August 21, 2013
GM 6L45, 6L50, 6L80 and 6L90 clutch boost valves provide feedback pressure to their respective clutch regulator valves, balancing the regulators to assist with apply and release of the associated clutch. Pressure control solenoid fluid acts on the boost valve to precisely control the amount of oil delivered to the balance end of the clutch regulator valve. Excess wear in boost valve bores can result in harsh shifts, slipping, burnt clutches, flares, codes, and delayed engagement. Reconditioning the bore and installing Sonnax oversized clutch boost valve 104740-01 restores the hydraulic control necessary for trouble-free shifting.
Proper operation of clutch boost valves depends on correct pressure being supplied by shift solenoids. If trouble is found with pressure supply to these solenoids, Sonnax offers oversized AFL valve 104740-12.
This valve is packaged individually, but can be used in any of three bore locations:
Sonnax valve body layouts provide a detailed overview of individual units making it quick and easy to determine what’s available for the specific valve body you’re working on. See all Sonnax valve body layouts.
Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected. Valve body casting is stamped with "lettered" locations on the far side of the core; when testing "B" or "F" location, block exhaust hole on far side of core.