Early Bronco Ford 9-inch Differentials & Lockers

Early Bronco Ford 9-inch Rear Differential & Locker Options Explained

Upgrading the rear differential on your Early Bronco is one of the best ways to boost performance, both on and off-road. The Ford 9-inch rear axle is legendary in the off-roading world, but choosing the right differential or locker can make all the difference in how your Bronco handles rough terrain. Whether you're sticking to stock options or upgrading to more advanced locking differentials, this guide will help you explore the pros and cons of each option and find the perfect fit for your rig. Let’s break down your choices.

Factory 66-77 Ford Bronco Differential Options

Open Differential

• Transmits power through one axle
• Great for street driving, but not ideal for off-roading
• Can leave you stuck when traction is limited

Limited Slip Differential

• Uses internal clutch packs to distribute power to both axles
• Allows “slip” when turning, so the outside wheel turns faster
• Can slip off-road when you need power at both wheels
• Quiet and mostly trouble-free
• Requires finesse to get the most out of it off-road

Early Bronco Locking Differential Upgrades

Detroit Locker / Yukon Grizzly Locker

• Fully automatic locking differentials
• Ideal for hardcore off-roaders
• Low maintenance – install and forget
• Directs power equally to both wheels, providing excellent traction

Selectable Lockers (ARB Air Locker)

• Engaged with a switch, giving you control
• Open when not engaged, offering smooth, quiet street performance
• Switch on for full locking power off-road
• Time-tested in extreme off-road environments
• Engages quickly with compressed air, locking the differential for instant torque to both wheels
• Disengages with a flip of the switch when no longer needed

Each option has its own strengths depending on your driving style and off-roading needs, making it easy to customize your Early Bronco for any adventure.