How to Change 5.8L Ford OBS Bronco Spark Plugs

In this video, Landan explains the process of how to change spark plugs in a 1992-1996 OBS Ford Bronco equipped with a 5.8L Windsor small block Ford engine. This process would also be applicable to the 1992-1993 Ford Lightning and other 5.8L equipped Ford trucks and vehicles.

• Fits: 1992-1996 Bronco
• Skill Level: Beginner
• Install Time: 1 Hour

Product Links:

• 1992-1996 Bronco Spark Plugs

Tools Required:

• 5/8" spark plug socket

• Socket extensions

• Torque wrench (optional)

• Anti-seize compound

• Dielectric grease

• Compressed air

• Spark plug gapping tool

• New spark plugs

Removal Steps

1. Gap the New Spark Plugs

• Set spark plug gap to 0.042–0.046 in.

• Example used: 0.044 in (middle of the range).
  

2. Work One Cylinder at a Time

• Remove one spark plug wire and label it so you don’t mix them up.

• Driver-side cylinder numbers: 5, 6, 7, 8 (front → back).
  

3. Clean the Area

• Use compressed air to blow dirt/debris away from the spark plug hole before removing the plug.

4. Remove the Old Spark Plug

• Use the 5/8" spark plug socket and extension to loosen and remove the plug.

5. Prepare the New Plug

• Apply a small amount of anti-seize to the threads and taper of the new plug.

6. Install the New Plug

• Thread the plug in by hand first to avoid cross-threading.

• Tighten:

  • Torque spec: 10–15 ft-lbs

  • If using anti-seize, torque closer to 10–11 ft-lbs.

7. Reinstall Plug Wire

• Add a pea-sized amount of dielectric grease inside the wire boot.

• Push the wire back onto the correct spark plug.

8. Repeat for Remaining Cylinders

• Continue the same process for all plugs.

9. Passenger Side Tips

• Passenger side has less space.

• Move vacuum lines out of the way to create room.

• The HVAC box may block a torque wrench, so tighten carefully by feel if needed.

10. Verify Plug Wire Order

• Engine firing order: 1-3-7-2-6-5-4-8.

• Make sure wires are on the correct cylinders and not touching exhaust manifolds/headers.

11. Final Check

• Start the vehicle and take a short drive.

• Record the date and mileage for maintenance tracking.