How to Identify Early Ford Axle
The different types of
early Ford axles are easy to identify by referring to the picture,
which was scanned from an old magazine article that was written by Neal East.
The 1928-1931 Model A axles have a uniform curve from end to end. The spring perch bosses are 2 1/4 inches.
1932 axles were the first Ford axles to be made with a slight drop. These axles are often referred to as '32 heavy axles. They are unique among early Ford axles in having a wider recess at the ends, and a slightly raised area on the front and back of the spring perch bosses in the shape of an I-beam. The spring perch bosses are two inches.
The '33-'36 axles have narrower recesses at the ends and along the center compared to the '32 axles. The spring perch bosses are two inches.
The 1937 V8-60 axles the only early Ford axles that are hollow forgings. They are flat along the front and back, so their cross-section resembles an oval track with short straightaways. They are relatively lightweight and not recommended for heavier cars. Their spring perch bosses are 2 1/4 inches.
1937-1948 axles are not recommended for earlier hot rods. All of the early Ford axles that were made from 1937 through 1948 have shorter distances between the kingpin bosses and the spring perch bosses. When these axles are being dropped, there is less material to work with, so they can't be dropped as far as the '28-'36 axles, and they don't look as good. Also, with the perch bosses being farther apart, this places the wishbones closer to the tires, making the trailing edge of the tires more likely to hit split wishbones on tight turns. Spring perch bosses on all '37-'48 axles are 2 1/4 inches.