Chevrolet’s 2020 Silverado High Country is offered with a choice of three engines – two gasoline and one diesel – mated to one of two automatic transmissions – an eight-speed or a ten-speed. However, one particular configuration that was previously equipped with the ten-speed will now be equipped with the eight-speed instead.
Specifically, the 2020 Silverado 1500 High Country 4WD Short Bed model with the 5.3L V8 L84 engine featured the ten-speed automatic transmission since the beginning of the model year. However, GM Authority has exclusively learned that starting with vehicles ordered in July, this configuration will get the eight-speed unit instead, and the change will remain in effect through the end of the 2020 model year.
The process behind the change is also worthy of mention: dealers will continue placing orders for the trucks with the 10-speed automatic transmission, but GM will manually change the order to the 8-speed. As a result of the change, GM will provide a $200 credit on the vehicle invoice as well as on the window sticker. The change has yet to be reflected on any public-facing materials as of this writing.
When asked for a statement by GM Authority, Chevrolet declined to comment on the change.
However, sources have since told us that the 2020 Silverado High Country 4WD Short Bed model was previously limited in availability due to a constraint with a component associated with the ten-speed automatic gearbox in the 4WD Short Bed configuration. Since no solution currently exists to resolve this constraint, GM made the decision to replace the ten-speed transmission with the eight-speed.
Meanwhile, the optional 6.2L V8 L87 gasoline and 3.0L I6 LM2 turbo-diesel Duramax engines will continue being mated to the ten-speed transmission in the 2020 Silverado High Country, regardless of bed or drivetrain configuration. Additionally, 2WD Silverado High Country models powered with the 5.3L V8 L84 engine will continue shipping with the 8-speed automatic.
|Crew Cab||Short Bed||5.3L V8 L84 with DFM (gasoline)||2WD||8-speed auto|
|Crew Cab||Short Bed||3.0L I6 LM2 Duramax (diesel)||2WD||10-speed auto|
|Crew Cab||Short Bed||5.3L V8 L84 with DFM (gasoline)||4WD||10-speed auto, replaced with 8-speed auto in July 2020|
|Crew Cab||Short Bed||6.2L V8 L87 with DFM (gasoline)||4WD||10-speed auto|
|Crew Cab||Short Bed||3.0L I6 LM2 Duramax (diesel)||4WD||10-speed auto|
|Crew Cab||Standard Bed||5.3L V8 L84 with DFM (gasoline)||2WD||8-speed auto|
|Crew Cab||Standard Bed||5.3L V8 L84 with DFM (gasoline)||4WD||10-speed auto|
|Crew Cab||Standard Bed||6.2L V8 L87 with DFM (gasoline)||4WD||10-speed auto|
|Crew Cab||Standard Bed||3.0L I6 LM2 Duramax (diesel)||4WD||10-speed auto|
The GM Hydra-Matic eight-speed automatic transmission has been the subject of many complaints, mostly surrounding erratic shifting behavior and lackluster feel. GM issued a Technical Service Bulletin (TSB) to address the issues, though – based on comments from existing owners – the success of the fix appears to be hit-or-miss. A class-action lawsuit surrounding the issues with the transmission was filed in April of 2019.
By comparison, the GM 10-speed automatic transmission, which is newer than the 8-speed, does not appear to be suffering from these issues.