Improper welding techniques often result in weld and/or frame failures. The following information describes some potential areas of difficulty and provides some general guidelines for successful frame welding. This information only pertains to steel rails that are not heat treated.
Most weld failures occur at the end of the weld in the areas of the frame that are under high levels of stress. The elimination of the ends of a weld may reduce failures. Eliminate the ends by making a hole or a slot in the part that will be attached and using a fillet weld around a slot or a plug weld. Do not leave a notch at the end of a weld. For a guide to the diameter and the depth of plug welds by the thickness of the welded material, refer to Welding Table . In most cases, the elimination of the ends of the welds will result in less welding, lower costs, and a more successful weld.
Adhere to the following instructions while performing a welding procedure:
| • | Do not overweld, especially in areas of the frame that receive a high concentration of stress. |
| • | Weld any small cracks in the crossmember. Refer to Frame Repair . |
| • | Refer to Electrode Table to determine the appropriate electrodes to use for a particular welding procedure. |
Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.
| • | Disconnect the vehicle battery. |
| • | Do not use any oxyacetylene welding equipment. |
| • | Use electrodes with a smaller diameter. |
| Make several passes. Do not make any more passes than necessary. |
| • | Only use as much heat as is necessary to achieve adequate penetration. |
| • | Make sure that the weld is free from craters and undercuts. |
| • | Remove the scale from each successive pass. |
| • | Grind the surface of the weld flush with the parent material when repairing a crack. |
| • | Do not weld across the flanges when mounting any accessories. |
| • | Do not weld within 19 mm (0.75 in) of a flange when mounting any accessories. |
| • | Leave at least 6 mm (0.23 in) between the end of a weld and the edge of the part. |
| • | Do not weld the cast brackets to the frame. |
| • | Do not weld together the flanges of any cracked reinforcements and base rails. |
| • | Do not attach the ground cable to the engine. Connect the welding machine ground cables as close to the working area as possible. |
| • | Keep the welding cables away from the vehicle wiring. Avoid any direct contact between the welding cables and any part of the vehicle. |
