In This Guide
- Vehicle Compatibility – Makes & Models
- A4LD Transmission Overview
- Common Problems with the A4LD Transmission
- What’s Included
Vehicle Compatibility – Makes & Models
- 1985–1990 Ford Bronco II
- 1987–1993 Ford Mustang (when equipped with the 2.3 I4)
- 1987–1988 Ford Thunderbird (when equipped with the 2.3 I4)
- 1985–1994 Ford Ranger
- 1986–1994 Ford Aerostar
- 1991–1994 Ford Explorer
- 1991–1994 Mazda Navajo
A4LD Transmission Overview
The A4LD pioneered electronic controls for torque converter lockup. Specifically, the 3-4 shift was controlled by an electrical solenoid. Meanwhile, the other gears maintained a hydraulic control system. The 3-4 gear shift is the most common one used while driving at traffic and highway speeds.
Because of its status as a pioneer in electronic transmission control, it could be expected to have problems. Specifically, the two solenoids that controlled the torque converter lockup and the other one attached to the 3-4 shifter tended to fail often.
The solenoids failed due to Ford’s inexperience in creating electronic components for the transmission. Heat overworked the metal wire that was used to create the magnetic assembly.
After the wire broke down from excess heat, there was no way to power the electromagnet and use the controls. It could also create a short circuit, which had the same effect. Either the torque converter would no longer lock up, or the vehicle would no longer be able to shift into fourth gear.
Common Problems with the A4LD Transmission
The A4LD has a long history of problems and failures in its years of service. Drivers who still own a vehicle with this transmission should watch out for the following problems:
First, a lack of overdrive. Often, this happens because the overdrive sprag locks up and doesn’t provide any give to the forward clutch spring pack. Shifting into overdrive rips the spring pack completely free, and the only way to fix it is to completely disassemble the transmission and replace the broken part.
Second, the transmission might keep slipping. This happens most often in the A4LD when the kick down cable loses its adjustment. In turn, this makes the transmission slip and destroy clutches. The transmission has to be fully disassembled before any repairs can be made.
Third, you might lack third gear or lack the ability to do a proper 1-2 shift. When this happens, the modulator is defective. If you are doing repairs at any point and notice fluid coming out of the modulator vacuum line, it’s an indicator that the modular has failed or is about to fail. Luckily, it’s an easy and cheap fix.
Finally, there could be fluid leakage at the front. Over time, the front seal can harden or simply wear out. When this happens, it doesn’t hold its shape and cannot stop fluid from leaking out. Transmission fluid provides cooling and lubrication. It could also be the front pump bushing. This isn’t a quick fix; to get to either the front seal or the front pump bushing, the transmission has to come off the vehicle.
If you still have an A4LD transmission and don’t yet want to replace it, you can extend its working lifespan using a few simple methods and modifications.
Place an aftermarket transmission cooler in the return line in addition to the factory cooler. It can help keep the transmission cool because too much heat buildup will destroy it. You should keep the temperature of the transmission below 200 degrees Fahrenheit maximum.
Prevent debris from getting into the cooler by installing an extra inline fluid filter on the line going toward the radiator. By keeping debris out, you increase the life of the cooler because it has to do less work and fluid can flow more freely.
Add a Sonnax valve body kit. This kit includes both a sleeve and a valve, both of which add pressure inside the valve assembly. When pressure increases, it keeps the clutch packs from separating, as well as keeping the clutches and associated bands from overheating.
Change your transmission pan from a steel one to an aluminum one. Also, make it deeper, provided your vehicle has enough ground clearance. The reason for the extra size is to hold more fluid. Also, steel does not dissipate heat as well as does aluminum. Therefore, you run less risk of overheating.
Use an aftermarket shift kit. By making this adjustment, you can increase the transmission line pressure, decreasing the time it takes for the clutches and bands to do their work.
Keep an eye on transmission fluid levels and status. Dark fluid or leaking fluid indicates a problem. You should probably change the fluid every 20,000 miles. If you have any doubts, take your vehicle to a mechanic and have him run a check.