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All Datsun 1200s were fitted with a 56 or 56A-Series_Transmission. Most Datsun 1200s come with a 4-speed floor shift manual transmission (FS4W56). Some Standard models had a 3-speed column shift (R3W56). In Japan, the special GX-5 model came with a direct-fifth (non-overdrive) 5-speed (F5W56). [Note, it is possible that the 56A trans was first developed as the five speed & if so, then it's possible/probable that no 56L five speeds were made. The four speed 56A trans was first offered in April of 1973]
Main article: 56-Series Transmission
In the United States, Canada & Australia, all manual shift 1200s had the 4-speed transmission. The two competition four speeds [Option 1 & 2 four speeds in 56 series only] & the five speed was also sold by Datsun Competition in close-ratio and wide-ratio versions. In the five speed version, only the close ratio Option 1 gearbox was offered by Datsunsport Australia, not the standard five speed when I enquired in 1981.
Note that the 4-speed transmission was redesigned in April 1973. Gearsets are not interchangable between early and late transmissions.
The standard 4-speed was well suited to the A12 Engine's torque curve. With a steep 3.757 first gear and a medium-steep 3.90 rear Differential pushing small-diameter 12" Tires, it gave the little 1200 engine enough torque multiplication to take off easily, even with no throttle input. Yet top (4th) gear was good for 90mph. The 5-speed improved upon this by adding an extra gear between 1st and Top.
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Powerflow Diagram
The countershaft always rotates with the input shaft. The output shaft (mainshaft) does not move when in neutral -- the main gears just spin freely. When the shifter is moved, it pushes one of the synchro collars against a gear, locking it to the mainshaft. Reverse is a special case, it pushes an idler gear between the counter and main gears, reversing rotation of the mainshaft.
Maintainence Specifications
3-speed, 4-speed
- Synchromesh type: Warner type. Synchromesh on all forward gears in both 3 & 4 speed models.
- Oil capacity: 1.2 liter (2.5 US pint, 2.125 Imperial pint)
- Oil type:
- Oil Drain plug & Filler plug torque: 4.0 - 6.0 kg-m (29-43 ft-lb)
- Speedometer gear ratio:
- 17/5
- 18/5 for Wagon
Ratios
- 3-speed R3W56L steering column shift
- 1st - 3.380
- 2nd - 1.734
- 3rd - 1.000
- Rev - 3.640
- 4-speed F4W56L floor shift
- 1st - 3.757
- 2nd - 2.169
- 3rd - 1.404
- 4th - 1.000
- Rev - 3.640
- 4-speed Option 1. floor shift [competition close ratio gearbox]
- 1st - 2.862
- 2nd - 1.908
- 3rd - 1.350
- 4th - 1.000
- Rev - Not listed
- Source. Datsun B110 Competition Tune Up Manual 1974
- 4-speed Option 2. floor shift [competition ultra close ratio gearbox]
- 1st - 2.169 [Note that first gear is the same ratio as the standard models second gear]
- 2nd - 1.593
- 3rd - 1.233
- 4th - 1.000
- Rev - Not listed
- Source. Datsun B110 Competition Tune Up Manual 1974
- 5-speed F5W56A floor shift
- 1st - 3.757
- 2nd - 2.374
- 3rd - 1.659
- 4th - 1.291
- 5th - 1.000
- Rev - 4.040
- 5-speed F5C56A floor shift [Option 1 competition gearbox. Supersedes Option 1 & 2 four speed gearboxes]
- 1st - 2.676
- 2nd - 1.691
- 3rd - 1.398
- 4th - 1.182
- 5th - 1.000
- Rev - Not listed
- Source. Datsun B110 Competition Tune Up Manual 1974
Bellhousing Pattern
All A-series engines use the same bellhousing pattern. This means any rwd transmission, from B10 to B310, fits any A-series engine.
No other Nissan engine shares this pattern. This means transmissions from Datsun 1600 or any other will not fit an A-series engine.
Weight Comparison
- 17.8kg (39.2 lbs): 56-series 4-speed (B110 edition)
- 24.8kg (54.6 lbs): 60A 5-speed (KPB310 edition)
- 31 kg: 63a gearbox complete with clutch set up (with no gearbox mount)
- 36.5kg: T50 with bellhousing and clutch set up
- 43.5kg (54.6 lbs): CA18DET 5-speed (rwd edition)