The DJ-5A was introduced in 1967, beginning the lettering system indicating changes within the series. The DJ-5A (Kaiser Co.) used a standard CJ front end, with a four-cylinder Chevrolet Nova engine and two-speed Powerglide automatic transmission, with a T-handle shifter located on the floor next to the driver's seat. The main body was a single unit, resembling the earlier Jeep when equipped with the metal Extreme Cold Weather Enclosure hard top. The models used by the United States Post Office had right-hand drive (without power steering), and were built in a lighter, less durable design than the standard Jeep. These changes included the use of C-channel frame rails (as opposed to the box rails of the CJ-5) and, while the hood was the same dimensions as (and interchangeable with) the CJ, it did not have the reinforced design of the original. Also, the standard configuration had only a driver's seat and a letter tray installed. This decreased curb weight, combined with different leaf springs than other models, allowed carrying more cargo weight behind the driver. The metal side doors were also designed to slide open and closed, and could be locked open while driving. They were supported by ball bearings, which ran in a channel just under the rain gutter, and a plastic retainer ran in a small channel along the body. A worn, damaged or lost retainer would allow the door to swing outward, fail to engage the rubber stop on the rear bumper, and slide all of the way off of the channel (and the vehicle). A single, hinged rear door gave access from floor to the bottom of the hard top, and was the width of the open area between the wheel wells. There were no cutouts in the body for the rear wheels, which made tire changes more difficult, as even when the frame was jacked well off the ground, the axle did not fall enough for the tire to clear the body. The DJ-5A used standard 15-inch passenger car tires, with no provision for carrying a spare. While the front bumper was of the standard CJ design (though thinner and lighter than the original), the rear bumper was a unique design, a single stamped part which ran the full width of the vehicle. At each end was a rubber stopper for the sliding doors. The 10-gallon fuel tank was under the rear body, just ahead of the bumper. In 1971, a unique five-slot grille without turn signals that was used only on postal Jeeps was introduced.