May 25, 2017
In 2014, GM moved to Generation 3 on the 6T40 family, featuring a vastly different pump than previous generations. The pump moved to an off-axis, binary vane style design that reduces pump flow demands and torque requirements, aiding in better fuel economy. A lube on demand regulating valve has been added to the pump, allowing cooler/lube flow to double when converter feed is above 87psi. This highly active valve is a huge source of pump wear, opening a path for converter feed pressure to exhaust, resulting in converter apply issues, reduced line pressure and overheating.
Sonnax has developed a unique, patent-pending, drop-in solution that maintains the integrity of the OE design of double-flow at increased pressure, while mitigating any existing bore wear and preventing future pump casting degradation. Sonnax drop-in lube on demand valve kit 144510-19K reroutes fluid to a sleeved limit valve for proper cooler/lube flow and includes an O-ring to seal the path that previously allowed valuable converter feed pressure to exhaust.
Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.