VALVE GP 1135232 - Caterpillar

Introduction
The problem that is identified below does not have a known permanent solution. Until a permanent solution is known, use the solution that is identified below.Problem
The 300-5440 lower swing frame tapered pin on certain Center Pivot and Side Swing Backhoe Loaders could fail in the field. Effected Frames Gp - Swing include 314-3988, 251-4519, and 251-4520.
Illustration 1 g02702996
Failure results in cracking of the pin around the under-cut area of the threaded section (A). In extreme cases, the pin can break through, effecting retention of the swing frame.Solution
This bulletin provides the best practices for the inspection and installation of the tapered lower swing frame pin used on the listed machines. Use the bulletin along with Disassembly and Assembly, "Swing Frame - Remove" and Disassembly and Assembly, "Swing Frame - Install" for your machine. The following additional procedure will aid in preventing future failures from occurring due to tapered pin loosing torque.
Inspection of the tapered bore located in the lower swing frame.
Obtain a new tapered pin and paint the tapered surface of the pin with machinists blue.
Clean the tapered bore of the swing frame and the pin to ensure that there is no grease or other contaminates in the bore. If rust or residual paint is found, remove with a Scotch-Brite pad. Use a good solvent that removes grease and does not leave any residue. Alcohol wipes also work well. Any grease left on the pin or in the bore can affect the joint and may not let the pin set in the bore correctly.
Assemble the pin in the swing frame and torque the retaining