Performance Upgrades for the A727 Transmission in Your HEMI-Equipped Charger

Posted by on Tuesday, August 5th, 2014

The A727 is a heavy-duty, three-speed automatic transmission designed and built by the Chrysler Corporation for use in Dodge, Plymouth, and Chrysler vehicles. This aluminum cased transmission was first put into use way back in 1962 (there was an earlier cast iron version produced before this date; the A488) and was used all the way up to the end of the 1991 model year. That’s a very long run for any automatic transmission!

The A727 was a pure mechanical and hydraulic-controlled transmission and incorporated no electronics except for a neutral safety switch. The A727 automatic transmission used a 2.45:1 first gear ratio and a 1:1 final gear ratio. Eventually, the A727 was replaced by the transmissions that used an overdrive gear, including the A518 and the A618. Internally, the A727 goes by the code of 36Rh and 37 RH.

This transmission could be found in many Chrysler products, including the Dodge Challenger, the Ram pickup truck, the Dodge Dart, the Coronet, the Demon, and the Dayton. It was also found in the ultra-high performance Dodge HEMI Charger.

Dodge Charger (Wiki)

The 426 Hemi Dodge Charger came with the A727 automatic transmission.

The 1970’s Dodge Charger was a two-door sedan made popular in the TV series The Dukes Of Hazard. Many hundreds of these cars were destroyed while the series was being filmed in southern California, making them that much harder to find today. The Charger was a big and heavy car. The second generation Charger was a big departure in design from the original mid-1960s Chargers, and its swooped-back body was an instant success.

The Charger could be ordered with a number of different engines, from the 318 small block to the large 440 big block. But it was the legendary 426 HEMI engine that got the most attention. The factory listed this engine at a very conservative 425 horse power, but it is widely acknowledged that it made over 500 horse power. Most HEMI-equipped cars were backed by the A727 transmission, although some were equipped with a four-speed manual transmission.

It’s easy to make more horse power with a 426 HEMI engine, but not many people give much thought to the fact that the A727 should be beefed up to handle the additional power. Here are a few good performance accessories for your A727 automatic transmission:

Modify the vlavle bodyThis single accessory is the biggest bang for your performance buck. Shift kits usually come with three different modes that you can choose from during the installation: towing, street, and strip. Although tempting, I highly recommend that you do not install the strip mode for street use. The shifts in the strip mode have extremely hard shifting characteristics and will eventually break something on your Dodge Charger.

Install  performance aftermarket cooling device. Excessive heat is the number one cause of A727 transmission failures. The best way to control the transmission from overheating is to install a large transmission cooler. Be sure to mount it in a location that will see good airflow when the vehicle is in motion.

Sooner or later, due to high mileage or abuse, you’ll be faced with the decision to replace the A727 transmission in your Dodge Charger. We highly recommend doing so with a re-manufactured transmission over one that was simply rebuilt. A re-manufactured transmission will include major internal modifications and upgrades designed to make it both stronger and more durable. To learn more, ETE Reman is just a quick phone call or email away!

Leave a Reply

You must be logged in to post a comment.