S&S, Twin Cam breather valve

Description

Reed style breather to fit S&S oil pump as used in all S&S T-Series (Twin Cam style) engines and OEM pump in 03-10 OEM engines. Will tackle problems with OEM engines as Oil Carry Over (blowing oil out of the breather system), a common problem for years. Usually at sustained high speeds and worse with big inch engines. This problem can still be present in OEM Twin Cam engines. S&S designed this aluminum crankcase breather valve containing four steel reed valves, which effectively prevents wild turbulence in the cam chest and rocker boxes. Air and oil mist can escape from the crankcase, but is not allowed to re-enter. Any oil blowing out of the crankcase breather is stopped. A slight increase in horsepower (one to two HP) and torque can be expected. The breather valve is installed over the pinion shaft, inside the pinion bearing bore, and retained between the bearing outer retaining ring and the oil pump.



Note: Will not fit TCB (Softail) models.

Replacement parts:

970628 Seal.

970629 O-ring (for 99-02 FLT, Dyna).

970630 O-ring (for 03-06 FLT; 03-05 Dyna).

970631 Reed valve.

970632 Reed valve stop.

970634 Reed valve screws.

970610 Wave spring (for 99-06 FLT; 99-05 Dyna with S&S pump).

970635 Wave spring (for OEM & S&S cases with stock oil pump).

970636 Wave spring (for S&S .375" wider SA cases with stock oil pump).

970637 Wave spring adapter (for S&S .375" wider 'Special Application' cases with S&S oil pump).

Specifications

Fitment

03-10 Dyna, FLT/Touring with OEM cases; 99-17 style S&S T-series (Twin Cam style) cases (NU)

Part numbers