GM has recently issued a technical service bulletin referred to as Customer Satisfaction Program N232427051. As it happens, a number of 2023 and 2024 model year Corvette vehicles have been produced with improperly torqued transmission fasteners. General Motors doesn't mention the suspect production dates, and – worse still – does not mention which Corvette versions are affected.
The aforementioned technical service bulletin lists regular production order codes M1L and M1M for the suspect dual-clutch transaxles, with said codes referring to the Stingray and Z06 transmissions. The Corvette Z06's eight-speed box is also listed with T0F and T0G, which refer to the Carbon Flash- and the Visible Carbon-finish aerodynamic packages.
Regardless of mileage and the vehicle's age, dealers are required to replace said transmissions at no charge to the customers. The list of parts required for the operation includes the dual-clutch transaxle, coolant, an exhaust manifold pipe seal, the catalytic converter gasket, two wheel drive shaft nuts and two wheel drive shaft washers, six wheel drive shaft retainer assemblies, four air conditioning compressor hose seals, and four rear cradle bolts.
The labor time for transmission replacement is 14.2 hours for the Z06 Coupe, 17.3 hours for the Z06 Convertible with either aerodynamic package, or 14.4 hours for the Stingray Convertible. A further 1.2 hours are required to recharge the A/C system.
General Motors clearly states that any vehicle entering dealer inventory or the dealer's service facility has to be remedied before selling or releasing the vehicle to the rightful owner. The program runs through May 31 of 2026, meaning that Corvette Stingray Convertible and Corvette Z06 owners have a little over a year to make an appointment to replace the eight-speed transaxle.
Photo: Tremec
Supplied by Tremec, the TR-9080 was introduced in 2019 by the 2020 model year Corvette Stingray. Also used by Maserati in the carbon-tubbed MC20 that famously weighs more than the aluminum-intensive Ferrari 296, the TR-9080 comes with either a mechanical limited-slip differential or an electronic limited-slip differential. Topped up with Fucks Titan EG FFL-4 transmission fluid, the quick-shifting tranny weighs anything between 148.5 and 150.5 kilos (327.4 to 331.8 pounds).
The fill volume is 11 liters (11.6 quarts), and Tremec recommends a further 2 liters (2.1 quarts) for extended track use. Back in September 2019, the initial version of the TR-9080 was rated at 800 Nm or 590 pound-feet of torque. Not long now, General Motors will exceed this figure with the long-awaited return of the ZR1, which levels up on the high-revving Z06 with a couple of turbochargers.
Estimated to make 800-plus horsepower at full chatter, the LT7 engine is a completely different animal from the LT5 of the C7-generation ZR1. A dual-overhead-cammed mill rather than a small block, the LT7 is also believed to include AFM fuel-saving technology. This, in turn, suggests that GM switched to a cross-plane crankshaft as opposed to a flat-plane unit for the LT6 in the Z06.
Teased at the beginning of April 2024, the C8-generation ZR1 will be revealed this coming summer. Its dual-clutch box is known as the M1K, whereas the E-Ray uses the MLH version.
After a 1:43 scale model of a Ferrari 250 GTO sparked Mircea's interest for cars when he was a kid, an early internship at Top Gear sealed his career path. He's most interested in muscle cars and American trucks, but he takes a passing interest in quirky kei cars as well. Full profile
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