Mustang Lower Cowl Repair Panel (1967-1968) Installation Instructions

Tools Required:
  • Spot Weld Cutter
  • Drill
  • Cup Brush
  • 4 lb. Sledge Hammer
  • Small Chisel
  • Center Punch
  • 4 1/2 inch Grinder with Small Cutoff & Grinding Wheels
  • Self Tapping Screws
  • Welder
Install Difficulty:
  • Difficulty
  • Difficult Project
1. To start the installation of your new Mustang Lower Cowl Repair Panel, support the car at all four corners with jack stands (placed under the rockers).
2. Using a drill and a cup brush, work your way around the upper cowl panel so that you are revealing all of the spot welds.
3. Using a center punch, try to center on each spot weld and make a small indention.
4. Using the drill and a spot weld cutter, center the cutter over each spot weld and drill through the Mustang upper cowl vent grille, being careful not to drill through the lower cowl panel.
5. Continue to drill out the more than 100 spot welds on the upper cowl panel. Remember that there are two rolls of spot welds in the lower windshield/top edge of upper cowl panel.
6. Drill out the spot welds that hold the Mustang fender apron rear extensions on.
7. Using a small chisel and a hammer, slowly work around the edges of the upper cowl panel. Make sure that all of the spot welds are loose, then slowly pry the upper cowl panel off. Be careful not to distort the upper or lower cowl.
8. Remove the upper cowl panel and set it aside.
Mustang Lower Cowl Repair Panel Install Image
9. Inspect the cowl hat area to make sure that the repair panel will be sufficient to repair all of the damage.
10. Drill holes along the outside edge of the replacement cowl panel to act as plug weld holes.
11. Lay the replacement panel over the area that is being replaced and scribe the underlying area, using the chisel to act as a guide for where the replacement panel will fit.
12. Drill out the lower cowl panel spot welds around the perimeter (up to your scribe line on firewall and windshield channel).
Mustang Lower Cowl Repair Panel Install Image
13. Cut the Mustang lower cowl panel three inches from the mark, towards the outer edge of the cowl. Be careful to not cut through anything but the lower cowl.
Mustang Lower Cowl Repair Panel Install Image
14. Remove all of the old metal.
15. Work the replacement cowl panel in underneath the remaining pieces of the lower cowl until they line up properly on the sides, windshield channel and Mustang firewall. Make sure that the panel is laying under the original cowl panel and that it is overlapping (which is the reason for cutting three inches inside of the scribe line).
Mustang Lower Cowl Repair Panel Install Image
16. Using the self tapping screws, secure the replacement panel to the remnants of the lower cowl and screw it in place.
17. Using the grinder and cutoff wheel, cut through both panels.
18. If your cuts were correct, you should have a perfect fit between the replacement panel and the original panel that you can now butt weld (lap welding is not recommended, as water will pool here).
Mustang Lower Cowl Repair Panel Install Image
19. Weld the two pieces together and proceed to plug weld the new Mustang lower cowl repair panel to the firewall flange and the windshield channel. Remember to dress the welds appropriately.
Mustang Lower Cowl Repair Panel Install Image
20. Lay a bead of Mustang seam sealer over the welds and smooth it out.
21. Reinstall the upper cowl panel and spot weld it back to the lower cowl and windshield channel, using the holes that you created when you drilled the spot welds out.
22. Congratulations! You have just installed a new Mustang Lower Cowl Repair Panel.
Mustang Lower Cowl Repair Panel Install Image