ISSUE:

Axle assemblies having 10.25 inch ring gears are not being identified as having either a Ford or Dana design limited slip differential.

ACTION:

Identify the differential design for correct repair service procedure and part ordering. Refer to the following Service Tip for details.

SERVICE TIP

If after road or other test it is determined the limited slip differential may require service, check axle build date located on embossed metal identification tag bolted to rear axle cover. Prior to approximately 5/1/96, limited slip differentials used in the manufacture of 10.25 inch ring gear axle assemblies were of Dana design. Beginning approximately 5/1/96, Ford integrated the new Ford design limited slip differential concurrent with the Dana design in the manufacture of 10.25 inch ring gear axles. Identify as follows:

Raise the vehicle on a hoist.

Clean all dirt from the area of the rear axle cover. Refer to the 1996 F-Series Powertrain, Drivetrain Service Manual, Section 05-2A, for rear axle cover removal and installation.

Place a drain pan under the axle and remove the axle housing cover bolts.

Refer to the 1996 F-Series Powertrain, Drivetrain Service Manual, Section 05-02-C, for service details. Refer to the Parts Catalog if other parts are required for the Dana design differential. The Dana design limited slip differential assembly part number is E7TZ-4026-B.

If the differential is of Ford design and new clutch packs are required, order Clutch Pack Kit F75Z-4947-AB. Refer to the Parts Catalog if other parts are required for servicing the Ford design differential. The Ford design limited slip differential assembly part number is F75Z-4026-DA.

The 1997 F-Series Powertrain, Drivetrain Service Manual, Section 05-02B, shows disassembly/assembly procedures for the Ford design limited slip differential. While the procedures shown are correct, the illustrations show the Dana differential case which has radial ribs between the ring gear bolt holes. The Ford case (which should have been shown) flange is flat, and has a cast (raised) “10.25” and “Ford” oval insignia. In addition, the Traction-lok Clutch Gauge Tool (T97T-4946-AH) shown on Pages 05-02B-7 and 05-02B-10 is incorrect. The correct part number is T97T-4946-B. Refer to Figures 1 and 2 for Ford vs. Dana differential case identification and clutch gauge tool with correct part number.