Trans problems

[tig1]

My son owns a 2017 GMC Yukon and the trans has had a clunk at low speeds(like in a parking lot) since it was nearly new. This time the dealer has pulled the trans and has it torn down and are replacing several parts. The transmission tech told my son this is the 31st one he has had to rebuild so apparently this is a ongoing problem in these type of vehicles. Has anyone else had this issue?

 

[eljefino]

How do we know it's the trans and not a u-joint?

 

[Kira]

Did the trannie tech mention what specifically was wrong with the 30 bad ones before your son's?

 

[14Accent]

Lots of issues with the 6L80. He's not alone.

 

[Lubener]

Originally Posted By: 14Accent

Lots of issues with the 6L80. He's not alone.

That model isn't the only GM gem with issues.

 

[demarpaint]

Originally Posted By: Lubener

Originally Posted By: 14Accent

Lots of issues with the 6L80. He's not alone.

That model isn't the only GM gem with issues.

So I've heard.

 

[Donald]

Maybe buy an extended warranty.

 

[PimTac]

Originally Posted By: Donald

Maybe buy an extended warranty.

I would push GovMo for an extended warranty. They must know there is an issue. Shouldn’t have to pay for one.

 

[Kira]

How do you push? "Gimme a double warranty or else I won't buy your vehicle"? ???

 

[Silverado12]

Look at the domestic parts content on GM trucks; the quality and QC has gone down accordingly.

 

[clinebarger]

Originally Posted By: 14Accent

Lots of issues with the 6L80. He's not alone.

GM has had 6L80E/6L90E issues ironed out since 2012. But.....Please elaborate. Not that a 2017 Yukon even has a 6L80E, It has a 8L90E.....Different unit altogether!

 

[tig1]

Originally Posted By: 14Accent

Lots of issues with the 6L80. He's not alone.

Because he has had it in the shop three times and this apparently is a common problem.

 

[tig1]

Originally Posted By: Kira

Did the trannie tech mention what specifically was wrong with the 30 bad ones before your son's?

The power valve was mentioned.

 

[clinebarger]

Originally Posted By: tig1

Originally Posted By: Kira

Did the trannie tech mention what specifically was wrong with the 30 bad ones before your son's?

The power valve was mentioned.

Must have a Holley Carburetor in that trans?? Or do you mean Boost Valve? Though that wouldn't cause a clunk.

 

[tig1]

Originally Posted By: clinebarger

Originally Posted By: tig1

Originally Posted By: Kira

Did the trannie tech mention what specifically was wrong with the 30 bad ones before your son's?

The power valve was mentioned.

Must have a Holley Carburetor in that trans?? Or do you mean Boost Valve? Though that wouldn't cause a clunk.

Thanks for the correction. I meant Valve body. Here is a link to a bad VB which can cause hard shifts. https://cartreatments.com/valve-body-functions-and-symptoms/

 

[irv]

Originally Posted By: tig1

Originally Posted By: 14Accent

Lots of issues with the 6L80. He's not alone.

Because he has had it in the shop three times and this apparently is a common problem.

You got that right. 25 pgs since 2014 and still going. http://www.gm-trucks.com/forums/topic/157944-transmissions-issuesproblems/

 

[tig1]

Originally Posted By: irv

Originally Posted By: tig1

Originally Posted By: 14Accent

Lots of issues with the 6L80. He's not alone.

Because he has had it in the shop three times and this apparently is a common problem.

You got that right. 25 pgs since 2014 and still going. http://www.gm-trucks.com/forums/topic/157944-transmissions-issuesproblems/

irv, Thanks, I'll send that on to my son.

 

[irv]

Originally Posted By: tig1

Originally Posted By: irv

Originally Posted By: tig1

Originally Posted By: 14Accent

Lots of issues with the 6L80. He's not alone.

Because he has had it in the shop three times and this apparently is a common problem.

You got that right. 25 pgs since 2014 and still going. http://www.gm-trucks.com/forums/topic/157944-transmissions-issuesproblems/

irv, Thanks, I'll send that on to my son.

No problem, and good luck to your son.

 

[SteveSRT8]

Originally Posted By: clinebarger

Originally Posted By: 14Accent

Lots of issues with the 6L80. He's not alone.

GM has had 6L80E/6L90E issues ironed out since 2012. But.....Please elaborate. Not that a 2017 Yukon even has a 6L80E, It has a 8L90E.....Different unit altogether!

It seems obvious that folks here do not understand how many of these units are out there. HUGE production numbers. And 30 units at a busy dealer isn't enough to be concerned about. My bet is they were mostly 8L90's. The 6L trans is in two of our trucks and it has been rock solid. There is some low speed turn clunking on the downshift which we traced to the stupid stability control system! It pulls throttle at the slightest sign of a corner! Great thread to bash in, though...

 

[tig1]

Originally Posted By: SteveSRT8

Originally Posted By: clinebarger

Originally Posted By: 14Accent

Lots of issues with the 6L80. He's not alone.

GM has had 6L80E/6L90E issues ironed out since 2012. But.....Please elaborate. Not that a 2017 Yukon even has a 6L80E, It has a 8L90E.....Different unit altogether!

It seems obvious that folks here do not understand how many of these units are out there. HUGE production numbers. And 30 units at a busy dealer isn't enough to be concerned about. My bet is they were mostly 8L90's. The 6L trans is in two of our trucks and it has been rock solid. There is some low speed turn clunking on the downshift which we traced to the stupid stability control system! It pulls throttle at the slightest sign of a corner! Great thread to bash in, though...

Sounds like the problem my son has with his trans. Clunking at low speed. Not good according to his dealer. There are about 4700 GMC and Chev dealers in the US alone. At 30 per we are talking about 141,000 units to date. +or-.