Mustang 3-Point Retractable Seat Belts (1965-1973) Installation Instructions

Tools Required:
  • Drill
  • Drill Bit Set with 1/8-inch & 1/2-inch bits
  • 5/8-inch Wrench & Socket
  • Metal Punch
  • Hammer
  • 1/2-inch Deep Well Socket & Extension
  • 3/4-inch Wrench
  • Rivet Gun
Install Difficulty:
  • Moderate
  • Moderate Project
1. Installation of your new 3-Point Retractable Seat Belts may be easier if the front seats are removed. To do this, locate the four holes underneath the car that allow access to the seat nuts. Pictured is one of the holes. Remove the nuts with a 1/2-inch deep well socket on an extension.
Mustang 3-Point Retractable Seat Belt Install Image
2. Remove the existing Mustang seat belt using a 5/8-inch wrench to remove their attaching bolts.
3. The new buckle can immediately be installed using the existing anchor in the transmission tunnel for the buckle. Pop the black plastic cover off the bolt access hole on the new buckle with a flat head screw driver. Use one of the shorter 7/16-inch bolts supplied in the hardware kit and tighten down with a 5/8-inch wrench. Alternatively, you can use the original bolts.
Mustang 3-Point Retractable Seat Belt Install Image
4. The top mounting point of the shoulder belt will mount to the top of the door post, just below the front corner of the quarter window. The retractor needs to be mounted on the floor directly perpendicular to the upper mount. This ensures proper function of the seat belt from the retractor. This also means that a new hole must be drilled for a new anchor point, and the original anchor point will not be used. Additionally, if the retractor is mounted in the original anchor point, it will not allow the seat track to slide all the way back. The existing mounting point can be plugged with a fine thread 7/16-inch bolt. There will be extra bolts in the hardware kit that can be used for this purpose.
5. Use one of the 90 degree corner brackets to mark the location of the hole. The short side of the bracket goes on the floor. When mounted to the rear floor pan in the area shown, this will go through the rear torque boxes and prove a very solid and rigid mounting point. Make sure the area beneath this point is free of any fuel or brake lines.
Mustang 3-Point Retractable Seat Belt Install Image
6. Drill a hole through the Mustang floor pan. Start with a small bit to make a pilot hole, using a 1/8-inch bit, then work up the bit size through several steps, ending with a 1/2-inch bit.
Mustang 3-Point Retractable Seat Belt Install Image
7. Next, lay the Mustang seat belt out as shown to ensure it is not twisted. The end of the belt with the long skinny slotted bracket sits behind the retractor.
Mustang 3-Point Retractable Seat Belt Install Image
8. Use one of the short 7/16-inch bolts and a washer supplied in the hardware kit to secure the retractor and the slotted bracket to the long end of a 90 degree bracket. Secure with one of the supplied nylon lock nuts, but don't tighten down all the way—it can be completely tightened after the installation. This uses a 5/8-inch wrench.
Mustang 3-Point Retractable Seat Belt Install Image
9. Set the Mustang seat belt retractor and bracket in place in the car, lined up with the new hole drilled in the rear floor pan. Pass one of the supplied longer 7/16-inch bolts through it. On the underside of the car, add one of the large anchor washers, then a small washer, then a nylon insert lock nut. Tighten down with a 5/8-inch wrench. The nut in this picture is not tightened down yet.
Mustang 3-Point Retractable Seat Belt Install Image
10. Use one of the threaded T anchors and set the flat part of the anchor in the B pillar door jamb as high in the jamb as possible, while still having full flat contact of the anchor against the jamb. Make a mark off to the side in the jamb that lines up with the threads in the center of the anchor.
11. Using a metal punch, make a small punch centered in the jamb next to the mark made in Step 10.
12. Drill a hole all the way through the jamb and interior panel, starting with a small 1/8-inch bit to make a pilot hole. Step up the bit size through 2 or 3 steps to 1/2-inch.
13. Insert the Mustang seat belt bolt anchor plate as shown.
Mustang 3-Point Retractable Seat Belt Install Image
Mustang 3-Point Retractable Seat Belt Install Image
14. Next place the nylon spacer over the threads as shown.
Mustang 3-Point Retractable Seat Belt Install Image
15. Remove the plastic cover from the shoulder mount for the Mustang seat belt.
16. Remove the flimsy plastic bushing from the hole in the shoulder mount (shown in picture below), and place the shoulder mount onto the nylon spacer on the threaded stud.
Mustang 3-Point Retractable Seat Belt Install Image
17. Thread the large narrow lock nut onto the threaded stud. This is tightened with a 3/4-inch wrench. Don't completely tighten.
18. At this point, if everything looks like it fits fine, the anchor plate can be permanently mounted to the door jamb with the supplied 5/32-inch rivets. Use a 5/32-inch drill bit to drill the holes for the rivets.
19. Finish tightening the lock nut, and place the plastic cover back on the shoulder mount.
20. The 3-Point Retractable Seat Belts is now completely installed.
Mustang 3-Point Retractable Seat Belt Install Image