6L80E out at 81k

[Rat407]

Seems I have been the lucky one to have our transmission go out in our 2016 Suburban. Been using AMSOIL ATL fluid since 5k miles and changed out filter and fluid again at 45k. Seems the issue is pointed to AFM causing issues with the TC and it trashing the fluid.

I just hope I caught it before it caused major damage. Shop that has been in business over 34 years here said they rebuild them all the time. Use upgraded VB and TC. Total out the door would be $3,600. Only problem is a three week wait.

To me when AFM is active, I can feel a small vibration and have been since new. This is on all the GM vehicles I have drove with AFM so it isn't just ours. I would think that the frequency harmonics come into play and trash over time. Just like any vibration can. That is my thought on this.

 

[tyman]

That's why disabling AFM as soon as one can is important. AFM is trash.

 

[oldcodger]

I am dumb, AFM?

 

[BlueOvalFitter]

That's why disabling AFM as soon as one can is important. AFM is trash.

What is AFM, AUTOMATIC ____________ MODE?

 

[Rand]

.. active fuel management.. deactivates some cylinders.
Same idea as honda VCM but not implemented the same.

 

[tyman]

What is AFM, AUTOMATIC ____________ MODE?

Automatic effing terrible mode

 

[tyman]

I am dumb, AFM?

What is AFM/DFM? An In-Depth Look

Our Marketing Brand Manager takes an in-depth look at Active and Dynamic Fuel Management

www.rangetechnology.com

 

[blufeb95]

I thought there were more problems than just AFM that causes the 6L80E converter failures, like that PWM should be disabled for the TCC apply and some other tuning is recommended because the default GM program on the transmission loves to slip the TCC and burn it up.

 

[Snagglefoot]

If anyone is interested, here are two versions of the delete kit from SDPC.
The first version is basic and it assumes you’ll source your own cam and liters. The second version adds a new cam and lifters.

 

[Tman220]

One of the reasons I bought a silverado last year was the fact that due to the chip shortage it was not factory equipped with AFM.

I follow Precision Transmission on YT, they rebuild a lot of 6L80's and the failure mode does seem to be pretty consistent. The torque converter starts to fail and the system is flooded with trash, this takes out the pump and if it keeps driving will plug the filter and start burning clutches.
Occasionally they seem to find a cracked piston or a broken wave plate but the Torque converter seems to be the culprit.

I bought this truck hoping that without AFM I would get more miles out of the transmission, less chance of a failed AFM lifter (apparently they're still equipped with AFM lifters even when that option is omitted on the vehicle) I'm hoping that plan work out but if I find out the TC's are trash even without AFM I will gladly drop the transmission on a brand new truck to replace the converter even if I shouldn't have to.

 

[Tman220]

If anyone is interested, here are two versions of the delete kit from SDPC.
The first version is basic and it assumes you’ll source your own cam and liters. The second version adds a new cam and lifters.

View attachment 96887View attachment 96888

A quick note for the above links. That is for an LS engine which is different than the LT based engine in a 2016 suburban. The above kit will work in 5.3's with the last year being 2013. The new engines became available with the redesign for 2014.
I believe there may even be changes between the earlier L83 5.3's and the later L82's and L84 5.3's when it comes to an AFM delete kit, there were changes made to the block, water pump location and a few other things so keep an eye on those things if anyone is looking for a kit.

 

[Tahoe4Life]

I just hope I caught it before it caused major damage. Shop that has been in business over 34 years here said they rebuild them all the time. Use upgraded VB and TC. Total out the door would be $3,600. Only problem is a three week wait.

To me when AFM is active, I can feel a small vibration and have been since new. This is on all the GM vehicles I have drove with AFM so it isn't just ours. I would think that the frequency harmonics come into play and trash over time. Just like any vibration can. That is my thought on this.

3600 bucks is a excellent price. My GMC dealer charges 5400 bucks out the door.

Mine went out [2016 5.3 Tahoe] at 124K miles. My extended warranty was almost up [only 500 miles left] when mine went belly up so it only costed me 100 bucks thankfully. Took them a week to install it as the warranty company had to come out to inspect it first to give the green light to replace it then the dealer had to order it. Thankfully the extended warranty covered half of my rental car expenses.

Was also told by my dealer the transmission temperature was set to high from the factory on the 2015+Tahoe-Yukon-Suburban. The GMC dealer lowered the temperature after installing the new one.

AFM is still enabled but seriously thinking of having Black Bear Performance giving it a tune as they will tune out the AFM. I have no plans on selling my Hoe anytime soon as it is paid for and it is overall good on fuel [around 23-25 MPG] out on the highway on 87 octane fuel.
BTW never noticed any vibration.

The warranty on the rebuilt transmission is 3 years or 100K miles. Was told by the dealer to change out the fluid at 50K miles. Before the transmission went out I changed out the fluid every 45K miles. The dealer did the changes.

 

[Jim_Truett]

The calibration commands TC slip in both standard and AFM modes to help with NVH reduction. Disabling AFM is a start, but until you zero out all commanded slip tables and increase TC apply rise you are not eliminating the issue.

 

[Snagglefoot]

A quick note for the above links. That is for an LS engine which is different than the LT based engine in a 2016 suburban. The above kit will work in 5.3's with the last year being 2013. The new engines became available with the redesign for 2014.
I believe there may even be changes between the earlier L83 5.3's and the later L82's and L84 5.3's when it comes to an AFM delete kit, there were changes made to the block, water pump location and a few other things so keep an eye on those things if anyone is looking for a kit.

A person can do their own homework. Get a hold of Scoggin Dickie if anyone is interested. Here’s a kit for later models.

 

[Jim_Truett]

Typical standard mode TCC commanded slip table. Double these numbers for AFM mode. My Yukon would apply the TCC in second through sixth gears. I disabled TCC lockup in 2nd and 3rd, but have lockup enabled 4-6 to keep the trans cool when I tow.

 

[Rat407]

Waiting on Black Bear Performance to update my tune. Also the dealer here wanted $6,000 to replace with a reman unit. It's my understanding that the remain is the same, no upgraded parts. Which makes sense, no need for GM to spend more than what they have to.

 

[Tahoe4Life]

Waiting on Black Bear Performance to update my tune. Also the dealer here wanted $6,000 to replace with a reman unit. It's my understanding that the remain is the same, no upgraded parts. Which makes sense, no need for GM to spend more than what they have to.

How often does Black Bear have to update the tune?

 

[Rat407]

How often does Black Bear have to update the tune?

They don't unless you make changes to the vehicle. I'm waiting for them to deactivate my AFM. From what I have read, that is one part to the problem with these transmissions going out.

 

[clinebarger]

The TCC Tables really need to be custom tuned, Unfortunately.......Not many professional "Tuners" are proficient at transmission tuning.

If you want to buy your own HP-Tuners.....I can walk you through setting up the TCC Tables to get the most life out of the TC Clutch Lining.

 

[Rat407]

The TCC Tables really need to be custom tuned, Unfortunately.......Not many professional "Tuners" are proficient at transmission tuning.

If you want to buy your own HP-Tuners.....I can walk you through setting up the TCC Tables to get the most life out of the TC Clutch Lining.

For now the funds don't allow much. It is all we can do to pay for the repair.