Disassembly & Reassembly
- Remove oil strainer. Remove bolts retaining upper body, lower body and separator plate together. Remove upper body. Remove separator plate. Note location of check valves, springs and relief balls (valves). See Figure -34.
- Remove side plates and parts. See Fig 1 , Fig 2 or Fig 3 . To reassemble, reverse disassembly procedure. Ensure springs are installed in proper position. Tighten the upper-to-lower valve body retaining bolts to specifications in sequence. See Fig 4 . Refer to the VALVE BODY SPRING SPECIFICATIONS table.
VALVE BODY SPRING SPECIFICATIONS
| Application | Free Length In. (mm) | ||
|---|---|---|---|
| Downshift Valve (N4A-HL) | .866 (22.00) | ||
| Orifice Check Valve | .610 (15.49) | ||
| Pressure Modifier Valve | |||
| Miata & MPV | .610 (15.50) | ||
| RX7 & 929 | .780 (19.80) | ||
| Pressure Regulator Valve | 1.693 (43.00) | ||
| Second Lock Valve (N4A-HL) | 1.319 (33.50) | ||
| Throttle Back-Up Valve | |||
| Miata | 1.417 (36.00) | ||
| MPV With G6 Engine | 1.173 (29.80) | ||
| RX7 | .780 (19.80) | ||
| 929 | |||
| DOHC | .599 (15.22) | ||
| SOHC | .720 (18.30) | ||
| Throttle Relief Check Valve | |||
| RX7 & 929 SOHC | .984 (25.00) | ||
| All Others | 1.055 (26.80) | ||
| N-D Accumulator Valve | |||
| RX7 | 1.709 (43.40) | ||
| 929 | |||
| DOHC | 1.709 (43.40) | ||
| SOHC | 2.512 (63.80) | ||
| N-R Reducing Valve (RX7 & 929) | .571 (14.50) | ||
| Back-Up Control Valve (RX7 & 929) | .839 (21.30) | ||
| N-R/2-3 Accumulator Valve | |||
| RX7 | 2.984 (75.80) | ||
| 929 | |||
| DOHC | 3.500 (89.00) | ||
| SOHC | 3.248 (82.50) | ||
| 1-2 Accumulator Valve | |||
| RX7 | 2.465 (62.60) | ||
| 929 | |||
| DOHC | 2.465 (62.60) | ||
| SOHC | 2.440 (60.00) | ||
| 1-2 Reducing Valve | |||
| RX7 | .768 (19.50) | ||
| 929 | |||
| DOHC | .768 (19.50) | ||
| SOHC | .787 (20.00) | ||
| 1-2 Shift Valve | |||
| Miata | 1.059 (26.90) | ||
| MPV | 1.102 (28.00) | ||
| RX7 & 929 | 1.039 (26.40) | ||
| 2-3 Shift Valve | |||
| Miata | 1.614 (41.00) | ||
| MPV With G6 Engine | 1.654 (42.00) | ||
| RX7 & 929 | 1.969 (50.00) | ||
| 3-2 Timing Valve | |||
| Miata | .913 (23.20) | ||
| MPV | .815 (20.70) | ||
| RX7 & 929 | 1.555 (39.50) | ||
| 3-4 Shift Valve | |||
| Miata & MPV With G6 Engine | 1.193 (30.30) | ||
| RX7 & 929 | 1.583 (40.20) | ||