Safe 6l80 adjustments for light towing and longevity

[legierk]

I get my 2014 GMC Sierra back from the trans shop today. Developed the shudder issue at 151k miles. Truck has been babied, had 2 prior trans fluid changes, and I stopped driving it after it developed the shudder. Its getting new billet converter with factory stall (Precision of New Hampton),
and a Transgo SK kit for front pump installed. (I could have done all this, but don't have the time or energy).

My first task will be to:
1) Disable DOD/AFM - vibrations/harmonics cause excessive wear on TCC and input shaft.
2) Disable TCC lockup in 1-3 gears (change to 318mph apply and 317mph release)

a) I am still a little unsure if I should also disable TCC lockup in 4th gear. This is not a race car, but a daily driver truck that tows occasionally. My WIFE said" If you are towing, wouldn't you want it to lock up in 4th?"!!!

b) I have watched this video many times: https://www.youtube.com/watch?v=PEONayqUVF4

3) Should I reduce TCC slip? To what? I have seen take all to 0 and some others to change the entire table to 10rpm. What is safe?
4) If I change the slip, do I also need to add 5%-10% to the line pressure (TCC Apply Pressure Ramp)? Again, what is safe?
5) What other SAFE and PROVEN changes can I make to make this trans and torque converter last?

I bought HPTuners just to do these mods to save my trans. I just want my truck to last. No racing or burnouts or mudding. Just occasionally pulling trailers loaded with my Camaro, cattle or hay. I am not an HPTuners expert. I do however have a Camaro with 496/Fitech EFI that does ProTouring events and a 51 truck with LQ4/4L80 that I tune with the Holley TerminatorX. So I am familiar with working around cars, just not HPTuners. Thank you for any help.

[hjtrbo]

You're on the right track. TCC slip to 0. Log TCC slip and TCC pressure to guide you if you need to up the pressure. No point upping the pressure and making everything work harder for no reason right?

Advanved search for threads replied to by 5FDP. He has helped heaps of guys with their 6L80 truck tunes over the years. One of the threads he provides his tune. It'll be well worth your time reading if you can book in some couch time. To much knowledge given to cover in this single post.

[legierk]

hjtrbo,, thanks. Good info. Not quite sure how to "monitor", but I assume I just use the scan tool while I am driving. Also, I read many posts by 5FDP, and I also saw his tune. I am unsure if I can open his tune in VCM without having to have credits for it? I guess if I don't try to flash my ecm/tcm I won't need extra credits? Newbie at HPTuners.

[hjtrbo]

Good to use hp tuners scanner to monitor. Worth getting to know it. You can open his tune without credits. When you're ready to spend the credits to license your truck you can upload your trans tune and merge his settings across then download the new tune to the truck.

If you need help getting the scanner set up have a crack first yourself then post back. Happy to help get you set up with the right channels and charts so long as you are willing to put in the effort of climbing the step learning curve.

Don't be to concerned about making changes yet, get to know the scanner. And research these forums and you tube.

[legierk]

Excellent. Thank you.

[legierk]

Just uploaded a few changes. My first time. So, wanted someone with more knowledge than me (which would be about anybody), to verify that I haven't missed anything or done anything really stupid.2014 GMC FACTORY TUNE FILE.hpt2014 GMC 1ST MODIFIED TUNE FILE.hpt

[hjtrbo]

All good here. Just depends whether you like it or not? Will certainly feel a little different with the converter unlocked for the first few gears.

How are you going with the scanner? Add the following to your scan list if you haven't already.
Trans fluid temp, Trans torque, PRNDL Status, Trans shift mode, Trans current gear, TCC slip, TCC Pressure, Time of latest shift, PCS 1 Cmd Pressure, Trans slip rpm, Trans input shaft rpm, Trans output shaft rpm. Will get you some good data to look at as you move forward.

You can spend months mucking around with shift points and lock up points till you get them to a state you are really 98% happy with. Also have shift pressure and timing to muck around with when you're ready...

[legierk]

Well, uploaded the above tune last night and the ride to work was like driving a new truck. Having said that, I believe that disabling DOD did more than the trans changes. Even after the new converter and trans mods, it was still jerking a little, so it may have been the DOD/AFM the whole time (although there is a known issue with these torque converters.) In any event, I am happy that it is running well again.

WRT to using the scanner, I will try it soon while driving. I question whether or not I can drive while looking at a laptop screen though! LOL. I do want to tweak the AFR at some points, as I understand GM made these run rich on purpose (for warranty reasons). I haven't verified this personally with the scanner, but that is what I will try to do. I wish there was a way to copy my fuel tables from the Holley TerminatorX to the HPTuners. My 6.0L runs great. Maybe there is a way to lean the entire table out by percentage, a percent at a time or something. IDK. Will look into it. Thanks for all the help.