Wear in the main pressure regulator bore and on the outboard spool area of the valve is common in listed GM and Ford 10-speed RWD transmissions. This wear minimizes line pressure control, resulting in delayed shift engagement, poor shift quality and burnt clutches.
Reconditioning the bore and installing Sonnax oversized main pressure regulator valve kit 105740-20K eliminates the leakage of line pressure signal oil to exhaust with the incorporation of an extended front valve spool. This valve spool is 270% longer than the OE spool, allowing for better sealing contact and a more stable operating valve. The O-ringed end plug provides a positive seal and prevents critical signal fluid from leaking to exhaust. Both of these Sonnax features ensure your units will have proper line pressure control through all drive ranges.