GM Trucks Gen. 3 10L60/80/90 Service Valve Body: Changes & Identification

​​​​​​​A new service valve body is now available for GM 10L60/80/90 and is deemed a Generation 3. This valve body came in to existence June 19, 2025, and is currently available under two part numbers: 24071206 for 3.0L Diesel applications and 24071207 for 5.3L and 6.2L gas in GM trucks. These two part numbers only fit ETRS models with electronic park control. This Gen 3. valve body has been redesigned to help prevent the wheel lockup conditions in trucks that were under recent GM Safety Recalls N242480630 and N242454440. This valve body looks quite different than the Gen. 2 that started into production in 2019, but it will back service these vehicles even though it doesn’t look the same. Note: it is important when replacing a valve body to be sure that you verify fitment with the VIN.

The following information identifies the changes in this valve body and the locations for small parts including checkballs, relief valves, damper pistons, etc. There is also valve identification, as components have changed.

Figure 1 Shows a Gen. 2 valve body and the solenoid locations. Notice the Gen. 2 has a lower casting where the default disable solenoid is located.

Figure 1 - Gen. 2 Valve Body (Non-ETRS)

Figures 2 and 3 show the Gen. 3 and the change in the solenoid location for the TCC to the case side of the valve body. This is the easiest way to identify the Gen. 3. Notice also the lower casting has been eliminated and the default disable solenoid is now mounted to the lower cover plate.

Figure 2 - Gen. 3 Valve Body (ETRS)

Figure 3 - Gen. 3 Valve Body, Case Side

Figure 4 shows a closeup of the new manifold for the default disable solenoid and also the small parts locations.

Figure 4 - Gen. 3 Lower Valve Body, Lower Side Small Parts Locations

Figure 5 shows the lower valve body upper side with the clutch control solenoids and clutch regulator valves removed. Note: the labels of these valves, A through F, are cast into the lower valve body for ID purposes.

Figure 5 - Gen. 3 Lower Valve Body, Upper Side Clutch Regulator Valve Locations

Figure 6 - Gen. 3 Lower Valve Body Control Valve Locations

Figure 7 - Gen. 3 Lower Valve Body, Upper Side Small Parts Locations

Figure 8 - Gen. 3 Separator Plate

Figure 9 Shows the upper valve body right side valve trains and also the upper valve. Note: the design of the pressure regulator valve went the direction of the 10L1000. Also notice that there is only one feed limit valve. This valve does limit solenoid feed to the default disable solenoid in a similar manner as the previous version and it feeds the A and B boost balls. The feed limit high valve train — for which Sonnax offers drop-in and oversized repair valves — has been eliminated. With no feed limit high valve, there is no need for the two boost balls for the C and F clutches like the Gen. 2 version had.

Figure 9 - Gen. 3 Upper Valve Body, Right Side Valve Locations

Figure 10 shows the upper valve body left side. There is a default enable, default select and a lube control valve. The default valves have a redesigned oil circuit that prevents the wheel lockup scenario if solenoid feed to the default disable solenoid is low, which is what the cause for that condition was on the previous Gen. 2 version.

Figure 10 - Gen. 3 Upper Valve Body, Left Side Valve Locations

Jim Dial is a Sonnax product line manager. He is a member of the Sonnax TASC Force (Technical Automotive Specialties Committee), a group of recognized industry technical specialists, transmission rebuilders and Sonnax Transmission Company technicians.