Ford automatic transmission A4LD repair manuals - is a part of Ford repair manuals: Manual and Atomatic Transmissions. This part contains the detailed description of works and all necessary transmission diagrams for Ford Aerostar, Ranger and Explorer automatic transmission A4LD. Contents:
- description and operation;
- diagnosis and testing;
- cleaning and inspection;
- removal and installation;
- disassembly and assembly;
- specifications;
- special service tools.
Ford automatic transmission A4LD description:
Ford automatic transmission A4LD is a four-speed automatic overdrive transmission with a lockup torque converter. The 3-4/4-3 shift functions and converter clutch lock/unlock are controlled by the EEC-IV processor through a 3-4 shift solenoid and a converter clutch solenoid. The EEC-IV electronically controls the converter clutch solenoid, which hydraulically operates the piston-plate clutch in the torque converter that provides lockup (solid drive) and unlock functions.
The electronics also prevent clutch application in engine modes where noise, vibration or harshness concerns would be most evident in a solid-drive transmission. These modes are: tip-in/tip-out; application of brakes; closed throttle; cold engine; very heavy/wide open throttle; low engine speed to minimize lugging boom; 23.5 inches of mercury absolute barometric pressure or below in the intake manifold. Ford automatic transmission A4LD also provides wide open throttle forced downshifts. When driving in excess of approximately 64 km/h (40 mph) and with the accelerator fully depressed to the floor, the transmission will downshift to second gear for maximum acceleration. If the accelerator is depressed fully to the floor at speeds below 48-56 km/h (30-35 mph) the transmission will downshift to first gear.
Ford automatic transmission A4LD operation:
Ford automatic transmission A4LD operations, provided by seven operator-selected positions of the selector lever, are as follows:
| P, R and N | Same as other Ford automatic transmissions. |
| (D) (overdrive) | Normal driving position. Selection of this position provides all automatic shifts including the application and release of the converter clutch. The transmission may also be shifted manually between all forward ranges. |
| D (drive) | Selection of this position provides all automatic shifts, including the application and release of the converter clutch, except the shift into overdrive. This position can be used when overdrive is not wanted such as hilly or mountainous terrain or when towing a trailer. |
| 2 (manual second) | Selection of this position provides only second gear operation regardless of vehicle speed. It is useful for start-up on slippery surfaces or to provide engine braking on downgrades. |
| 1 (manual low) | Selection of this position at start-up or when selected at lower speeds provides only low (first) gear operation. Selection of this position at higher speeds results in a downshift to second gear. An automatic downshift to low will occur when vehicle speed decreases to approximately 48 km/h (30 mph), depending on axle ratio and tire size. Once in low, the transmission will stay in low until the selector lever is moved to another position. |
When operating in the overdrive (D) position, the transmission will automatically shift gears from first to second and from second to third and third to fourth gear overdrive. The shift into overdrive decreases engine rpm by 25 percent and occurs when the vehicle approaches the desired cruising speed and the driver eases up on the accelerator pedal. The converter clutch is applied after the shift into overdrive. The converter clutch and overdrive applications are based on both engine speed and vehicle speed by combined transmission hydraulics and on-board computer electronic controls (EEC-IV). The converter clutch can be applied in third gear in the D position, and in fourth in the (D) position. Because of this feature, the transmission may be sensed as executing as many "shifts" (in the overdrive (D) position) as would a five-speed transmission.
Two functions have been incorporated in Ford automatic transmission A4LD for times when the driver requires acceleration or more power for negotiating grades or driving into very strong headwinds. They are:
- disengagement of the converter clutch to achieve added acceleration from the resultant increase in engine speed;
- a part throttle 4-3 (overdrive to direct drive) downshift for further acceleration.
These events can also occur during cruise control operation when more power is required to maintain the selected speed. While driving at highway speeds, four different engine speeds can be obtained by transmission operation in:
- overdrive with the converter clutch engaged (lowest engine speed for best fuel economy);
- overdrive with the converter clutch disengaged (slightly higher engine speed for improved acceleration);
- third gear (direct drive);
- full throttle in second gear for maximum acceleration.
Ford automatic transmission A4LD gaskets and seals:
All automatic transmissions are equipped with high temperature resistant seals. This includes those seals used on the manual and kickdown levers, the O-rings and oil pan gasket. Under no conditions should older design seals be used on the transmissions.
Ford automatic transmission A4LD service identification:
All vehicles are equipped with a Safety Standard Certification Label affixed to the left (driver's) side door lock post. Refer to the stamped code in the space marked "Trans" for proper transmission identification. Refer to «Section 00-01», Identification Codes, for the specific transmission identification coding. The transmission is also identified by a tag on the transmission body.
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