Expert Tips to Extend the Life of the 4F27E Transmission

Posted by on Thursday, February 21st, 2013

The 4F27E is an automatic trans-axle used by both Ford and Mazda. This transmission replaced the Ford CD4E. Mazda actually refers to the transmission as the FN4A-EL. The transmission has four forward gears, one of which is an overdrive gear. The 4F27E transmission was first put into production in 2000 and is still made today. Although a decent transmission, it still has its fair share of problems.

4f27E transmission diagram


The 4F27E has a number of electrical solenoids. The solenoids are subject to failure which can result in a host of transmission problems. To access the solenoids, all one needs to do is drop the transmission pan. All solenoids are mounted to the bottom of the valve body. They can be checked quickly using an ohm meter to determine the resistance in the wire coils housed inside the solenoids. Please refer to the owner’s manual for the correct readings. If the reading is too low, then you likely have a short in the coil pack. If you get no reading, then you most likely have a broken wire in the coil.

Another common area of failure involves the accumulator. Often the accumulator bore will get damaged and the piston will stick. The accumulator is designed to take some of the fluid while a component is being applied, prevent that band or clutch from applying too quickly.  If the accumulator sticks in the wrong position you could end up with some very harsh shifts.

4F27E transmission cut-away


Here are a few things you can do to help extend the life of your 4F27E:

1)  Install an aftermarket transmission cooler.  Excessive heat is the number one killer of automatic transmissions. Be sure to mount it somewhere where it will get good air flow.  If finding a place to mount it with good airflow becomes a problem, consider buying a cooler with a built in fan. This will allow you to mount the cooler almost anywhere, including to the body. While you’re at it, you might as well install a transmission temperature gauge so you can keep an eye on the temperature.

2)  Use a synthetic fluid. Just be sure to use one that has the same properties as the recommended organic fluid. Synthetic fluids tend to be much more resilient to breaking down from excessive heat. In theory, you can also go longer  between oil changes. Don’t forget to change the filter with a high quality unit at the same time you replace the fluid.

3)  Get yourself a shift kit. By modifying the timing of the shifts and the way the clutches and bands apply, you can prevent excessive wear and heat buildup.

4F27E transmission shift kit


If you get to the point where it makes more sense to replace the transmission than fix it, consider going with a re-manufactured transmission instead of one that was simply rebuilt. There are a lot of older compact Fords and Mazdas out there being driven by families struggling to get by, or college students paying off loans.

Transmission maintenance can prevent problems, but if one of these transmissions fails, you can help out your customers by cutting costs. While just as good as a new transmission, a re-manufactured transmission costs a whole lot less. They also usually include upgrades that will make the transmission more durable. A re-manufactured transmission also comes with a much better warranty: three years compared to 90 days for a rebuilt transmission.

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