Second 6l80 trans died today

[2015 High Miler]

I'm on my second GM transmission.  The first one died at 122,000 and the second has died at 225,000. Very little trailering, its been though the gears a few times but it has not been beat on IMO. While driving to DFW today, about 70 miles from home, it started to shudder and jump gears with no warning. I made it to work and then drove about 10 miles to where I am staying and it was very iffy if I would make it. 

 

Not sure what to do at this point.  Does anyone know of a good rebuilder/replacement if DFW/Central Texas area?  I'd like to fix it one last time and be done.  Should have done that last time but GM paid for half of it then.  Need a trans and converter and install. 

 

This one has had a tune on it to help with the converter issues but I guess I was too late to save it.  

[Snowcamo]

Try these guys. Transmission rebuild. ask them to use the Sonnax zip kit. That will correct the issues this transmission has.

[shakenfake]

If you live near the Austin area or go there for work you can check out A+ Transmissions. My 4L60e lasted fantastically behind my 6.0

It is some shops owned by my uncles. They do good work and know GM pretty damn well.

[2015 High Miler]

I found a shop in Garland that is going to fix and update all of the weak points. 
 

Price point was very fair. Imo. 
 

im hoping it’s as good as the price. With the extended mileage on this truck, I’d get nothing for trade in so I’ll fix it and keep driving or make as an extra vehicle.  It’s still in great shape as it’s always been a highway vehicle. Waco to DFW, Houston, Austin and San Antonio. 
 

I‘ll share where once I get It back. 
 

thanks for the help 

[Nestor Romero]

You were able to get  GM to cover half of it the first time at 122K miles?

 

 

I was under the impression that the powertrain warranty was only good for 5 years/60K miles.

[2018GMC]

2007 - 2015 5yr 100k miles powertrain
2016+ 5yr 60k miles powertrain

[2018GMC]

 

[2015 High Miler]

4 hours ago, Nestor Romero said:

You were able to get  GM to cover half of it the first time at 122K miles?

 

 

I was under the impression that the powertrain warranty was only good for 5 years/60K miles.

I was fortunate. It was a goodwill gesture from the dealer to get it covered. 
 

 

[elcamino]

I thought Dexon VI was the ATF to end all ATF's, no transmission should ever fail because GM says DEXRON-VI is far superior.

[newdude]

On 3/7/2022 at 11:02 PM, 2015 High Miler said:

I'm on my second GM transmission.  The first one died at 122,000 and the second has died at 225,000. Very little trailering, its been though the gears a few times but it has not been beat on IMO. While driving to DFW today, about 70 miles from home, it started to shudder and jump gears with no warning. I made it to work and then drove about 10 miles to where I am staying and it was very iffy if I would make it. 

 

Not sure what to do at this point.  Does anyone know of a good rebuilder/replacement if DFW/Central Texas area?  I'd like to fix it one last time and be done.  Should have done that last time but GM paid for half of it then.  Need a trans and converter and install. 

 

This one has had a tune on it to help with the converter issues but I guess I was too late to save it.  

 

Did you ever flip your trans thermostat after the first trans was put in it?  Its GM's high operating temps that has lead to many of the failures, plus the converter design they chose.  If you rebuild or replace, flip or SureCool mod it.  

 

38 minutes ago, elcamino said:

I thought Dexon VI was the ATF to end all ATF's, no transmission should ever fail because GM says DEXRON-VI is far superior.

 

Its not the fluid that is the problem.  Its the heat and converter design.  6L's can fail on ANY fluid.  

Edited March 9, 2022 by newdude

[elcamino]

Quote

Its not the fluid that is the problem.  Its the heat and converter design.  6L's can fail on ANY fluid.  

No, the fluid is BIG part if the problem.  Good fluid would tolerate the heat.  Dexron is a minimum quality standard and while it plays a role, its also is an incentive for licensed ATF's to meet the minimum standard and no more.  Its designed to last the warranty period, after that, its the owners problem.  GM does not want your transmission to last forever, they want to sell you a new vehicle.

 

 

Edited March 9, 2022 by elcamino

[newdude]

4 minutes ago, elcamino said:

No, the fluid is BIG part if the problem.  Good fluid would tolerate the heat.  Dexron is a minimum quality standard and while it plays a role, its also is an incentive for licensed ATF's to meet the minimum standard and no more.  Its designed to last the warranty period, after that, its the owners problem.  GM does not want your transmission to last forever, they want to sell you a new vehicle.

 

 

 

 

Heat kills ANY fluid.  

[Snowcamo]

56 minutes ago, elcamino said:

I thought Dexon VI was the ATF to end all ATF's, no transmission should ever fail because GM says DEXRON-VI is far superior.

Note all the parts in the sonnax zip kit I listed. 

 

It is just a piss poor design. As all other consumable good these days it was built with low cost in mind. Straight bull. At one point you could buy directly from sonnax. There were/ are more parts that are to be considered upgrades that correct the bs in these gm trans. 

[elcamino]

1 hour ago, newdude said:

 

 

Heat kills ANY fluid.  

No, heat kills most fluids.  100% Synthetic's can withstand much higher temperatures, 300ºF++. There are very few 100% synthetic ATF's to choose from though.  OEM spec  encourages producers to go no farther than meeting the minimum standard.  Few very oil companies are willing to spend more time and money to create higher levels of protection when all they have to do it meet a minimum standard.  Prime example is all the problems GM is having in recent years with the 8-sp trans and all the different iterations of ATF that they are calling for in service bulletins.  They had to go to Mobil 1 to develop a completely new GTL (group III) ATF because their in-house low bid brand was a problem.  While the engineers set standards, the bean counters seek out the lowest price suppliers and with low prices, often comes lower quality.  Good enough. 

[diyer2]

So changing the fluid more frequently in a 6L80E will help?