How to Read a Ford Truck Axle Tagby Cassandra Tribe
Ford truck axles are identified by a small tag attached to the differential casing on the rear axle in most cases. The only axles that are marked differently are ones made by Dana. The same markings are used but they are placed on the casing and the long shaft of the axle rather then the tag. The tag will tell the date the axle was made, the factory, the ratio, pinion gear and model all information that is needed when rebuilding or repairing the axle.
Crawl under the truck so the cover to the differential housing can be seen. The differential housing is the bell style housing located near the center of the rear axle. The cover will be on the side of the housing toward the front of the vehicle that the bolts are on.
Wipe the cover clean. Spray brake cleaner on the housing cover if it is greasy and then wipe it clean. Use a flashlight to locate the axle tag that is mounted on the cover or, to see if the tag information is stamped directly onto the cover, indicating it is a Dana axle.
Write down the five sets of data contained on the tag -- or three sets stamped on the Dana cover, the remaining two sets will be stamped on the long shaft of the axle. Each set will contain numbers, letters or an alphanumeric combination that is a unique identifier for the axle.
Translate the date of the axle by finding the alpha numeric code that begins with a number, followed by a letter, followed by two numbers. The first number is the last digit of the year it was made, the letter indicates the month (A through L for January through December) and the last two digits are the day of the month in a 'DD' format. On a Dana axle, the date will be the number stamped on the long shaft nearest the differential housing.
Locate the part of the tag that consists of a series of three letters, a hyphen and then one or two more letters and a possible single digit after that. This is the code for the axle model, the number at the end -- if present -- will indicate if there is a potential interchange possible with another model. Use this code to reference what parts will work with a rebuild or repair of the axle.
Find the two digit decimal number (for instance 7.5). This is the ring gear diameter in millimeters.
Find the gear ratio code. It will either be a three-digit code with a space between the first digit and the remaining two or, it will be a digit and then a letter 'L' followed by two more digits. The 'L' indicates the gear ration is of a locked traction type.
The remaining alphanumeric code will be of varying length and indicates the plant in which the axle was made or, on the Dana axle -- the code is located on the shaft -- the code represents the "Bill of Material" number for the axle.
- Don't waste time trying to look up the model number. Take the number to a parts shop and have them enter it in their database. There are hundreds of Ford axles and that will be the quickest and surest way to decode the specific model.
Things You'll Need
- Clean rag
- Brake cleaner (if needed)
- Axle tag
Cassandra Tribe has worked in the construction field for over 17 years and has experience in a variety of mechanical, scientific, automotive and mathematical forms. She has been writing and editing for over 10 years. Her areas of interest include culture and society, automotive, computers, business, the Internet, science and structural engineering and implementation.