The A4LD 4-speed, overdrive transmission has been used in the Ranger/Bronco II/Explorer platform since 1986. As most of the early overdrive auto transmissions, the A4LD was not real reliable in the early years. The first major change came with the introduction of the 4.0 in 1990. While still an A4LD, the 4.0 version was significantly stronger than the non 4.0 versions. It also had a computer controlled torque converter lock-up. In 93.5 another major upgrade of this transmission occurred. In addition to the computer controlled lock-up, the transmission also got a computer controlled overdrive engagement. Internally, most of the thrust washers were replaced with torrington bearings, which made the transmission much stronger.

While the A4LD has gotten a bad rap, it is actually a good strong transmission. The newest version is still an A4LD, it just goes by another name(4R55E) due to the fact that it is completely computer controlled, and has a 5th gear.

There are modifications and upgrades available to this transmission. Better grade clutches and bands, better converters with improved lock-up clutches and brazed fins (stock converters were known for clutch failures, which takes out the entire trans), welded planetary cages, shift kits, and the ability to upgrade a non 4.0 transmission to 4.0 specs makes this transmission very versatile. At its strongest (off-road race application), these transmissions are holding up to V6's making in excess of 300hp. Once the engines get much higher than that (depends on usage) the main shafts will start bending.

One of the most interesting upgrades available for this transmission is the off-road race package. This includes numerous valve body and internal modifications. These modifications can be made by Doug Hamby of Dougs Transmissions only, due to the fact that they were developed between him and FMC. What this modification does for you, is give you an automatic with all of the advantages of a manual....... and none of the downfalls. Run in drive, you can split the 3 gears with overdrive, and you can lock-up the converter in any of the gears. This gives a much greater availability of ratios, and makes it real easy to keep the engine in its power curve. Also, because you can lock-up the converter whenever you wish, it also helps to keep the transmission cool. This mod also allows the transmission to be used completely manually.

When having an A4LD rebuilt, there are a couple of things that you need to make sure of. First and foremost, do not let a shop do a soft parts fix only (clutches, servos, and bands). This will almost ensure that you will have another repair needed right after the 1-year warranty is out. Other things you want to have replaced are: forward one-way clutch (always), overdrive drum (stamped tin, replace if out of round or heat damaged), pump (Ford only, rebuilds are prone to failure), and the converter (get the better converter with the improved lock-up clutch and brazed fins). Also, get references from the shop and call the people. Just because they can rebuild TH350's and C4's does not mean they know what they are doing with overdrive transmissions.

One of the best things you can do for your auto transmission is get the largest, aftermarket, stacked plate cooler you can fit behind your grille. The factory cooler is marginal at best, due to its being tied in with your radiator. Remember, with that set-up, if you overheat your engine, you will overheat your transmission. Heat is the biggest enemy of the automatic transmission. Change your fluid and filter every year, or every 12-15,000 miles if used hard. Use ONLY the fluid recommended by Ford. Only use synthetic fluid if it is required by Ford. With proper maintenance, these transmissions should last well over 100,000 miles. - Gloria Roozen