1977/01/24 Caterpillar

Exhaust Valve Guides With A Counterbore Are Now Available{1104}

Usage:

D353, D379, D398, D399 Engines;
D9 Tractors;
594 Pipelayers

Reference: "Modification of Valve Guides To Prevent Exhaust Valve Damage," April 12, 1976, Service Magazine, page 10.

Description of Change: A new guide is available which has a counterbore at the bottom to give more clearance at the end nearest the valve head. When deposits cause the valve stem to become larger, the added clearance still permits the exhaust valve to operate freely to prevent valve damage.

The reference article tells how a counterbore can be added to exhaust valve guides until a new guide is available.

The modification given in the reference article for the former exhaust valve is still good and can be used if the new exhaust valve guides are not installed.

Adaptable As: Direct replacement.

Caterpillar Information System:

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}

1986/12/22 New Torque Control Group Used In Governor And Fuel Injection Pump Group{1264}

1986/12/22 New Oil Level Gauges (Dipsticks) With "Full Range" Used{1326}

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

1977/01/24 Same Valve Camshaft Assembly Used On Direct Injection Engines Now Used On Engines That Have Precombustion Chambers{1210}

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}