New to me 6L80E, would like to tune for most longevity

[dka56]

I picked up this 2012 Yukon XL Denali last year and it currently has 104K miles, very well cared for. I'm only putting 10K miles per year max, minimal towing, and would like to do what I can to keep the trans healthy.

I've read up on the line pressure thread stating raising via HPT might not do much to a stock unit. I do understand the factory slipping/lockup programming in the lower gears so it seems the consensus is to either remove the slip, or remove lockup in the lower gears is the easiest?

Another option is to remove the trans and replace the converter early, would be a pita since mine is AWD.

I love this vehicle despite the fuel prices, plan on keeping it for a while. How detrimental is the MPG hit with removing lockup in the lower gears?

Would it be better to remove any slip in the lower gears as opposed to removing lockup? How jerky would it be if all slip is removed?

The engine definitely does fine lumbering along at 1000-1200 RPM at around a steady 40-45 MPH cruise, my concern is if the smoothness is coming from increased slip at those speeds, or does it make a difference.

All input appreciated.

[Lakegoat]

Change the oil and filter, get an aftermarket thermostat (on the side of the trans) and get a new converter. The converters cause most of the damage, and that is due mostly to the early lockup in lower gears. If you are going to take it out to change a converter after 10 years, might as well get some new parts and check the pump.

[dka56]

Didn't know about the thermostat, thanks.

If I do pull the trans, I will definitely try to source a pump assembly and possibly have mine rebuilt/machined...I do hear they are hard to get though.

I saw the post from circa 2010 about the program for the trans, but naturally that was some time ago.

Curious about drivability reducing slip in lower gears to zero or close to zero.

[Alvin]

I wouldn't raise line pressure. You can shorten shift times. Raising line pressure in 6lXX's in my opinion is the wrong move.

I've got 280K on my daily driver.. Towed quite a lot with it.. I should shut up before it craps out lol!

[dhoagland]

I wouldn't raise line pressure. You can shorten shift times. Raising line pressure in 6lXX's in my opinion is the wrong move.

I've got 280K on my daily driver.. Towed quite a lot with it.. I should shut up before it craps out lol!

LOL!!!!
Is your suggestion on line pressure, for a stock 6L80 transmission, based on the "Coneing" of certain clutches and breaking of other pistons?

[Alvin]

LOL!!!!
Is your suggestion on line pressure, for a stock 6L80 transmission, based on the "Coneing" of certain clutches and breaking of other pistons?

No, its just biased on what works.

The older 4 speeds responded really well with higher line pressure and little to no TM.

The majority of the work in a 6,8,10 speed is just getting the shift times setup for something reasonable while retaining TM. I very very rarely need to modify shift pressures in a 6L80 trans. Even on builds that make a lot of power. The TCC will need pressure adjustments but not shifting.

[dhoagland]

No, its just biased on what works.

The older 4 speeds responded really well with higher line pressure and little to no TM.

The majority of the work in a 6,8,10 speed is just getting the shift times setup for something reasonable while retaining TM. I very very rarely need to modify shift pressures in a 6L80 trans. Even on builds that make a lot of power. The TCC will need pressure adjustments but not shifting.

Got Ya
I actually like more TM.
My opinion, for the .xx that you might gain at the track isn't worth the premature failure without it

[dka56]

Thank you for the info.

So can I simply remove some slip with HPT to (hopefully) increase the lifespan of the converter? Does this cause any annoying driving issues?

At a steady speed of about 45 MPH, the engine is at a lazy sub-1500 RPM in I believe 6th gear. My thoughts are this is where a good bit of slip may be happening to keep the driveline nice and smooth.

I don't know, just speculating.

[NotSure]

You can use the Bluecat tool to space out your shift points better so it is not lugging around in a high gear. The tool can be found on this site. Many people disable tcc in all but the top gear(s) to help as well. You can zero out the tcc slip tables, but you will likely have to bump up the tcc regulator offset to hold it, and/or adjust the throttle settings for tcc disengage. Be careful not to have overlap amongst all of the tcc and shift points. Bluecat tool will help with that.

[NotSure]

Forgot to mention, you may get more driveline clunking doing the above. The stock shifting strategy of lugging the motor around certainty masks play in the driveline.

To check tcc slip, log throttle, vehicle speed, tcc pressure, and tcc slip, then go drive on highway at steady speed while slowly crowding the throttle until tcc disengages. This will tell you if you need to bump up tcc regulator offset or adjust your tcc enable/disable throttle or speed.

[dhoagland]

Post up your tune, and if all of your tables line up with mine I'll post it for you to try.

Mine is a copy of a 2011 CTSV...
It was suggested that this was a great platform to copy for my 2011 SS... Which it is..

Only problem is the axis on some of the tables are different, as is the shift pattern designation, so you need to be careful...
I did a complete segment swap, and it wasn't good