I am new to the forum and wanted to share my GM valve body issue story.
There are thousands of GM 10 speed vehicles sitting at dealerships.
Maybe this will help someone with the same 10 speed issue.
2023 Duramax 3.0 liter diesel.
I have had (2) different trucks with the same issue.
The dealership kept my first truck for over 4 months last year. Dealer installed the new valve body. It lasted 1500 miles and broke down again.
I traded the broken truck for an identical used truck they had on the lot.
After 21,000 miles the 2nd truck went into limp mode and was stuck in 5th gear.
Dealer told me the valve body was on back order and there were 13 trucks sitting on the lot in front of me with the same issue.
Lemon law would not help me due to miles accumulated.
I could not have another truck sit on their lot collecting dust and bird droppings for months on end.
The dealership had no loaner vehicles available for me to drive.
The dealership could not confirm that GM would reimburse me for a rental car that would cost thousands of dollars.
This is my work truck and I need it to do my job and make a living.
Let me say I really like my truck and have it set up to work out of.
I get reimbursed for my mileage at work so I need to get good fuel economy.
I don’t want a Tundra that gets 15 miles per gallon.
I can’t bring myself to buy a Ford or a Dodge, they have their own issues.
I can’t haul the truck to another dealership and trade in a truck that is stuck in limp mode. If I did, what would the trade value be?
I almost bought a 2025 2500 Denali 6.6 until I learned that I would spend over $100k for a truck that has the same issues.
Yes, the so called Allison transmission valve body is failing also.
So I did some research.
The valve bodies that GM sends as a replacement has not been updated.
The are sending out the same faulty part with no regard.
Loyal customers waiting months for another faulty part to be delivered and installed.
GM is doing nothing to fix this issue. It is a bandaid at best.
There is a company that has developed a fix for the valve body issues.
Next Gen Drivetrain has developed a kit that fixes the faulty valve body.
I spoke with Next Gen and they sell this kit to a few different transmission shops that they recommend.
I decided to take matters into my own hands because I wanted my truck back.
I had a rollback pick my truck up at the dealership and bring it to my house.
I jacked the truck up and removed the valve body.
I shipped the valve body to No Zone Transmission to have them install the kit.
No Zone Transmission installed the kit.
They shipped it back to me with a deep pan from PPE that holds an extra 2.5 quarts of fluid.
I installed the upgraded / rebuilt valve body and the new pan. Also added a thermal bypass valve from PPE.
My truck is fixed! Shifts perfectly and trans fluid temps are 60 degrees cooler than before.
So, it cost me around $2500.00 out of pocket.
I know what you are thinking. My truck is under warranty and I spent $2500.00 out of pocket?
But, I have my truck back and trans is shifting great.
I had no confidence that GM would send a valve body that would last.
No Zone Transmission was great to deal with and very helpful.
They install the kits for the 1500s, 2500s and 3500 10 speed transmissions.
Hope this post may help someone.
There are thousands of GM 10 speed vehicles sitting at dealerships.
Maybe this will help someone with the same 10 speed issue.
2023 Duramax 3.0 liter diesel.
I have had (2) different trucks with the same issue.
The dealership kept my first truck for over 4 months last year. Dealer installed the new valve body. It lasted 1500 miles and broke down again.
I traded the broken truck for an identical used truck they had on the lot.
After 21,000 miles the 2nd truck went into limp mode and was stuck in 5th gear.
Dealer told me the valve body was on back order and there were 13 trucks sitting on the lot in front of me with the same issue.
Lemon law would not help me due to miles accumulated.
I could not have another truck sit on their lot collecting dust and bird droppings for months on end.
The dealership had no loaner vehicles available for me to drive.
The dealership could not confirm that GM would reimburse me for a rental car that would cost thousands of dollars.
This is my work truck and I need it to do my job and make a living.
Let me say I really like my truck and have it set up to work out of.
I get reimbursed for my mileage at work so I need to get good fuel economy.
I don’t want a Tundra that gets 15 miles per gallon.
I can’t bring myself to buy a Ford or a Dodge, they have their own issues.
I can’t haul the truck to another dealership and trade in a truck that is stuck in limp mode. If I did, what would the trade value be?
I almost bought a 2025 2500 Denali 6.6 until I learned that I would spend over $100k for a truck that has the same issues.
Yes, the so called Allison transmission valve body is failing also.
So I did some research.
The valve bodies that GM sends as a replacement has not been updated.
The are sending out the same faulty part with no regard.
Loyal customers waiting months for another faulty part to be delivered and installed.
GM is doing nothing to fix this issue. It is a bandaid at best.
There is a company that has developed a fix for the valve body issues.
Next Gen Drivetrain has developed a kit that fixes the faulty valve body.
I spoke with Next Gen and they sell this kit to a few different transmission shops that they recommend.
I decided to take matters into my own hands because I wanted my truck back.
I had a rollback pick my truck up at the dealership and bring it to my house.
I jacked the truck up and removed the valve body.
I shipped the valve body to No Zone Transmission to have them install the kit.
No Zone Transmission installed the kit.
They shipped it back to me with a deep pan from PPE that holds an extra 2.5 quarts of fluid.
I installed the upgraded / rebuilt valve body and the new pan. Also added a thermal bypass valve from PPE.
My truck is fixed! Shifts perfectly and trans fluid temps are 60 degrees cooler than before.
So, it cost me around $2500.00 out of pocket.
I know what you are thinking. My truck is under warranty and I spent $2500.00 out of pocket?
But, I have my truck back and trans is shifting great.
I had no confidence that GM would send a valve body that would last.
No Zone Transmission was great to deal with and very helpful.
They install the kits for the 1500s, 2500s and 3500 10 speed transmissions.
Hope this post may help someone.
