727 / 42RE / 46RE / 47RE / 48RE Governor Bore Plug Kit, Sonnax 22771-14K. Kit provides improved shift timing.
Governor oil leaving the solenoid reacts on the 1-2 and 2-3 bore plugs, which sequentially stroke the shift valves. These bore plugs stroke relative to an opposing spring and variable throttle pressure. Bore wear creates a loss of governor pressure, which affects shift timing. Due to this wear, shift timing changes with operating temperature and often causes a shuttle or late shift. When this leak is combined with a governor solenoid and transducer feedback, they are often too slow to compensate for this oil loss. The throttle circuit is also prone to wear and has TV pressure variation from cross leaks, which then affect shift timing. These cross leaks often come from the 1-2 accumulator piston seals, throttle control valve, TV checkball and or a distorted valve body.
- Kit provides improved shift timing.
- Plugs with PTFE seals improve throttle control.
- Salvages valve body
- 1-2 Shuttle
- 2-3, 3-2 Oversensitive
- Actual governor psi lower than desired
- Difficulty in adjusting shift timing with TV linkage
Wear in the valve body casting at the large diameter of either the 1-2 or 2-3 governor plugs causes governor oil pressure to leak past the shift valve governor plugs.
The Sonnax plugs with PTFE seals prevent critical oil pressure leakage.