6l80 tcc slip tuning stock clutch

[mikez71]

Found some interesting info on hptuners forum from Robert at Transgo...

"As for making it not slip the converter clutch in 5th and 6th that's mostly only good for aftermarket converter that don't use the GM woven carbon lining and so prone to shudder. The carbon woven lining is very brittle and designed to slip without wearing out, but it is super brittle . the extra pressure required to make it not slip and the increase rate of apply is ******* it and it often will crack and lose chunks of it causing the TCC to start slipping after many thousandths of mile with this modification. Eliminating lock up in 1-2-3-4 is not going to hurt anything, but I would not recommend increasing the pressure to stop it from slipping the 20 or so RPM factory programing does."

Little more info here...

2010 Tahoe with 6L80, tune for longevity and towing

I have a 2010 Tahoe 5.3 (LMG) with the HD trailering package (8200lb rating) and occasionally tow a 7500lb trailer. It has 170k miles and is currently running and shifting well. I recently purchased an MPVI3 for this vehicle and want to do the following: -Disable AFM -Disable flex fuel. I only...

forum.hptuners.com

 

[Marky Dissod]

Is this worth anything?

6L80's eating converters issues. Anyone else?

www.silveradosierra.com

 

[strutaeng]

Found some interesting info on hptuners forum from Robert at Transgo...

"As for making it not slip the converter clutch in 5th and 6th that's mostly only good for aftermarket converter that don't use the GM woven carbon lining and so prone to shudder. The carbon woven lining is very brittle and designed to slip without wearing out, but it is super brittle . the extra pressure required to make it not slip and the increase rate of apply is ******* it and it often will crack and lose chunks of it causing the TCC to start slipping after many thousandths of mile with this modification. Eliminating lock up in 1-2-3-4 is not going to hurt anything, but I would not recommend increasing the pressure to stop it from slipping the 20 or so RPM factory programing does."

Little more info here...

2010 Tahoe with 6L80, tune for longevity and towing

I have a 2010 Tahoe 5.3 (LMG) with the HD trailering package (8200lb rating) and occasionally tow a 7500lb trailer. It has 170k miles and is currently running and shifting well. I recently purchased an MPVI3 for this vehicle and want to do the following: -Disable AFM -Disable flex fuel. I only...

forum.hptuners.com

Thanks for sharing! I'll read it in more detail later.

So I think he's saying in his opinion eliminating the TCC slippage doesn't hurt, but don't mess around with pressures and such on a high mileage vehicle in OP's case? And doesn't do anything to prolong the life of the original torque converter clutch, but there's better shift feel? Umm...

We have a low mileage family van with the 6L90e, and I was going to buy the HP credits to eliminate the TCC slippage this year, "just 'cause everyone recommends that"... luckily it doesn't have DOD AFM stuff...

My wife drives that van, every now then I'll drive it if we are all going somewhere. I honestly still prefer my 'ol suburban or other trucks with the ancient 4L80e

BTW, my buddy suggested I join the HP Tuners forum. How is it there? I'm not much of a "Tooner" though. IDK

 

[Marky Dissod]

my buddy suggested I join the HP Tuners forum. How is it there? I'm not much of a "Tooner" though.

Since the forum is run by HPTuners, some tuning subjects you can't discuss, some only after taking a course or some humbuggery ...
They wub acronyms and jargon, moreso than normal
You know how most doctors tend to say
Non-ST-Elevation Myocardial Infarction / NSTEMI
before they say
heart attack?
It's like that over there too.

 

[mikez71]

Well the hptuners board seems to deal with mostly performance tuning, removing MAF, programming segment swaps and so on. I just scour it for general gen 4 and 6l80 tidbits.

Transgo Robert seems to indicate that zeroing slip on stock tcc will require a bump from ~40psi to ~60psi, and that the way the factory setup was designed, its just not meant to fully lock. Conversely the aftermarket clutches would prefer to fully lock or they may shudder.

Also something about a PR valve (pressure regulator?) wearing out being the main issue that kills them. Some photos in that linked thread, but havent been able to look at it yet..

Personally, I like the locked feel, but eliminated it in 1-3, felt 4th was worth it for slow cruise and really just get tired tweaking shift points and trying to get the corresponding lockup map in sync. I did notice some tuning changes in the 2015 tahoe with the 6l80 (like it always is locked in higher gears, flat graph. its on at x speed and off at y speed. ) Sometimes the tcc lock speed is below the shift speed, so it must lock right away, whereas my 2012 usually has the tcc lock 2mph or so after the shift. I also heard somewhere that the 2015-2018 6l80 does not last as long as the previous years...

 

[swathdiver]

I also heard somewhere that the 2015-2018 6l80 does not last as long as the previous years...

That's because of the thermostat they have. Runs hot all the time, converter flexes and clutch material breaks off and runs through entire trans.

 

[mikez71]

Only thing is, many of us don't have an aux cooler and the radiator would tend to heat the fluid higher than the thermostat temp. Unless of course the thermostat sticks..

Little update, Transgo Rob feels like the later 6l80's seem to last a little longer than previous gens. I'm sure nobody has complete numbers, and that was his impression (which I'm sure can depend on the area, shop, number of newer vs older vehicles etc.) He also does not think the tune differences affect anything other than fuel economy..

Here are Robert's photos of the PR valve wear since you need to login to view pictures.

 

[Just Fishing]

I'll note that I tried disabling the tcc lockup in the lower gears, it made it drive better, more pep.
but my mileage went to shit, and my transmission fluid temps went up a bit!

I made some minor changes but kept the lockup in the end.
Now tow mode I had more fun and got rid of most of the lockup, but kept it in 6th.
That allows me to switch back and forth while watching the temps.

My converter also isn't stock, it's a double disk circle d unit with a slightly higher stall.

I also reduced overall allowed slippage by 50%

 

[89Suburban]

@NickTransmissions

 

[Marky Dissod]

Torque Converter Clutch lockup improves MpG and lowers ATF temps when the vehicle is being driven gently ... up to a point ...

Prior to '95, TCC locking was On or Off, which came with little gentle thumps - enthusiasts don't mind them, pensioners do though (?).
GM started Pulse Width Modulating the TCC since '95 to try to satisfy NVH targets, sacrificing some of the TCC's durability / longevity.

I made some minor changes but kept the lockup in the end.

How much of it did you keep, vs how much you did not?