Overhaul - A4LD: Description

1991 Ford Aerostar Van Cargo Extended, 4.0 X, AWDSECTION Description

The A4LD is a 4-speed automatic overdrive transmission with lock-up type torque converter. Transmission consists of torque converter, planetary gear train, 3 multiple disc clutch packs, 3 bands, 2 one-way clutches and a hydraulic control system.

The on-board EEC-IV system controls operation of a converter clutch solenoid to engage or disengage a piston/plate clutch located in the torque converter. Piston/plate clutch locks and unlocks torque converter to provide "solid drive" function when appropriate.

The EEC-IV system also controls operation of a shift solenoid for 3rd-4th gear upshift and downshifts with 4th gear acting as overdrive. Overdrive (4th gear) is engaged or disengaged as necessary to provide for fuel economy, and torque or acceleration conditions.

Manual selection of gears is also provided. Park, Neutral and Reverse function is the same as all other Ford automatic transmissions. If 1st gear is manually selected at speeds above 30 MPH (48 km/h), transmission will downshift to 2nd gear, followed by downshift to 1st gear when speed decreases to 30 MPH (48 km/h). If 2nd gear is manually selected, transmission will remain in 2nd gear regardless of vehicle speed. This is useful for start-up on slippery surfaces or for engine braking on downgrades.

RENDER: 1.0x

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.