Description
Sonnax # 77777M-K
700R4 Accumulator Valve Train Assembly, #18C. For heavy vehicles with 3.08 to 3.42 ratios.
#18C. For heavy vehicles with 3.08 to 3.42 ratios. Use this one with taller than stock tires, and lower than stock gear ratios.
Vehicles with a 700R4 transmission can experience 1-2 light throttle abrupt or “bang” shifts, especially when using the Corvette or larger 2nd apply servo pistons. The current industry solution is to make the servo piston apply diameter smaller. This, however, limits the 2-4 band life. This shift problem commonly occurs when the accumulator valve is too large for the application, resulting in too much pressure on the 2-4 band. This valve train has 7 different OEM size variations: B, A, N, M, L, K, and F. They range from the largest valve diameter giving the firmest shift (B) to the smallest valve diameter giving the softest shift (F), respectively. 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. Each kit contains three springs of varying spring rates.
