[FlukeSS]

Originally Posted by tortilla-flats

Help me understand what what I'm missing. If this is the result of an upgraded valve body, why aren't the 2023-2024 models impacted? Is the valve body further upgraded? v3?

There are 3 types of A10's

1. Allison A10 (Trucks normally as far as I know) (Also GM paid to license the name Allison otherwise its the same A10 transmission)
2. Generation 1 A10's (Our cars / Ford 10R60/80/90)
3. Generation 2 A10's (Also our cars)

Generation 1 A10's do not have the problem.

Only Allison and Gen 2 A10's have the issue. GM changed the valve body on Gen 2, and now its ef'd.

Next Gen DriveTrain developed a fix for this valve body. GM refuses to fix the issue to push people out of warranty. When Dealerships/GM do fix these issues they replace the defective valve body with the SAME defective valve body.

And Some 2023 and 2024's are affected by this but no official annoucement from GM. More so if they use the Gen 2 A10.

You'll want to read Next Gen Drivetrains article about it as they did extensive testing about it and developed a fix for it. Even Chevy Dealers are buying this fix at their cost from Next Gen Drivetrains to avoid buying the cars back under lemon law.

Also, we discovered that the Ford 10 Speed (this transmissions fraternal twin) did NOT have this problem. This means that the problem is logically caused by something the General Motors variant has that the Ford variant does not.

Further, we discovered that customers who installed our Project Carbon® General Motors 10-Speed Valve Body Upgrade Kit almost always fixed the problem, and that customers who installed our re-engineered Project Carbon® General Motors 10-Speed Valve Body always fixed the problem.

This means that the problem is clearly caused by a hydro-mechanical difference between a Ford and General Motors valve body. But, we discovered something else that was even more alarming. Are you ready for this?

There are two generations of the 10 speed General Motors transmissions, but only one type of the 10 speed Allison which is most similar to the later generation of the 10 speed General Motors unit. Why is this important?

We have zero recorded events of the first generation of the valve body having this symptom. The first generation of this valve body is almost identical to the Ford 10R80. This helped us narrow it down even further because we now know that the problem is something that was changed between the first generation and second generation 10 speed General Motors transmission.

Also, we know that the problem is a part that is mutual in design between the Allison variation of this transmission and the General Motors variation of the transmission. At this point, there are only so many parts remaining.

Lastly and perhaps most importantly, the problem becomes more likely as the transmission ages, implying it’s caused by a component wearing out or degenerating rather than a spontaneous electronic failure.

So what ultimately was the problem? A combination of crossleaks in the valve body that become worse over time can trigger the transmission to apply a fourth clutch pack erroneously in some of the higher gears, causing a bind-up condition that locks the output shaft of the transmission and subsequently the rear axle.

https://nextgendiesel.com/blogs/tran...ow-we-fixed-it