Operation CHARM: Car repair manuals for everyone.

Standard Procedure - Frame Service

NOTE: As of October 2007, the manufacturer has updated their position on the heating of components during repair. Refer to the statement here: Use Of Heat During Repair

FRAME STRAIGHTENING


When necessary, a conventional frame that is bent or twisted can be straightened by application of heat. The temperature must not exceed 566 degrees C (1050 degrees F). The metal will have a dull red glow at the desired temperature. Excessive heat will decrease the strength of the metal and result in a weakened frame. Welding the joints around riveted cross members and frame side rails is not recommended. A straightening repair process should be limited to frame members that are not severely damaged. The replacement bolts, nuts and rivets that are used to join the frame members should conform to the same specifications as the original bolts, nuts and rivets.

FRAME REPAIRS

DRILLING HOLES

Do not drill holes in frame side rail top and bottom flanges, metal fatigue can result causing frame failure. Holes drilled in the side of the frame rail must be at least 38 mm (1.5 in.) from the top and bottom flanges. Additional drill holes should be located away from existing holes.

WELDING

Use MIG, TIG or arc welding equipment to repair welded frame components. Frame components that have been damaged should be inspected for cracks before returning the vehicle to use. If cracks are found in accessible frame components perform the following procedures.
1. Drill a hole at each end of the crack with a 3 mm (0.125 in.) diameter drill bit.
2. Using a suitable die grinder with 3 inch cut off wheel, V-groove the crack to allow 100% weld penetration.
3. Weld the crack.

Fig. 3:




4. If necessary when a side rail is repaired, grind the weld smooth and install a reinforcement channel (Fig. 3.) over the repaired area.

NOTE: If a reinforcement channel is required, the top and bottom flanges should be 0.250 inches narrower than the side rail flanges. Weld only in the areas indicated (Fig. 3).

FRAME FASTENERS

Bolts, nuts and rivets can be used to repair frames or to install a reinforcement section on the frame. Bolts can be used in place of rivets. When replacing rivets with bolts, install the next larger size diameter bolt to assure proper fit. If necessary, ream the hole out just enough to sufficiently receive the bolt. Hardened conical-type washers are preferred over the split-ring type lock washers. Grade-8 bolts are recommended for frame repair. Grade-3 and grade-5 bolts or softer should not be used. Tighten bolts/ nuts with the correct torque, and Refer to Body and Frame / Specifications / Dimensions for tightening information.