1977/01/24 Caterpillar

Same Valve Camshaft Assembly Used On Direct Injection Engines Now Used On Engines That Have Precombustion Chambers{1210}

Usage:

3406 Truck, Industrial, Marine and Vehicular Engines Equipped with Precombustion Chambers

Description of Change: The valve camshaft assembly used currently on 3406 Engines equipped with a direct injection fuel system is now also used on the above engines. This change will decrease the number of parts that must be kept on hand and improve parts replacement service.

Adaptable As: The new 6N4991 Camshaft Assembly is a direct replacement for the former 6N1405 Camshaft Assembly which is canceled.

The 6N4991 Camshaft Assembly was first used on 3406 Engines with direct injection, starting with Serial Numbers 92U3187 and 90U514. The 6N4991 Camshaft Assembly was first used on 3406 Engines with precombustion chambers, starting with Serial Numbers 92U7387, 90U2496, 91U549 and 70V3431.

INSTALLATION: When the 6N4991 Camshaft Assembly is installed, it is our recommendation that you install new 6N4589 Valve Lifters and 6N6872 Spring Clips.

Caterpillar Information System:

1977/01/24 Adapter For Disassembly And Assembly Of Turbocharger Cartridge{0620,1053}

1977/01/24 Exhaust Valve Guides With A Counterbore Are Now Available{1104}

1977/01/24 Exhaust Manifold Coupling With A Slip Fit Now Used Instead Of A Coupling With Piston Rings{1061}

1977/01/24 Drain All Coolant From Engines Before Shipment For Remanufacturing{0355,1350}

1977/01/17 New Water Temperature Regulator Has A Closer Fit At The Valve Seat To Keep Leakage At A Minimum{1355}

1977/01/17 New Flywheel Assemblies Are Available For Use With Spicer Transmissions{1156}

1977/01/17 New Tie Bars Improve Stability Of The Fuel Injection Test Bench{0652}

1977/01/17 SIRS Component Code List{0331}

1977/01/17 New Special Instruction For Troubleshooting 5P2150 Engine Horsepower Meter{0651,1250}

1977/01/17 Blades For Hose Saw Cut Off Group Must Now Be Sent To New Address To Be "Resharpened"{0664}

1977/01/17 Improved Main And Connecting Rod Bearings Have Aluminum Alloy With More Strength{1230}

1977/01/17 Removal Of Bolts With Metal Locks Easier With New Sockets{0610}

1977/01/24 Coupling With A Slip Fit Now Used At Turbocharger Exhaust Outlet Instead Of Coupling With Piston Rings{1061}

1977/01/24 New Cylinder Liners{1216}

1977/01/24 Lightening Holes Not Drilled In Some Crankshafts{1202}

1977/01/31 New Disconnect Switch Assembly Has Better Resistance To Corrosion{1411}

1977/01/31 Improved Crankshaft Main Bearing With Higher Strength Aluminum Alloy{1203}

1977/01/31 New Remote Control Switch Assembly For Electric Hydraulic Pumps{0621,0623}

1977/01/31 Transportation Notice Plate Is No Longer Needed For Pressurized Nitrogen Cylinders{7557}

1977/01/31 Low Emission Truck Engines With Exhaust Gas Recirculation (EGR) Systems{1050}

1977/02/14 Correct Use Of Plugs In Drain Holes Of Hydraulic Pumps That Have Two Seals On The Shaft-Use A Plug In Drain Hole Except With Water Glycol Systems{5055,5073}

1977/02/14 New 5P7307 Engine Turning Tool Group Fits All Engines{0611}

1977/02/14 Test Used Fuel Nozzles Before You Install New Nozzles; Tips On Test Procedures{1254,0651,0336}

1977/02/14 Diesel Fuel Recommendation Expanded{1280}