2017 Tahoe 5.3 6L80 Tune for Longevity - Can I do it?

[TheDoofus]

Hello all,

I have a 2017 Chevy Tahoe with a 5.3 / 6L80 that has close to 70K miles on it. I started looking around the internet for best practices on transmission fluid service and was horrified to find that the 6L80 seems to have a high failure rate. Several hundred hours of YouTubes videos / forum posts later, I am trying to figure out how far I should go in trying to prevent failure / increase life.

What I have done so far and what I am planning to do:

1. Replace the transmission thermostat with the Superior Solutions kit (temps now about 50 degrees above ambient vs 180 ish).
2. Replace the fluid / filter (probably within 2 weeks), adding a pan with a plug so I can partially change some of the fluid every oil change.
3. Add an external spin on filter on the transmission out line to the cooler that I can change at every oil change (without a pan drop).
4. (Why I am here) Tune the engine to "turn off" DFM / AFM / DOD (what ever you want to call it) and tune the transmission (see below).

So in terms of tuning the transmission ... what I have gathered is that there is some level of agreement that eliminating TCC engagement in 1-4 can't really hurt anything and can only prolong the life of the unit (anyone disagree?). There seems to be some level of debate around TCC slip though. Some parties claim 0 slip should be best for life (but maybe not ride feel), while others have claimed 0 slip might cause too much pressure and cause a catastrophic failure. I'm thinking of splitting the difference and going for something like 10 in 5th and 5 in 6th.

So here are my questions:

1. Am I stupid to spend the money on the scanner and the credits to do this?
2. How difficult is this for someone with no experience with the tool / tuning at all? I am a software developer by trade, and it seems somewhat similar to PLC programing (if anyone is familiar with that) in terms of the read / write / data tables.
3. What can go horrifically wrong and what should I do / know before I start?
4. Anything about the above proposed changes you would do differently?

About me and the vehicle:
This is really my wife's car. She babies it (doubt she has ever used more than 50% throttle). It does have a tow package (and the cooler), but it never tows anything. It is our "trip" car for long distance travel. I usually drive it for these trips and I use tow haul mode to monitor transmission temps and really like the way it drives in that mode (holds gears longer, engine braking more similar to a manual). It is garage kept and pretty spotless. I change the oil every 5-7K with mobile 1 full synthetic, and do my best to maintain the car at an excellent level. We bought it brand new and plan to keep it at least another 7-10 years (150k-200K miles), maybe longer. I am fairly mechanically inclined and will usually perform all maintenance / repair tasks myself, unless I am afraid I will kill / maim myself in process (think fuel pumps / fuel tanks / other fun things that blow up).

I know this isn't purely a transmission tune question (though the meat of it is), so I hope it is ok here. I also know there is a lot of objectivity to my questions, but more or less asking "what would you do given the following information?".

Thanks for reading!

[[email protected]]

Disabling the DOD is a must on these engines, as far as tranny tuning your on the right page, disableing lockup on 1-4 wont hurt anything, ive tuned a few of these trannys with good success , ill post one of my tunes for you to compare to. as far as torque convertor lockup. and if anyone thinks im not acually helping these trannys out, then pipe in with your opinoins. that what this forum is for

[[email protected]]

keve lehman 14 silverado dod disabled slip set to 0.hpt

[TheDoofus]

keve lehman 14 silverado dod disabled slip set to 0.hpt

Thank you! I am checking it out now.

[04silverado6.0]

I have been having better luck leaving the slip tables set to 3-5rpm. Gives a much better driving experience and less shudder/jerking.

[[email protected]]

ok thanks for the input ill try that out on my next one

[1TANK]

That is very similar to my 6L80 tune - probably on 20-30 trucks with ZERO complaints. Only difference : I havent messed with TCC ADAPT or gain/offset. I don't lock until 5th and take some Torque Adder out to speed the shift up.

[TheDoofus]

keve lehman 14 silverado dod disabled slip set to 0.hpt

Thanks again for providing this.

I noticed that you didn't change the "WOT" tables for the TCC apply / release. I assume these are "Wide Open Throttle" settings, only active when the pedal is to the floor?

I am thinking about dropping TCC lock in these tables as well, but curious as to why you left them as is.

Here is what I have so far:

2017_Tahoe_no_TCC_in1_4_load.hpt

Note I haven't touched the slip tables yet. Wanting to make small incremental changes.

Thanks!

[[email protected]]

i quess i figured locking up tcc with factory wot tables will help acceleration. more direct drive. it wont hurt to turn that off as well but you will lose acceleration on wot

[TheDoofus]

Ok, makes good sense. Thanks!

[04silverado6.0]

Most combos do not run any faster 1/4 mile times with the converter locked. The exception would be a combo that would like the extra load, turbo setups.

[abc]

I've never looked at one of these files nor tuned on one of theses specific transmissions but if you apply normal thought process to keeping a electronic trans alive, why has nobody mentioned much about torque management for the trans? In strictly terms of extending the life of the trans. would one of the best practices be to decrease as much torque input as possible during a shift? The compromise is comfort. Basic rule of thumb, the less slip you have in a clutch system the longer it will last. In order for a OEM to get comfort they need to let the clutching mechanisms slip and or absorb torque, that is the action that ultimately causes them to fail.

There seems to be a lot of mention about the TCC but as long as the TCC doesn't send shrapnel into the fluid it has little to do with the rest of the trans. as far as longevity. I would lean toward keeping it locked up as much as possible to help keep heat generation down and keep the eng. rpm lower for a daily driver. I know the lock up schedule is a compromise of many factors and locking it up as quick as possible in most scenarios is the best approach to extend TCC life. Obviously there is a lot more to it than a couple paragraphs can describe, but in general, shift it quicker, with more psi, and little torque applied as possible to help extend the life.

You mentioned you like some of the things it does in tow/haul mode, some of what I mentioned is likely what they are doing when you push that button. The OEM's are walking a tight rope with compromise of many variables, cost and satisfaction level from the customer likely being at the top of the list. How inexpensive can they make/buy it and still have the customer satisfied so they are repeat customers? They could build the trans to last twice as long as it does with a control strategy that would support that, but how much would it cost and when would you buy another one?

In my opinion if you approach the control strategy as if you were about to double the output of the engine how would you change the strategy for the trans. to support the additional input? Some of the answers are above.

[04silverado6.0]

Id really recommend leaving about 3-5 rpm of slip in the tables. These clutches will not lock up tight and will slip regardless, giving spikes in pressure which is not comfortable to the driver.

[mikez71]

TheDoofus : Do you mind posting your stock factory tune?

[TheDoofus]

TheDoofus : Do you mind posting your stock factory tune?

Not at all.

Stock_2017_Tahoe_5_3__6L80.hpt

[TheDoofus]

I've never looked at one of these files nor tuned on one of theses specific transmissions but if you apply normal thought process to keeping a electronic trans alive, why has nobody mentioned much about torque management for the trans? In strictly terms of extending the life of the trans. would one of the best practices be to decrease as much torque input as possible during a shift? The compromise is comfort. Basic rule of thumb, the less slip you have in a clutch system the longer it will last. In order for a OEM to get comfort they need to let the clutching mechanisms slip and or absorb torque, that is the action that ultimately causes them to fail.

There seems to be a lot of mention about the TCC but as long as the TCC doesn't send shrapnel into the fluid it has little to do with the rest of the trans. as far as longevity. I would lean toward keeping it locked up as much as possible to help keep heat generation down and keep the eng. rpm lower for a daily driver. I know the lock up schedule is a compromise of many factors and locking it up as quick as possible in most scenarios is the best approach to extend TCC life. Obviously there is a lot more to it than a couple paragraphs can describe, but in general, shift it quicker, with more psi, and little torque applied as possible to help extend the life.

You mentioned you like some of the things it does in tow/haul mode, some of what I mentioned is likely what they are doing when you push that button. The OEM's are walking a tight rope with compromise of many variables, cost and satisfaction level from the customer likely being at the top of the list. How inexpensive can they make/buy it and still have the customer satisfied so they are repeat customers? They could build the trans to last twice as long as it does with a control strategy that would support that, but how much would it cost and when would you buy another one?

In my opinion if you approach the control strategy as if you were about to double the output of the engine how would you change the strategy for the trans. to support the additional input? Some of the answers are above.

Thanks for your reply. I will read up on the torque management to see what I might be comfortable changing. As far as the TCC and the discussion around it, your quote is pretty much dead on:

as long as the TCC doesn't send shrapnel into the fluid

From what I understand the clutch friction material (some sort of woven carbon?) fails and then grenades the transmission. This is the cause of a very large percentage of these transmission failures (from what I see online, and the local transmission shops I called). I would dare to say the consensus is that its a very good transmission outside of the TCC (and maybe the Pressure Regulator Valve). This is all "hearsay" though and what I have gathered. Not saying I am or will end up being right about this, just what I understand so far and explaining my mitigation strategy.

[TheDoofus]

Id really recommend leaving about 3-5 rpm of slip in the tables. These clutches will not lock up tight and will slip regardless, giving spikes in pressure which is not comfortable to the driver.

Thanks, I think I will go with what you suggest.

[mikez71]

Thank you TheDoofus!!!

I update the shift scheduling in my 2012 Tahoe with later tunes.
Was using the 2015 Tahoe, big improvement from 2012!
Your 2017 looks even better!

I prefer leaving the TCC locked in 4th because I do lots of around town commuting at slower cruising speeds..

[Fast4.7]

Thank you TheDoofus!!!

I update the shift scheduling in my 2012 Tahoe with later tunes.
Was using the 2015 Tahoe, big improvement from 2012!
Your 2017 looks even better!

I prefer leaving the TCC locked in 4th because I do lots of around town commuting at slower cruising speeds..

I prefer lockup as early as 2nd gear in a 4spd and 3rd gear in a 6spd myself. Works better crawling along in traffic in the crazy summer heat where I live. If it is never driven in ambients over ~100F and never sees stop and go traffic or long periods of 35-50 mph where it can be unlocked in 3rd or 4th alot you can delay lockup to 5th gear. Personally in DFW, Texas area I do not leave them unlocked more than necessary because of the heat they can build up in summer in a heavier vehicle.

[mikez71]

Exactly my reasoning as well Fast4.7! (California heat and traffic)
I seem to hit 180deg trans temp pretty regularly/easily.

There is a particular instance where I think lockup in 2nd would help.

Going down a steep street at a local park, I brake to slow my speed.. near the bottom I want to nudge the gas a little bit.
But the coasting outruns the converter, so there is a bit of slack before engaging..
(probably 2nd gear) For that situation, I guess locking in 2nd would help..