Sonnax 77777L-K Features:

Vehicles with a GM 200-4R, 700-R4, or 4L60-E transmission can experience 1-2 light throttle abrupt or bang shifts, especially when using the 093 Corvette or 553 2nd apply servo pistons. The traditional solution is to make the servo piston apply diameter smaller, however this limits the 2-4 band life. This shift problem can occur due to sleeve wear allowing torque signal and/or accumulator pressure leakage, or when the accumulator valve is too large for the application, resulting in too much pressure on the 2-4 band.

This valve train has multiple OE size variations, including B, A, N, M, L, K, and F. The size variations are clearly stamped with the letter on the aluminum sleeve. Most vehicles, depending upon the transmission/engine combination, can use either the M, L, or K version. However, these are not available unless scavenged from other valve bodies. Sonnax offers two replacement accumulator valve train kits: 77777M-K for the M (.341" valve diameter) and 77777L-K for the L (.330" valve diameter).