Symptoms
The truck darts and wanders on the highway, needs constant correction, shimmies after bumps, or sits visibly lower on one side at the front.
The fix, step by step
- Wild Horses says about 90 percent of wandering early Broncos have incorrect caster, and its spec is +4 to +9 degrees.
- Lifting the truck moves caster negative, which is why offset C-bushings exist; 7 degrees is the standard.
- Support the frame on stands (not the axle), unbolt the radius-arm caps and fit the new C-bushings the right way up, following the 'front bottom' and 'rear bottom' markings.
- A bushing installed upside down changes caster and can make the truck lean.
- If it still leans, Brian Cooke's fix is to check that both radius arms touch a level floor at the same time and reseat the C-bushings by retightening the cap bolts in a different order.
- For shimmy and death wobble, Wild Horses names worn upper track-bar bushings as the number one culprit.
Tools & part numbers
- Jack stands under the frame
- floor jack
- socket set and torque wrench
- angle finder for caster
Where to buy the parts
C-bushing kit, 7°, 1966–75, 14 piecesBronco Graveyard ↗Amazon ↗
C-bushing kit, 7°, 1976–77, 14 piecesBronco Graveyard ↗Amazon ↗
Track-bar bushings, 1966–75Bronco Graveyard ↗Amazon ↗
Track-bar bushings, 1976–77Bronco Graveyard ↗Amazon ↗
Hunting a used or discontinued part? Search eBay Motors for Ford Bronco (1966–1977) parts →
Rated for a competent home mechanic with a decent tool kit. Confirm torque figures, fluids and procedures against the factory service manual for your VIN, support the truck on stands rather than a jack, and work at your own risk (disclaimer). Some parts links are affiliate links, which pay us a small commission at no cost to you.