2021 1500 transmission issues/quirks

[frostymug]

Hi all, I have a 2021 1500 Limited with 4,200 miles. Ever since around 3,000 miles, the transmission shifts very differently and not as smooth at lower speeds during acceleration and deceleration. Some examples:

• When going off the line from a stop, the shift from 1st to 2nd and from 2nd to 3rd are not as smooth as they used to be. It's almost like it takes longer and then the shift is more heavy and kinda lurches the truck forward.
• When going ~20-25mph and letting off the gas pedal to slow down, transmission doesn't seem to downshift quickly enough because there is a major and very strange lack of throttle when pressing the gas pedal. For a second or two, the lack of response almost feels like you are in neutral, until the downshift finally triggers and the truck lurches forward.
• Hard downshifts when braking. If I’m in let’s say 6th gear and I start braking to slow down, the transmission downshifts hard from 6 to 5, then 5 to 4, etc. Each time, it feels like all of a sudden the brakes were applied harder but it’s really the downshift and the accompanying rev up. Then it does it again for each gear it lowers to. Feels like a series of nose dives. Super strange. Never felt this happening with any other automatic transmission.

When in higher gears and speeds, no noticeable changes and all works just as good as day one.

Has anyone else experienced something like this? Does it have to do with the programming in the transmission? If so, can I reset the programming myself or is this something I need to tell the dealer to look at? I dread pointing out anything to the dealer, as you always get the typical runaround "it's functioning normally". Whatever this is, it is not normal and it's VERY different than it drove the first 3k miles, which were smooth as butter and very responsive.

Any and all info or suggestions would be greatly appreciated!

 

[Devo]

I believe I'm having almost the exact same issue as you. I have a Bighorn with 866 miles on it currently and when hard accelerating from stop it seems almost like the transmission "slips" and goes far past the power-band for the hemi.
A buddy of mine has a 2020 Rebel and said he had the same issue and went to the dealership who flashed the TCM and all has been well since.
I have an appointment Monday to have my dealership check it out.

 

[Ram Dude]

Break-in period...Give it time. I think all our trucks experience some quirkiness during first 5,000 miles. Think mine did too but at just over 5K miles now she’s smooth as butter.

 

[Morenar]

Hi all, I have a 2021 1500 Limited with 4,200 miles. Ever since around 3,000 miles, the transmission shifts very differently and not as smooth at lower speeds during acceleration and deceleration. Some examples:

• When going off the line from a stop, the shift from 1st to 2nd and from 2nd to 3rd are not as smooth as they used to be. It's almost like it takes longer and then the shift is more heavy and kinda lurches the truck forward.
• When going ~20-25mph and letting off the gas pedal to slow down, transmission doesn't seem to downshift quickly enough because there is a major and very strange lack of throttle when pressing the gas pedal. For a second or two, the lack of response almost feels like you are in neutral, until the downshift finally triggers and the truck lurches forward.
• Hard downshifts when braking. If I’m in let’s say 6th gear and I start braking to slow down, the transmission downshifts hard from 6 to 5, then 5 to 4, etc. Each time, it feels like all of a sudden the brakes were applied harder but it’s really the downshift and the accompanying rev up. Then it does it again for each gear it lowers to. Feels like a series of nose dives. Super strange. Never felt this happening with any other automatic transmission.

When in higher gears and speeds, no noticeable changes and all works just as good as day one.

Has anyone else experienced something like this? Does it have to do with the programming in the transmission? If so, can I reset the programming myself or is this something I need to tell the dealer to look at? I dread pointing out anything to the dealer, as you always get the typical runaround "it's functioning normally". Whatever this is, it is not normal and it's VERY different than it drove the first 3k miles, which were smooth as butter and very responsive.

Any and all info or suggestions would be greatly appreciated!

@frostymug I am seeing similar issues with my 2021 as well. I just hit 5000 miles on mine. Have you seen improvement or gone to the dealer? I haven't seen a TSB for the 2021 Ram transmission.

 

[popcenator]

I'm at just over 20K and it's still a thing. It's a quirk of the transmission. I've tried several of the TSB PCM/TCM flashes with no permanent fix. Some days it's perfectly fine, some it's jerky.

Sent from my SM-N986U using Tapatalk

 

[Sascwatch]

I notice the 1-2 harsh/delayed up shift myself under light throttle, under heavier throttle or while towing a trailer all shifts are nice and smooth.

My dealer did a tcm update along with resetting the learned parameters and it helped for a couple of days at most.

 

[jgreene]

I was told the transmission adjusts to your driving. So if you are the type to get on the freeway and cruise at 75. The transmission adjusts for best fuel mileage. I believe there are 8 different settings it can adjust itself into?

 

[z0n3]

My 2021 does similar things, but I notice if I’m coasting through a parking lot it loves to sit in 1st then after a second or two of accelerating it’ll finally shift into 2nd. I’m at just under 5k. I can see something like this being handled by a TCM flash but I don’t have plans to take it in yet. I had a 2019 bighorn and it never had these weird kind of shifts so this might be some additional programming the 21s need from the dealership.

 

[popcenator]

I was told the transmission adjusts to your driving. So if you are the type to get on the freeway and cruise at 75. The transmission adjusts for best fuel mileage. I believe there are 8 different settings it can adjust itself into?

There are like 40 individual shift maps with the 8HP75 tuning.

Sent from my SM-N986U using Tapatalk

 

[Morenar]

Came across this today

https://static.nhtsa.gov/odi/tsbs/2021/MC-10190734-9999.pdf

SYMPTOM/CONDITION: Customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation the technician may find one or more of the following Diagnostic Trouble Codes (DTCs). • P1D90-00 Incorrect Gear Ratio - Clutch 2 Defective. • P1D91-00 Incorrect Gear Ratio - Clutch 3 Defective. • P1D92-00 Incorrect Gear Ratio - Clutch 4 Defective. • P1D93-00 Incorrect Gear Ratio - Clutch 5 Defective. • P1D95-00 Tcm Clutch Failure Undetermined. • P1B14-00 Park-By-Wire - Unintended Park Position. • P1B13-00 Park-By-Wire - Unintended Out Of Park Position. • P1D99-00 Incorrect Gear Ratio: Clutch B Or E Defective. • P1D9A-00 Incorrect Gear Ratio: Clutch C Or D Defective. • P1D95-00 Tcm Clutch Failure Undetermined. • P07E4-00 Unable To Engage Park. • P1DCD-00 Tcm Monitoring Processor Performance - Multiple Clutches Locked Up. • P0735-00 Gear 5 Shift Incorrect Ratio. • P0919-00 Gear Shift Position Control Error.

Customers may also experience the following:
• Transmission fluid leaking under vehicle.
• The vehicle will not shift.
• Slow shifting between gears.

 

[Apple ii]

I have a 2021, 2500 HD, after initial picking up from dealership drove to Florida and back pulling a fifth-wheel (14,000lbs)
I have the diesel motor with tow package and have the exact same issues. I cannot pass anyone as it will not drop down a gear to pass, and when driving through small towns at 25 to 30 miles an hour it seems like it's going to die as it will not drop down a gear.
I have tried it both ways with Towing on and off with no change either way. It's at the dealership as we speak and they're saying there's nothing wrong with it. Should have stuck with the 2006 Chevy Silverado, had no issues whatsoever pulling the same trailer.

 

[jdefoe0424]

I have a 2021, 2500 HD, after initial picking up from dealership drove to Florida and back pulling a fifth-wheel (14,000lbs)
I have the diesel motor with tow package and have the exact same issues. I cannot pass anyone as it will not drop down a gear to pass, and when driving through small towns at 25 to 30 miles an hour it seems like it's going to die as it will not drop down a gear.
I have tried it both ways with Towing on and off with no change either way. It's at the dealership as we speak and they're saying there's nothing wrong with it. Should have stuck with the 2006 Chevy Silverado, had no issues whatsoever pulling the same trailer.

The Cummins has the 68rfe behind it in the 2500, completely different from the 8 speed found behind the 5.7 and 6.4 hemi's. I have heard of many complaining of the "dead pedal" that these trucks may have.
You may get more information by posting on the sister site, www.hdrams.com


As for everyone else, ALL ZF 8 speeds have the weird 1-2 problem while rolling through stop signs. It just depends on what shift points are running, I don't recall experiencing it in my 2500 but I did in my 1500 and the BMW I had before that. I think it has to do with it being such a short gear that it can't decide if it needs it or not, and then when it does decide you've already mashed your foot farther into the pedal...then it decides it has to go to 1st and takes off like a rocketship.

 

[T.t]

Hi all, I have a 2021 1500 Limited with 4,200 miles. Ever since around 3,000 miles, the transmission shifts very differently and not as smooth at lower speeds during acceleration and deceleration. Some examples:

• When going off the line from a stop, the shift from 1st to 2nd and from 2nd to 3rd are not as smooth as they used to be. It's almost like it takes longer and then the shift is more heavy and kinda lurches the truck forward.
• When going ~20-25mph and letting off the gas pedal to slow down, transmission doesn't seem to downshift quickly enough because there is a major and very strange lack of throttle when pressing the gas pedal. For a second or two, the lack of response almost feels like you are in neutral, until the downshift finally triggers and the truck lurches forward.
• Hard downshifts when braking. If I’m in let’s say 6th gear and I start braking to slow down, the transmission downshifts hard from 6 to 5, then 5 to 4, etc. Each time, it feels like all of a sudden the brakes were applied harder but it’s really the downshift and the accompanying rev up. Then it does it again for each gear it lowers to. Feels like a series of nose dives. Super strange. Never felt this happening with any other automatic transmission.

When in higher gears and speeds, no noticeable changes and all works just as good as day one.

Has anyone else experienced something like this? Does it have to do with the programming in the transmission? If so, can I reset the programming myself or is this something I need to tell the dealer to look at? I dread pointing out anything to the dealer, as you always get the typical runaround "it's functioning normally". Whatever this is, it is not normal and it's VERY different than it drove the first 3k miles, which were smooth as butter and very responsive.

Any and all info or suggestions would be greatly appreciated!

Hi,
Did you solved your issue ? i have same problem.

 

[Nightowl]

I bought a 2020 1500 back in January, 1500 3.6L. 17K miles. I have 20K+ now. If I am babying it, 1st to 2nd to 3rd is jerky, If I accelerate fast, it is smooth. The other issue is going slow, I go thru town and a school zone every morning, 20-25 mph. The trans shifts up to 5th at those slow speeds and the engine feels like it is lugging. Is that normal at those slow speeds?

 

[RamCares]

Hi,
Did you solved your issue ? i have same problem.

Hey there,

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Callie
Ram Cares