The OE valve has a fixed flow rate, while C1 clutch pressure leaks to exhaust.
The Sonnax kit includes a PTFE seal to prevent C1 oil loss to exhaust. The new valve changes the fixed flow rate to a regulated flow rate.
The OE C1 clutch control valve has a fixed flow rate and no seal at the large spool to prevent hot fluid loss. The Sonnax updated valve 37000-05K controls the fill and exhaust rate of the C1 clutch as well as reducing loss at the valve bore. The regulation contour of the Sonnax valve provides a controlled fill to reduce harsh engagements common to cold weather, long sit or reverse to forward abuse conditions. Controlling the flow rate reduces wear on the C1 clutch hub. Once the valve is open, the C1 flow is increased over OE to overcome fluid loss at the drum. The valve also has a PTFE seal to prevent incoming pressure loss to exhaust at the pump casting, which can occur under hot abuse conditions.
Fits pump stators manufactured up to February 2004. Does not fit No. 29541135 or later pump stators.
Contact a Sonnax Parts Distributor.