Читать книгу Ford Differentials - Joseph Palazzolo - Страница 13

People have been climbing around scrap yards for years to find the best examples of the 9-inch axle. If you are fortunate enough to find an axle with the identification tag still attached, it will help solve part of the mystery of what application the axle came from and what might still be inside.

The axle identification tag is located at about the 3 o’clock position under the third-member mounting nut when you are looking straight at the front of the axle. These tags are typically quite beat up, twisted, and rusted over the years. These tags were not that informative on the early units, so from 1957 to 1962 the tag just referenced axle ratio. In 1963, Ford included more information.

This is a typical axle tag that has been removed from the third member. The code, 4L11, tells us that it is a 4.11:1 ratio with a limited-slip or Traction-Lok differential. It also has a 9-inch ring gear.

The axle tag typically has two lines of numbers and letters stamped on it. The format has changed over the years but mostly follow this sequence:. The top line typically starts with a three-digit axle model code (or the prefix of the part number), followed by a dash, and then the suffix. The axle model codes are interchangeable, typically the suffixes are different for a revision change but the axle is still interchangeable with one having the previous suffix. There may be a second dash and more numbers and letters on the top row if there are specifics that are unique for interchange information. Typically with just this information, you can cross reference what you need to know about the axle. The last set of digits on the top row on the right side is the date code.

The bottom line begins with the ratio being the first set of numbers. If an L is included, it was equipped with a limited-slip differential or Traction-Lok. The middle number is the ring gear diameter in inches, typically an 8 or 9. The last set of numbers is the vehicle plant code.

If the axle tag is missing, as most are, you need to remove the third member in order to know what ratio you have and if it has a limited-slip or not.

This custom axle tag was obviously hand cut as evidenced by the sharp tin-snipped-looking ends and includes DSO, for Dealer Special Order. Notice that the date code is C9UA with the ring gear size of 8.7. This was an 8.75-inch ring gear in a 9-inch housing. These were used sporadically until about 1969. You can install a true 9-inch gear in these housings as well.

Don’t be surprised if the tag you have does not exactly match this. There are also unique domestic special-option tags, which don’t follow the format.