1977/11/21 Caterpillar

Larger Diameter Holes Are Now Used In The Rocker Arm Shaft To Give More Oil Flow To Rocker Arm Bearings{1102}

Usage:

3304 Industrial and Marine Engines;
3306 Industrial, Marine and Truck Engines;
D4D, D5, D5B, D6C, D6D, D7G, 814, 627B and 627B Push-Pull Tractors;
815 and 816 Compactors;
920, 930, 941, 950, 951B, 951C, 955K, 955L, 966C, 977K, 977L and 980B Loaders;
518 and 528 Skidders;
12G, 14G, 120G, 130G, 140G and 120B Motor Graders;
561C, 561D, 571G and 572G Pipelayers;
215, 225 and 235 Excavators;
627B, 637D, 627B and 637D P.P. Scrapers

Description of Change: The oil inlet hole in the rocker arm shafts for the above models is now larger in diameter. This permits more oil to get to the rocker arm bearings to prevent possible failures. Also, the brackets for the rocker arm shaft are machined flat on top to prevent possible oil leakage between the washers of the bolts and the brackets.

Adaptable As: Direct replacement. The part numbers of the rocker arm assemblies did not change.

If desired, the oil inlet holes in the earlier rocker arm shafts can be drilled to a larger diameter. Formerly, the diameter size was .062" (1.57 mm). Now the diameter size is .094" (2.38 mm). Care must be taken if the rocker arm shaft is drilled, the shaft is made of a hardened steel.

It is more practical to install a new rocker arm shaft assembly, especially if bearing failures have been a problem.

Caterpillar Information System:

1977/11/21 New Crankshafts Do Not Have Lightening Holes And Lubrication Passages Connected Together{1202,1219}

1977/11/21 New Elbow Between Turbocharger And Air Inlet Manifold Has Hole For Ether Starting Aid{1058,1456}

1977/11/14 New Exhaust Manifolds Made Of Stronger Material{1059}

1977/11/14 Exhaust Valves With 30° Face Angle Now Used For Parts Service{1101,1103,1105}

1977/11/14 New Electric Starting Motor Has Longer Brush Life{1453}

1977/11/07 Precision Oil Pump Bearings Now Available{1304}

1977/11/07 Improved Crankshaft Main Bearings And Connecting Rod Bearings With Higher Strength Aluminum Alloy{1203,1219,1230}

1977/11/07 Crankshaft Support Groups Are Available To Measure Bent Crankshafts{0653,1202}

1977/10/31 Some Wobble Is Acceptable In Rubber Vibration Dampers For Crankshafts{1205}

1977/10/31 With New 5P7448 Adapter, Earlier Fuel Injection Valves And Nozzles Can Be Tested And Adjusted On The 5P4150 Nozzle Testing Group{0651,1254}

1977/10/31 New Governor Spring Changes Speed Regulation{1264,1286}

1977/10/31 New Hydraulic Flow Meter Has Many Improvements To Make It Easier, Faster And Safer To Use Than The Former Flow Meter{0651,5050}

1977/11/21 Improved Shaft Seal Material Used In All Vane-Type Hydraulic Pumps; Seal Kits Are Canceled{5055}

1977/11/21 New Housing And Impeller Assembly For Water Pump And Drive Group{1361}

1977/11/21 Add Chamfer To Cartridge Assembly Bearings To Prevent Oil Leakage{1052,1053}

1977/11/28 Reference Chart For Main And Connecting Rod Bearings{1203,1219,1230}

1977/12/05 Water Separators Needed On Machines And Engines In The Field With SMFS{1250,0336}

1977/12/05 New Oil Filter Base Has Reinforcement Around The Center To Prevent Possible Cracks{1306}

1977/12/05 Use The 5P8610 Auxiliary Fitting Group To Charge Two Suspension Cylinders At The Same Time{0690,7201}

1977/12/05 New Fuel Injection Valve Assembly Has Improved Internal Components{1254}

1977/12/12 Use Hardened Flat Washers With Diagonal-Split Hydraulic Flanges{5057,7553}

1977/12/12 New Coolant Tube And Regulator Housing Used With Water Cooled Exhaust Manifold Gives More Clearance For Hooks To Lift The Engine{1350,1355,1380}

1977/12/12 Excessive Oil Consumption Can Be Caused By Dirt In Air Inlet System Or By Flaking Of The Piston Compression Ring{1213,1215}

1977/12/19 Improved Mounting Base For Air Compressor{1065}