SHAFT-AXLE 0551806 - Caterpillar

Repair Procedure
Use AWS E7018 electrodes or equivalent weld rod for all welding.
1. Fabricate the left hand and right hand blocks to the dimensions shown in Illustrations 1 and 2. Use 40 mm (1.6") thick structural steel with 240 MPa (34,700 psi) minimum yield strength and with 430 MPa (62,700 psi) minimum tensile strength.
Illustration 1. Detail of LH block.
Illustration 2. Detail of RH block.2. Fabricate two plates to the dimensions shown in Illustration 3. Use 10 mm (.4") thick structural steel with 355 MPa (51,500 psi) minimum yield strength and with 490 MPa (70,500 psi) minimum tensile strength.
Illustration 3. Detail of new steering stop plate.3. Articulate the truck to full lock. Put the transmission in neutral. Apply the parking brake and shut off the engine.
There is not enough clearance in the area of the oscillating hitch for a person to work when the truck turns. Severe injury or death from crushing could occur if the truck is turned while a person is working in the area of the oscillating hitch. Connect the steering frame lock link (anti-articulation stop) before working in this area. If the lock link (anti-articulation stop) can not be installed for any reason, take precautions to be certain that no other person can start the engine and operate the truck.
4. Disconnect the extended steering cylinder from the hitch lug and swing it out of the way.5. Protect the surrounding area and remove the existing steer stop plate along the existing welds as shown in Illustration 4. Use a cutting torch or an equivalent method.
Illustration 4. Flame cut these welds to remove existing plate.6. Grind the area smooth making sure all paint is removed. Grind a 12 mm (.5") × 45° chamfer on the outer edge of the backplate to the dimensions shown in Illustration 5.
Illustration 5. Adding reinforcement for steering stop.7. Locate the appropriate block in position as shown in Illustration 5 and tack weld in place.8. Make sure that face (B) of the block is level with face (A) of the hitch top plate. Grind face (B) of the block as required to achieve this condition, then finish welding the block in position as shown in Illustration 5.9. Tack weld the new steering stop plate in the position shown in Illustration 6. After the plate is correctly positioned, complete the weld as shown. Build up the weld flush at the bottom of the plate as shown in the insert in Illustration 6 and blend the weld smoothly into the steering lug. Be sure there is a smooth blend to the vertical weld at the outer edge of the backplate as shown. Finish grind the weld if necessary to obtain a smooth transition.
Illustration 6. Locate and weld new steering stop plate.10. Install the steering cylinder back in position.11. Repeat the procedure for the other side of the truck, then paint the repaired areas.