Debris and constant oscillation of the outer reverse modulator valve in listed Ford units can create casting bore wear and scratches on the critical valve spools. This allows valuable reverse and/or EPC pressure to leak, resulting in delayed Reverse engagement, no Reverse, and a burned reverse band or direct clutch.
Sonnax outer reverse modulator valve 37947-52 is a direct replacement for unworn bores containing valves with noticeable spool scratches. For worn bores containing valves with significant scratches, this direct replacement 37947-52 valve should be used in conjunction with the sleeve in Sonnax kit 37947-11K (reaming required).
If bore is unworn, use Sonnax valve to replace damaged or scratched OE valve. If excessive bore wear is detected, use Sonnax valve in conjunction with Sonnax sleeve in 37947-11K. Worn/damaged OE valves used in a sleeve will not optimally restore hydraulic function.
Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if a visual inspection of critical valve spools finds excessive scratches.