How to Tell the Size of My Ford Rear End

by Gail Delaney
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If you have a Ford, you can identify the size of the rear end in a matter of minutes. You do not have to take the rear end apart or drive your Ford into the shop to have the mechanics tell you the size. Ford has made it relatively easy to determine the size, and you won’t get too dirty, either.

Step 1

Look up the specs in the manual that came with your car. You can also look in the Chilton Repair Manual for the information.

Step 2

Crawl under the vehicle and find the tag, located on one of the nuts that holds the third member. The tag shows the size of the rear end, serial number and gears.

Step 3

Put a socket wrench on the lower bolts of the rear end and examine to see if the socket fits. If the socket fits on straight and does not hit the case, you have an 8-inch rear end. If the socket does not fit this position, then you have a 9-inch rear end.

Step 4

Measure the diameter of the ring gear. This measurement equals the size of your rear end.

Step 5

Count how many bolts are on the inspection cover. If you have 10 bolts, then your Ford has a 7.5-inch or an 8.8-inch rear end. If you have 12 bolts, then the rear end is a 9 inches.

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