Synchronizers let you shift gears without grinding.
Contents |
Overview
Synchro is two cones pressed together until the two shafts run the same speed:
Each gear has a syncho face (external cone) machined with it
The hub is spring loaded so when you move the shifter partway, it presses the baulk ring (internal cone part) against the gear cone.
When they have slowed down to the same speed, the shifter will move all the way in. It happens very quickly, unless the synchros are worn and not working well.
Synchro is basically:
Coupling with hub Baulk rings cone and gear face cone
Coupling with hub. Left: assembled. Right: not assembled
photo
Each synchro set services two gears (arrows). Center arrow points to the Coupling Sleeve
photo
The Coupling Sleeve is what the shifter moves.
The hub is keyed to the mainshaft, so the hub sleeve rotates constantly in the Shift Fork while the car is moving.
The spring lets the hub move side-to-side inside the Coupling Sleeve, but not move too far. On this one there is a total of about 1/4" (5mm) total movement possible. The baulk ring, which fits in the hub, is pushed against the gear cone. Once the two shafts are synchronized, the spring pops the dog teeth together.
56-Series Transmission
F5C56A 5-speed has very different synchros from the 4-speed. It has "C" type synchros (the "C" in F5C56A) which are very different: instead of a brass baulk ring, it has two split rings. Both types have a conical section to them. They are the same type as early Roadster 'servo' type but smaller size.
4-speed: W56 'W' Warner (Borg Warner) BRONZE baulk-ring type syncromesh 5-speed: C56 'C' Type STEEL Porsche split-ring synchromesh.
4-speed: W56 'W' BRONZE baulk-ring type syncromesh
5-speed: C56 'C' Type STEEL synchro
Pitroad will convert your F5C56A to warner synchros for 559,000 yen
See Transmission Gear Part Numbers
4-speed F4W56L, F4W56A 32604-H9000 RING-BAULK (4) > 32604-H1000 <> 32604-H1010 32609-18000 INSERT-SHIFTING (6) 32603-18000 SPRING-SYNCHRONIZER (4) 32601-18000 HUB-SYNCHRONIZER (2) 32606-18000 SLEEVE-COUPLING (2
5-SPEED F5C56A 32601-H7200 HUB-SYNCHRONIZER (2) 32606-H7200 SLEEVE-coupling (2) 32611-H7200 RING-synchro 32612-H7200 BLOCK-thrust 32613-H7200 BLOCK-anchor 32614-H7200 BAND-brake 22 (2) $3 USD 32616-H7200 CIRCLIP
Also see 56-Series_Transmission_Parts#Synchros.
32603-18000 SPRING-SYNCHRONIZER * B11/B12/B13/B14 4-speed, 5-speed, E16, SR20DE, GA16DE * B110/B210 4-speed * B210/B310 4-speed, 5-speed * N10/N12/N13 F4, F5 * T11
4-SPEED EARLY 32601-18000 HUB-SYNCHRONIZER 1 4 SPEED $78 USD 32604-H1000 BAULK RING 32606-18000 SLEEVE-COUPLING $52 USD
4-SPEED LATE 32601-H7301 HUB-SYNCHRONIZER, 1ST & 2ND, 3RD & 4TH $83 USD * same as 60-series Transmission 4-speed & 5-speed (1st & 2nd only) 32604-H9000 BAULK RING $44 USD * also replaces ealier 32604-H1000 * same as 60-series Transmission 4-speed 32606-18000 SLEEVE-COUPLING * same as 60-series Transmission 4-speed & 5-speed
Coupling with hub. Left: assembled. Right: not assembled
album
5-SPEED 32601-H7200 HUB-SYNCHRONIZER, 2nd & 3rd, 4th & 5th 5-speed 32606-H7200 SLEEVE-coupling
- 5-speed was never available in pre-56A form (was designed from the go with improvements over the original 56L 4-speed)
- Used steel "competition" (Porsche type) synchros in F5C56A form
- Datsun Competition in one instance mentioned warner type synchros (F5W56A). However, other Datsun sources such as the B110 and B210 parts catalogs only list F5C56(A) and Porsche type synchros
1984 Nissan Competition Catalog:The 5-speed transmission (FS5C56A) was originally installed on certain non-USA models of the 1200 ... The synchro mechanism is the servo-type (steel). |
60-Series Transmission
Photo: 60L vs 60A
Also see 60-Series Transmission Parts![]()
32604-H9000 RING-BAULK [12-tooth] * F4W56A 4-speed light duty (4) * F4W60L 4-speed heavy duty (4) * FS5W60L 5-speed early (5)
32604-H9700 RING-BAULK * FS5W60A 5-speed late (5)
FS5W60L 5-Speed (1979 B310) 32606-18000 SLEEVE-COUPLING 4th-5th, 2nd-3rd NOTE: 1st gear coupling sleeve is built into Reverse Gear 32604-H9000 RING-BAULK 5 32258-H9001 HUB-SYNCHRONIZER 1ST & REVERSE $133.92 USD 32602-32200 SPRING-SYNCHRONIZER 1ST 3 32608-H9000 INSERT-SHIFTING 3 32234-H9000 RETAINER-SHIFTING INSERT 32601-H9001 HUB-SYNCHRONIZER 2ND & 3RD 32603-18000 SPRING-SYNCHRONIZER 2 32609-18000 INSERT-SHIFTING 3 32601-H9000 HUB-SYNCHRONIZER 4TH & 5TH 32603-18000 SPRING-SYNCHRONIZER 2 32609-18000 INSERT-SHIFTING 3
FS5W60A 5-Speed (1980- B310) 32606-18000 SLEEVE-COUPLING 3 32604-H9700 RING-BAULK 5 32601-H7300 HUB-SYNCRO,1ST & 2ND 32609-H9700 INSERT-SHIFTING 3 32603-18000 SPRING-SYNCRO 2 32601-H7301 HUB-SYNCRO,3RD & 4TH 32609-M0102 INSERT-SHIFTING -0780 3 32609-H9700 INSERT-SHIFTING 0880- <0> 32609-M0102 3 32603-18000 SPRING-SYNCRO 2 32601-H9000 HUB-SYNCRO 5TH & REVERSE 32609-H9700 INSERT-SHIFTING 3 32603-18000 SPRING-SYNCRO 2
32602-32200 SPRING-SYNCHRONIZER * B310 1979 5-speed * 71B 5-speed, 4-speed * 63A 5-speed
32609-M0102 INSERT-SHIFTING * B310 1980 5-speed * N10 1979-1981 F4, F5
32604-H1000
56-series 4-speed * 32604-H1000 Baulk Ring * 32604-H1010 alternate supplier
The original H10 synchros were superseded by the improved #H90 part.
Photo: H10 specs
H10 full-circle toothed
32604-H9000
32604-H9000 replaced H10 * 12 teeth (3 groups of 4, a group every 90 degrees) * 56-series 4-speed * 60L 4-speed & 5-speed
H90 baulk ring
Album: H90
Ouri OR-HY012 replaces * Hyundai AA100-17-266 * Daihatsu 33367-87302-000 * Nissan * 32604-H7300 * 32604-H1000 * 32604-H9000 * 32604-E9801 * 32607-M8011 * 32604-36N21![]()
32604-H9700
32604-H9700 RING-BAULK * FS5W60A 5-speed late (5)
32604-H9700 Synchro BAULK RING & matching gear surface
Album: H97 (60A)
Photo: 32604-H9700 Synchro BAULK RING
Photo: DCIF-2253A (32604-H9700)
63-Series Transmission
A14-equipped B210 5-speed
32604-P0100 RING-BAULK (5) FS5W63A 5-speed 32606-N7100 SLEEVE-COUPLING <> 32606-73200 2 32605-N9000 HUB-SYNCHRONIZER,4TH & 5TH 32601-N9000 HUB-SYNCHRONIZER 2ND & 3RD 32609-73201 INSERT-SHIFTING 6 32603-73200 SPRING-SPREAD 4 32245-N9000 GEAR-REVERSE,MAIN (38T) 32258-N9001 HUB-SYNCHRONIZER,1ST & REVERSE 32608-N9000 INSERT-SHIFTING 3 32602-32200 SPRING-SYNCHRONIZER 3
32604-P0100 RING-BAULK * 63 5-speed * 71B 4-speed, 5-speed
32609-73201 INSERT-SHIFTING * 63 5-speed * Z31 VG30.MT.F5 3rd-4th
32603-73200 SPRING-SPREAD * 63 5-speed * B11/B12/B13/B14 * D21 4WD.KA24E.MT.FT * GC22.Z24I * N12/N13 * S12.VG30E.MT * T11 * Z31.VG30.MT.F5