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Ford 8.8 Differential Specifications

by Rob Wagner

Ford developed the 8.8-inch differential primarily for its trucks, sport utility vehicles and vans, but some mid- and full-size Mercury cars also featured the equipment. Numerous versions of the 8.8 with different gear ratios and number of gear teeth and splines are on the market.

Basic Specifications

The 8.8-inch differential feature six gear ratios: 3.08-to-1, 3.27-to-1, 3.31-to-1, 3.55-to-1, 3.73-to-1 and 4.10-to-1, according to Drivetrain. Gear ratios depend on the year and model of the Ford vehicle. The ring gear measures 8.8 inches in diameter with the single-piece case bolted with 10 7/16X20-inch threaded bolts. The pinion gear measures 1.626 inches in diameter with a 28-spline axle shaft through 2001, and 31 splines beginning in 2002.

Assembly Torque Specifications

The cover bolt assembly must be tightened to 28 to 38 foot-pounds. The ringer gear backlash requires .008 to .015 foot-pounds. Attaching the ring gear bolt to the case requires 70 to 85 foot-pounds of torque.


Ford used the 8.8-inch differential on the 1980s and 1990s four-liter Aerostar vans, Bronco and Explorer SUVs, four-liter compact Ranger pickups, full-size F-150 and F-250 pickups and Mercury Capris and Cougars. Contemporary F-Series and Rangers continue to use the 8.8-inch differential.

About the Author

Rob Wagner is a journalist with over 35 years experience reporting and editing for newspapers and magazines. His experience ranges from legal affairs reporting to covering the Middle East. He served stints as a newspaper and magazine editor in Saudi Arabia and the United Arab Emirates. Wagner attended California State University, Los Angeles, and has a degree in journalism.

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