Quick-Fill Valve

The 3-4 shuttle valve used in previous valve bodies has been replaced by a 3-4 quick fill valve in the 42RE. The function of the new valve is faster engagement of the overdrive clutch during 3-4 upshifts.

The valve temporarily bypasses the clutch piston feed orifice at the start of a 3-4 upshift. This exposes a larger passage into the piston retainer resulting in a much faster clutch fill and apply sequence.

The valve does not bypass the regular clutch feed orifice throughout the 3-4 upshift. Instead, once a predetermined pressure develops within the clutch, the valve closes the bypass. Clutch fill is then completed through the regular feed orifice.