The Ford A4LD Transmission: Don’t Let these Common Problems Catch You Off Guard
Posted by Regis F. on Monday, February 4th, 2013
The A4LD is a 4 speed automatic made by the Ford Corporation. It was based on the original C3 transmission and shares some internal parts with it. The Ford A4LD first went into production in 1985 and was used extensively up through the 1995 model years. The A4LD can be found in many popular Ford vehicles, including the Mustang, Thunderbird, Explorer, Bronco II and many other vehicles. The A4LD was only used behind 4 and 6 cylinder engines.
The A4LD was one of the first transmissions to use electronics to control the torque converter lockup mode. Eventually the 3 – 4 shift was also converted to electrical solenoid control, while the other gears continued to be mechanically / hydraulically controlled.
As a vehicle / shop owner, you should be aware of some of the potential problems that might arise with this transmission. Ford owners have almost come to expect transmission problems, but that doesn’t stop them from being big fans of the Ford Thunderbird, especially the vintage models. Here are a few things to look for the next time you’re dealing with a vehicle equipped with the A4LD transmission.
Since this was one of the first Ford transmissions to use some sort of electronic control, it was plagued with minor electrical problems. The solenoid that controls the torque convert lock up feature, and the other solenoid that controlled the 3-4 shift in some of the later models, were the two parts that failed the most often. With no prior experience or data to work with when it came to the new electronically controlled portions of the transmission, this transmission was sort of a test mule for Ford. The most common thing to fail in the solenoids was the coil of wire that made up the electrical magnet. Over time heat would take its toll on the wire, causing it to melt. This created an internal short in the system and the solenoid would stop working.
When the torque converter solenoid fails you will lose the lock up feature. When the 3-4 shift solenoids fails you will lose 4th gear.
Another common area of failure revolves around the rear thrust washer next to the one way sprag. I would also keep an eye out for problems with the overdrive planetary gear. They were pretty fragile and broke often, and were eventually updated to a six pinion gear planetary.
The governor is yet another common area where problems may arise. Over time, dirt build up can cause the governor to stick, especially when it’s cold. Common symptoms of this problem include a delayed 1 – 2 shift. Try cleaning the governor with Brake Clean to see if that fixes the problem.
Like any other vehicle, lack of properly scheduled maintenance can cause issues. Old fluid can cause the transmission to shift funny or slip. Too much debris in the pan can clog up the filter, which could eventually lead to the total failure of the transmission if the problem is not fixed in a timely manner.
Again, like other transmissions, excess heat can ruin the transmission. These are not heavy duty transmissions, and if you or your customer does something foolish, like tow over the recommended limit or carry too heavy a payload, this can lead to overheating. Check the color of your customer’s transmission fluid to make sure it’s not burnt. If it smells burnt, but doesn’t look burnt, I would still change it.
The Ford A4LD is found in a lot of vintage Ford vehicles. Some of these owners maintain their cars, and keep them looking as flawless as a fresh manicure, polishing the outside until it shines, but it’s your job to take care of the inside. A faulty transmission can leave that car sitting in the garage. Even a wealthy Mustang collector like Jay Leno would appreciate the quality of a re-manufactured unit.