Rear axles & Differentials
Illustrations, identification numbers, parts lists, and other information on Ford's rear axles and differentials.
But it can be complex to sort your way through all the information, so there are examples to help.
But it can be complex to sort your way through all the information, so there are examples to help.
If you are just wondering what rear axle you have, the best way to find out is to decode your certification label. But if you are looking for parts for your axle, follow along on these examples:
The Applications Listing tab lets you look up what axle you have by the shape or the application. The ID # To Part #, Axle Ratio, etc tab lets you cross the ID # from the tag on the axle to the axle's part number, axle ratio, parts list, etc.
Rear axle illustrations, part #'s, capacities, and tag decoding for the axles used on the 1980 - 86 Ford trucks.
|
|
This is a section from the 1981 factory shop manual.
This is a section from the 1981 factory shop manual.
This is from the 1986 factory shop manual:
Our member Johnathan/StraightSix has installed an Eaton Truetrac in his 8.8" rear axle, even though Eaton doesn't produce the Truetrac for the 83-86 3/4" cross pin version of the axle, only the '87+ version of the axle with a 7/8" cross pin. His how-to is below:
Section 15-41 from the 1985 factory shop manual.
The following chart let's you figure out the specifications of axle shafts used in Ford rear axles. But you'll need the part number of the axle shaft, which you can get from the Parts List tab.
|
Finding Parts: For an example, let's look for the differential side gear for Big Blue, which is an '85 F250HD w/a 10.25" locking axle. On the certification label I see it has a "39", and when I decode that on the axle ratios page, shown to the right, it says it is a Ford axle with a 6.25M rating and 3.55 gears. |
|
|
Now we need to go to the Rear Axle Application Chart, shown to the right, which is on the Identification tab and then the Applications Listing tab, below. On there I see that there are two Ford axles for 1985 with that rating - a locking and a non-locking. Big Blue has a locking axle, so it is shown on Illustration PG 11 and parts list # 260.
|
|
|
But I don't know exactly what Ford called what I call the differential side gear, and their terminology can be a bit unusual, so I need the central part of the part number. (A part number has a prefix, like E5TZ, a central part, like 4236, and a suffix, like B.) And to find the central part I'm going to look at Page 11 of the Illustrations tab - shown to the right. And there I see the side gear and it is # 4236, which is the central part of the complete part number.
|
|
|
With that info I open the Parts Lists tab and realize that there are 48 pages of information. So I go to the top right of the first page and click the "Pop-out" icon which opens it in a new tab on my browser. Then I click Control & F at the same time and get a search function. I type "Parts List No. 260" into the search bar and voila, I'm on Page 56 with the start of Parts List No. 260 highlighted. |
|
|
Now that I'm in the right parts list I scroll down to the next page to find "4236" and there it is: E5TZ 4236-B Gear (differential side) - the number I've been looking for. |
|
GEAR RATIO: Lets say that you want to determine the gear ratio of the axle you've found but all you have is the ID # on the tag on the axle, no certification label or even what the axle came out of.
To do that we'll go to the Identification tab followed by the ID # To Part #, Axle Ratio, etc tab and look that ID # up:
To do that we'll go to the Identification tab followed by the ID # To Part #, Axle Ratio, etc tab and look that ID # up:
Axle Shaft Spec's: Or, let's say we want to find the spline count or length of the axle shaft in an axle we've found. Let's again use E0TA-CEA as our example, and in the snippet from the Rear Axle and Differential Carrier Chart, above, we see that it uses Parts List No. 185. So we go to the Parts List and find. Having looked at the Illustrations tab I see that the axle shaft is generic PN 4234, so the whole part number is D5UZ 4234-G: