Elements of an automatic transmission Ford A 4 LD
1 - oil pan, 2 - oil receiver, 3 - gaskets, 4 - reverse drive, 5 - hydrokinetic control unit, 6 - cover and seals, 7 - forward drive, 8 - medium drive, 9 - vacuum regulator, 10 - acceleration valve, 11 - safety switch, 12 - blocking ratchet and parking lock mechanism, 13 - sealing ring, 14 - rear gearbox housing, 14a - gasket, 15 - latch of the parking lock mechanism, 16 - secondary shaft, 17 - regulator, 18 - Viton O-rings, 19 - governor hub with parking lock gear, 20 - ring, 21 - middle gearbox housing, 22 - oil pan gasket, 23 - rear clutch, 24 - ring, 25 - brake band, 26 - brake drum, 27 - rear planetary gear, 28 - retaining ring, 28a - gasket, 29 - sun gears, 30 - front planetary gear case, 31 - front planetary gear, 32 - needle bearing, 32a and 33 - rings, 34 - front clutch, 35 - o-rings, 36 - direct multiplate clutch, 37 - thrust washer, 37a - o-rings, 38 - medium planetary gear housing, 39 - thrust gasket, 40 - medium planetary gear, 41 - unidirectional clutch, 41a - needle bearing, 42 - multi-plate clutch, 43 - gasket, 44 - thrust gasket, 45 - oil pump, 45a - o-rings, 45b - oil pump shaft o-ring, 46 - oil pump gear, 47 - intermediate plate, 47a - gasket intermediate plate, 48 - hydrokinetic transmission housing, 48a - gasket, 49 - output shaft, 50 - hydrokinetic transmission
From the 1985 model year, a version of cars equipped with the Ford A 4 LD automatic four-speed transmission was introduced. This gearbox is equipped with a hydrokinetic transmission blocking clutch. Its first three gears correspond to those of the Ford C 3 three-speed automatic transmission, while its fourth gear is an overdrive (has a gear ratio that increases the number of revolutions).
Kick-down cable
Initially, the automatic transmissions of the Ford A 4 LD had a mechanical kick-down mechanism (see fig. Adjustment of the kick-down cable in version 1).
Since May 1986 (production date code "GJ") the kick-down mechanism is controlled by a solenoid valve, which provides a more precise gear reduction.
Differences between C3 and A4 LD automatic transmissions
In the four-speed gearbox A 4 LD, after engaging 3rd and 4th gears, the hydrokinetic transmission is blocked, which reduces the heating of the oil in the gearbox, as well as the fuel consumption of the engine. 4th gear has an incremental gear ratio which causes the engine RPM to be 25% less than 3rd (direct) transmission at the same speed.
Pressing the accelerator pedal all the way (kick-down) causes automatic gear shifting to 3rd. This allows you to achieve high accelerations and maximum speed.
Technical data
| Brand and type | Ford A 4 LD |
| hydrokinetic transmission | Trilock with interlocking clutch |
| Hydrokinetic transfer number | 2,8 |
| Oil cooler | tubular |
Control parameters
Control oil pressure (kPa)
Gear lever position | idle pressure | Pressure* at 1600 rpm |
"R" | 450 – 550 | 1850 – 2200 |
"P" and "N" | 350 – 430 | – |
"DE"; "D"; "2" and "1" | 350 – 430 | 1100 – 1300 |
* Engine overload test pressure
The number of engine revolutions during an overload test is 2000–2900 rpm.
Driving speeds at which gear changes occur
| Pedal position | Gear shift | |||
| accelerator | 1 – 2 | 2 – 3 | 3 – 2 | 2 – 1 |
| Accelerator pedal fully depressed | 5800±200 rpm | 5800±200 rpm | 75 km/h | – |
| Accelerator pedal pressed 3/4 | – | – | 50 km/h | – |
| Accelerator pedal not pressed | – | – | 90 km/h (lever in position "2") | between 60 (lever in position "1") |
| The speed numbers given in the table refer to the engine. | ||||
Number of gears
Broadcast | Transfer number | Total number of final drive gear with number | |
3,62* | 3,38** | ||
1 | 2,474 | 8,96 | 8,36 |
2 | 1,474 | 5,34 | 4,98 |
3 | 1,000 | 3,62 | 3,38 |
4 | 0,749 | 2,71 | 2,53 |
Reverse | 2,111 | 7,64 | 7.14 |
* Ford Sierra 1.8 vehicles (carbureted engine) and 2.0i (fuel injected engine.
** In Ford Sierra 2.0 vehicles (carbureted engine).
Lubricant
| Oil quantity | 8.5 dm3 |
| Type | oil for automatic transmissions SQM 2C 9010 A (CJ gear oil) |
Tightening torques
| Hydrokinetic transmission housing to the engine | 30 - 37 Nm |
| Hydrokinetic transmission housing to front automatic transmission housing | 36 - 53 Nm |
| Hydraulic control unit | 9 – 13 Nm |
| Locknut of a bolt of adjustment of a tension of a tape of a brake | 47 - 61 Nm |
| Intermediate holder bolt | 27 – 40 Nm |
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