It’s pulsing at stop sings, it’s bucking at random times... the whole truck shudders. Sometimes is subtle, sometimes not.

It’s not lugging.

I will find out Wednesday morning. But I believe the torque converter is shot at 41k miles.

 

[Mr Rich]

Have you tried shifting manually? Rev the truck past 2K and hit the shift button. I like the way this 6 speed auto works and I shift manually most of the time and leave it in 4th and 5th around town. I also have 4.11 gears so that makes a bit of difference also.