Section 01-01: Underbody
1994 Mustang Workshop Manual
ADJUSTMENTS

Welding

 CAUTION: Disconnect the battery ground cable (14301) before using any electrical welding equipment.

Perform all welding using Rotunda MIG (Metal Inert Gas) Welder 066-01210 or equivalent, and welding wire meeting AWS-E-70S or equivalent, and welding wire meeting AWS-E-70S specifications.

When performing oxyacetylene welding or brazing, protect the adjacent areas with heat insulation compound.

Because more extensive panel deformation results from oxyacetylene welding than from MIG welding or spot welding, perform sectional welding using MIG welding or spot welding equipment only.

Perform spot welding operations in locations that are inaccessible with spot welding tongs using the hole weld method. Drill or punch 5mm (0.2 inch) holes in one side of the flange and weld and add filler material.

Varying factors determine plate thickness, panel design, cross-sectionals and sizes, joining method, welding method, and welding locations during manufacturing. To apply the most suitable repair method, therefore, it is most important to completely understand the body design, concept, and construction.

In a monocoque body shell, the structural elements supporting the transmission and suspension are welded to the bodywork. Every frame, member, and outer panel is designed to offer the maximum protection in the event of a collision. It is very important, therefore, that a repaired part meet the same standards as those installed on the new vehicle.

It is essential that repair welds, particularly on load-bearing parts or parts contributing to the strength of the assembly, are equivalent to the originals in size, type, and strength.

 

Low-Alloy Steel Components

 CAUTION: Disconnect the battery ground cable before using any electric welding equipment.

  1. Because of associated high heat buildup, do not use oxyacetylene when welding high-tensile or high-strength, low-alloy steel components. Use spot, MIG, or arc welding. During MIG or arc welding, use a temperature-indicating crayon to ensure that the temperature does not exceed 750°C (1400°F).
  1. Replace spot-welded components by spot welding where possible. If spot welding equipment is not available, or if the location is not accessible, puddle weld the panels.
  1. Use MIG welding rather than conventional arc welding when welding high-strength, high-tensile, or conventional mild steel. Use 0.8mm or 0.9mm diameter wire and conform to Classification AWS A5. 18-69, E70S-6 or E70S-4. MIG welding is also known as GMAW (Gas Metal Arc Welding).
  1. Perform conventional arc welding using 2.5mm diameter rods conforming to Classification AS1552-1973, E4841 or AWS A5.1-78, E7014.

    When cutting salvage or repairable components, use a grinding disc, air chisel, or metal cutting saw.

    All welding should be done with a Rotunda MIG Welder 066-01210 or equivalent, with welding wire meeting AWS-E-70S Specification.