Tuned 68RFE Shift Patterns

[ZeroSignal]

Alright, I've searched this forum and some other forums which shall not be named... Hoping to hear your experiences/advice with tuned 68RFE shift patterns.

First off, I've got a 2018. It's fully deleted (EGR, DPF, SCR, and throttle valve). MM3 and tunes courtesy of Ray at DRD. I run the 90hp tune as my daily driving tune. I don't switch between HP levels often. After tuning the truck, I did the "easy driving" re-learn process... basically driving in city traffic, stoplight to stoplight no more than 20% throttle letting her climb up and down through the gears for about 40 miles.

After driving the truck with the tuning for the last 5000 miles, I've gotten used to the firmer, more aggressive shifts. What concerns me is the "hard" 4th gear lock. At low speed and light throttle (25% or so) the truck likes to stay in 3rd with the TCC State at "8" on the MM3 (fluid coupling mode). As I increase speed to 40-45mph, if I lift the trottle, she'll shift into 4th and TCC State quickly jumps to "2" (TC Lock). The best way to describe how it feels is a forward lurch... like when you drive a manual transmission and dump the clutch too quickly and lug the engine.

I'm wondering if I should just try to re-load my tune file, and then take her to the dealership and pay them for a quick learn.

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[IGOTACUMMINS]

Alright, I've searched this forum and some other forums which shall not be named... Hoping to hear your experiences/advice with tuned 68RFE shift patterns.

First off, I've got a 2018. It's fully deleted (EGR, DPF, SCR, and throttle valve). MM3 and tunes courtesy of Ray at DRD. I run the 90hp tune as my daily driving tune. I don't switch between HP levels often. After tuning the truck, I did the "easy driving" re-learn process... basically driving in city traffic, stoplight to stoplight no more than 20% throttle letting her climb up and down through the gears for about 40 miles.

After driving the truck with the tuning for the last 5000 miles, I've gotten used to the firmer, more aggressive shifts. What concerns me is the "hard" 4th gear lock. At low speed and light throttle (25% or so) the truck likes to stay in 3rd with the TCC State at "8" on the MM3 (fluid coupling mode). As I increase speed to 40-45mph, if I lift the trottle, she'll shift into 4th and TCC State quickly jumps to "2" (TC Lock). The best way to describe how it feels is a forward lurch... like when you drive a manual transmission and dump the clutch too quickly and lug the engine.

I'm wondering if I should just try to re-load my tune file, and then take her to the dealership and pay them for a quick learn.

@Double R Diesel?


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[trainingwheels]

Alright, I've searched this forum and some other forums which shall not be named... Hoping to hear your experiences/advice with tuned 68RFE shift patterns.

First off, I've got a 2018. It's fully deleted (EGR, DPF, SCR, and throttle valve). MM3 and tunes courtesy of Ray at DRD. I run the 90hp tune as my daily driving tune. I don't switch between HP levels often. After tuning the truck, I did the "easy driving" re-learn process... basically driving in city traffic, stoplight to stoplight no more than 20% throttle letting her climb up and down through the gears for about 40 miles.

After driving the truck with the tuning for the last 5000 miles, I've gotten used to the firmer, more aggressive shifts. What concerns me is the "hard" 4th gear lock. At low speed and light throttle (25% or so) the truck likes to stay in 3rd with the TCC State at "8" on the MM3 (fluid coupling mode). As I increase speed to 40-45mph, if I lift the trottle, she'll shift into 4th and TCC State quickly jumps to "2" (TC Lock). The best way to describe how it feels is a forward lurch... like when you drive a manual transmission and dump the clutch too quickly and lug the engine.

I'm wondering if I should just try to re-load my tune file, and then take her to the dealership and pay them for a quick learn.

Chimin in here because I have the same exact issue. I’ve grown enough to dislike this transmission


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[DRD]

Alright, I've searched this forum and some other forums which shall not be named... Hoping to hear your experiences/advice with tuned 68RFE shift patterns.

First off, I've got a 2018. It's fully deleted (EGR, DPF, SCR, and throttle valve). MM3 and tunes courtesy of Ray at DRD. I run the 90hp tune as my daily driving tune. I don't switch between HP levels often. After tuning the truck, I did the "easy driving" re-learn process... basically driving in city traffic, stoplight to stoplight no more than 20% throttle letting her climb up and down through the gears for about 40 miles.

After driving the truck with the tuning for the last 5000 miles, I've gotten used to the firmer, more aggressive shifts. What concerns me is the "hard" 4th gear lock. At low speed and light throttle (25% or so) the truck likes to stay in 3rd with the TCC State at "8" on the MM3 (fluid coupling mode). As I increase speed to 40-45mph, if I lift the trottle, she'll shift into 4th and TCC State quickly jumps to "2" (TC Lock). The best way to describe how it feels is a forward lurch... like when you drive a manual transmission and dump the clutch too quickly and lug the engine.

I'm wondering if I should just try to re-load my tune file, and then take her to the dealership and pay them for a quick learn.

That is normal for a 68RFE.

What happens is complicated but I'll try to dumb it down.

Chrysler locks the torque converter clutch in gears 3-6. We leave it just that way with our tunes. Whenever the TCC (torque converter clutch) is in full lock, it goes to partial lock during a shift. The tuner will read that state as going from 2 to 8. Once the trans shifts gears, it will go back to full lock. The tuner will read that as going from 8 to 2. Full lock puts all the engines power to the drive with little to no slip. Partial lock technically puts a tad more energy to the wheels that full unlock (which is true 100 percent fluid coupling), but you never feel it as a driver...partial lock might as well be full unlock in the drivers seat.

So all of the above is a process controlled by timers, limiters, etc within the calibration file...many of which we do not have access to or touch within the tuning software we use. Understand that all these TCC parameters are regulated by load, throttle input, engine speed, transmission input and output shaft speeds. Understand the 3-4th gear shift is unique as well. There is large ratio jump between gears 3 and 4. Also most drivers will typically be under the hardest acceleration in that run as well. Put all that together and the 3-4 shift/TCC cycle can happen with the most aggression of all the shifts. Understand we also increase line pressure and speed up the shift functions of the transmission with our tunes in an effort to prevent burning the clutch packs within the trans. If we didn't, a 68RFE would die very soon with added power and torque going through it.

In the case described by OP, what happens is through throttle manipulation, engine speed, load, transmission shaft speeds, etc...all the conditions are met within the PCM to allow the TCC to immediately go to full lock once it hits 4th gear. When that happens, you can feel the instant burst of power to wheels and the truck goes. Some people love that feeling, some don't. Will it break anything...no.

I've said it before and will say it again. If a customer wants the best performing 68RFE behind a tuned Cummins, I recommend two supporting mods. A high performance valve body and an ultra low stall triple disc torque converter from Revmax. Those two items make a 68RFE perform like it should. We tune for Revmax and we have zero issues with their products. They are the best 68RFE people period.

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[ZeroSignal]

Thanks for the quick and thorough response, Ray.

Where I live there's a lot of 35-45mph speed limits, so the truck spends a lot of time in that 3/4 gear range. The "lurch" is more noticable when I'm accelerating out of a turn... after slowing down to turn onto a side street for example.

My future plans include a Revmax transmission upgrade, but I owe my wife a kitchen remodel, first

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[TexNeck]

That is normal for a 68RFE.

What happens is complicated but I'll try to dumb it down.

Chrysler locks the torque converter clutch in gears 3-6. We leave it just that way with our tunes. Whenever the TCC (torque converter clutch) is in full lock, it goes to partial lock during a shift. The tuner will read that state as going from 2 to 8. Once the trans shifts gears, it will go back to full lock. The tuner will read that as going from 8 to 2. Full lock puts all the engines power to the drive with little to no slip. Partial lock technically puts a tad more energy to the wheels that full unlock (which is true 100 percent fluid coupling), but you never feel it as a driver...partial lock might as well be full unlock in the drivers seat.

So all of the above is a process controlled by timers, limiters, etc within the calibration file...many of which we do not have access to or touch within the tuning software we use. Understand that all these TCC parameters are regulated by load, throttle input, engine speed, transmission input and output shaft speeds. Understand the 3-4th gear shift is unique as well. There is large ratio jump between gears 3 and 4. Also most drivers will typically be under the hardest acceleration in that run as well. Put all that together and the 3-4 shift/TCC cycle can happen with the most aggression of all the shifts. Understand we also increase line pressure and speed up the shift functions of the transmission with our tunes in an effort to prevent burning the clutch packs within the trans. If we didn't, a 68RFE would die very soon with added power and torque going through it.

In the case described by OP, what happens is through throttle manipulation, engine speed, load, transmission shaft speeds, etc...all the conditions are met within the PCM to allow the TCC to immediately go to full lock once it hits 4th gear. When that happens, you can feel the instant burst of power to wheels and the truck goes. Some people love that feeling, some don't. Will it break anything...no.

I've said it before and will say it again. If a customer wants the best performing 68RFE behind a tuned Cummins, I recommend two supporting mods. A high performance valve body and an ultra low stall triple disc torque converter from Revmax. Those two items make a 68RFE perform like it should. We tune for Revmax and we have zero issues with their products. They are the best 68RFE people period.

Sent from my SM-G960U using Tapatalk

All things considered with the upgraded valve body and TC from RevMax as suggested (I am guessing do billet flex plate while right there) is that a relatively safe setup to support about 625hp setup with your tuning? (Common sense when driving applied)

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[DRD]

All things considered with the upgraded valve body and TC from RevMax as suggested (I am guessing do billet flex plate while right there) is that a relatively safe setup to support about 625hp setup with your tuning? (Common sense when driving applied)

I would say you would be good to around 550 RWHP mark with those mods. Beyond that you are hit and miss with longevity and would need to consider a fully built transmission.

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[niteghost]

That is normal for a 68RFE.

What happens is complicated but I'll try to dumb it down.

Chrysler locks the torque converter clutch in gears 3-6. We leave it just that way with our tunes. Whenever the TCC (torque converter clutch) is in full lock, it goes to partial lock during a shift. The tuner will read that state as going from 2 to 8. Once the trans shifts gears, it will go back to full lock. The tuner will read that as going from 8 to 2. Full lock puts all the engines power to the drive with little to no slip. Partial lock technically puts a tad more energy to the wheels that full unlock (which is true 100 percent fluid coupling), but you never feel it as a driver...partial lock might as well be full unlock in the drivers seat.

So all of the above is a process controlled by timers, limiters, etc within the calibration file...many of which we do not have access to or touch within the tuning software we use. Understand that all these TCC parameters are regulated by load, throttle input, engine speed, transmission input and output shaft speeds. Understand the 3-4th gear shift is unique as well. There is large ratio jump between gears 3 and 4. Also most drivers will typically be under the hardest acceleration in that run as well. Put all that together and the 3-4 shift/TCC cycle can happen with the most aggression of all the shifts. Understand we also increase line pressure and speed up the shift functions of the transmission with our tunes in an effort to prevent burning the clutch packs within the trans. If we didn't, a 68RFE would die very soon with added power and torque going through it.

In the case described by OP, what happens is through throttle manipulation, engine speed, load, transmission shaft speeds, etc...all the conditions are met within the PCM to allow the TCC to immediately go to full lock once it hits 4th gear. When that happens, you can feel the instant burst of power to wheels and the truck goes. Some people love that feeling, some don't. Will it break anything...no.

I've said it before and will say it again. If a customer wants the best performing 68RFE behind a tuned Cummins, I recommend two supporting mods. A high performance valve body and an ultra low stall triple disc torque converter from Revmax. Those two items make a 68RFE perform like it should. We tune for Revmax and we have zero issues with their products. They are the best 68RFE people period.

Sent from my SM-G960U using Tapatalk

Ray - ever since I tuned my truck with your emissions and trans tuning I haven’t felt comfortable with the 68. As a result I have researched and read everything I could find about the 68 which lead to more confusion on my part. But this post finally turned the light bulbs on for me.... so thanks for taking time to write it. Would you answer this for me. I have 55000 thousand on my truck now(2018 2500 crew 4x4, all stock with drd emissions tuning), I’m planning on full deletes around 80k. When I do full delete I’m going to do the Revmax TCC and VB. Would it be smart to go ahead and do a Valair clutch kit w/t new plates along with the TCC and VB? I think I’m going to pass on the flex plate, or should I do it wile I’m there? Is there anything else I should do wile I’m in there? This truck is my daily driver, I take care of it and I’m pretty easy on it but I do like to mash on it from time to time. If I did the trans work before the deletes would that require new trans tuning? I would really appreciate your thoughts on this.

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[DRD]

Ray - ever since I tuned my truck with your emissions and trans tuning I haven’t felt comfortable with the 68. As a result I have researched and read everything I could find about the 68 which lead to more confusion on my part. But this post finally turned the light bulbs on for me.... so thanks for taking time to write it. Would you answer this for me. I have 55000 thousand on my truck now(2018 2500 crew 4x4, all stock with drd emissions tuning), I’m planning on full deletes around 80k. When I do full delete I’m going to do the Revmax TCC and VB. Would it be smart to go ahead and do a Valair clutch kit w/t new plates along with the TCC and VB? I think I’m going to pass on the flex plate, or should I do it wile I’m there? Is there anything else I should do wile I’m in there? This truck is my daily driver, I take care of it and I’m pretty easy on it but I do like to mash on it from time to time. If I did the trans work before the deletes would that require new trans tuning? I would really appreciate your thoughts on this.

My recommendations are the Revmax valve body and their ultra low stall torque converter. The billet flex plate is a good option but not required if you are not going to ever go beyond what the power a stock turbo is capable of making.

A retune is not required for the above mods, but you will not see an increase in line pressure that the new valve body allows if you don't get a retune.

Ray,
Double R Diesel

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[Dwelsh]

Good thread. I was curious as to how much power the trans would handle with the revmax valve body and converter I was gonna start a thread but this answered it. A truck with head studs 2nd gen swap and the rev max trans upgrades aughta be a pretty reliable truck that puts down good power for about 6 grand.

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