Do Not Use Heli-Coils® To Repair Rocker Arm Assemblies On 5.4" Bore Engines {1123}
Usage:
D346, D348, D349 Engines
Reference: Service Magazine; December 22, 1986; Page 13; "Use Heli-Coils To Repair 5.4" Bore Engine Rocker Arm Assemblies."
Caterpillar now recommends NOT to use Heli-Coils to repair threads in the rocker arm assemblies on the above engines. Field experience indicates that the rocker arms continue to wear even after Heli-Coils have been installed. Inspect the rocker arm assemblies either when the valves are adjusted or at overhaul. Use the "Procedure To Check For Excessive Thread Wear" in the reference article. If excessive thread wear is found, replace the rocker arm assembly.
Caterpillar Information System:
1988/12/19 New Piston Body Assemblies Used {1214}
1988/12/19 Check Assembled Dimension For Rack Lever Travel If Governor Housing Assembly Is Replaced {1264}
1988/12/19 New Camshafts Used; Camshaft Installation Kits Available {1209,1210}
1988/12/19 New Detent Group Available For Hoist Control Valve {5051}
1988/12/19 New Axle Differential Group Used {3258}
1988/12/19 New Latch Used For Engine Side Doors {7263}
1988/12/19 Stronger Spacers Can Be Used On Stabilizer Street Pads {6505}
1988/12/19 New Brake Disc Assemblies, Axle Lubricant Reduce Brake Chatter {3278,4255}
1988/12/19 New Circle Drive Gerotor Motor Groups Provide Higher Torque To Circle Drive {5082}
1988/12/19 Cold Weather Readiness Checks {1456,1250}
1988/12/19 New Material Used For Rotating Seal Rings In Some Power Shift Transmissions, Steering Clutches And Torque Converters {3101,3150,4100}
1988/12/12 Oil Cooler Bypass Elbow Changed To Prevent Bypass Valve Seizure{1314,1318}
1988/12/19 Operation Of Differential Lock {3264}
1988/12/19 Twelve Bolts Used In Drum Support Bearing Retainer {8227}
1988/12/26 New Muffler And Pipe Used; Low Idle Increased {1061,1062,1264}
1988/12/26 Check Load Height Before Transporting Machines {7500}
1988/12/26 Enlarge Lower Hook Openings On Three-Point Hitch Quick Coupler Group {7120}
1988/12/26 Check Bore Length Of Gear And Sleeve Before Assembling In Transmission {3061}
1988/12/26 New Gas Cylinder Used In Operator's Console {7451}
1988/12/26 Improved Boom Cylinder Lines {5057,5456}
1988/12/26 Shorter Bolts Used For Bolt-On Cutting Edges {6801}
1988/12/26 Be Sure Breathers Are Connected When Winches Are Installed {5163}
1988/12/26 New Governor Control Cable Used {1265}
1988/12/26 New Coolant Flow Switch Available {7422,7425}