1996/05/09 Caterpillar

New Stronger Cylinder Head Bolts Used{1100}

Usage:

3406 (6TB, 90U) Industrial;
3406 (2WB, 4RG, 4JK) Generator Set;
3406 (4TB) Marine;
G3406 (4FD, 1RK) Engines

Description of Change: New cylinder head bolts are used in these commercial engines. The new stronger bolts meet or exceed SAE Grade 8 tensile strength and proof load tests. The 3/4- 16 UNF threads are rolled into the bolts after heat treat. The new bolts can be identified by the standard "Grade 8" bolt head marking of six equally spaced marks radiating outward on the top of the 12 point bolt head. See the illustration.

Identification "Marks" on top of bolt heads on the new 124-1855 Cylinder Head Bolt.

Adaptable To: The new 124-1855 Bolt [3/4- 16 UNF thread, 194.0 mm (7.64 in) long] replaces the former 9X-8904 Bolt. Twenty 124-1855 Bolts are used on each cylinder head. The 6 rocker arm bracket bolts remain unchanged. The new cylinder head bolts are effective with:

*3406C (90U19998, 6TB15397) Industrial

*3406C (4TB5051) Marine

*3406C (2WB16660, 4RG2510, 4JK196) Generator Set

*G3406C (4FD1042, 1RK61) Engines

The new cylinder head bolts are adaptable to all earlier 3406 Engines.

Caterpillar Information System:

1996/05/09 Torque Check Necessary For Front Support Bracket Bolts When Damper And Pulley Are Removed{1153}

1996/05/09 Radiators Made With Improved Brass Composition To Add Strength At Crimp Joint{1353}

1996/04/15 Check Valve May Be Needed To Accurately Measure Engine Return Fuel Flow{0706,0774,0782}

1996/04/15 Repair Kits Available For Prelube Pump Groups{1319}

1996/04/15 Remanufactured Cylinder Head Groups Available{1100}

1996/04/15 Engine Configuration And Monitoring System Parameter Programming At Initial Startup{1900,1901}

1996/04/15 New Stainless Steel Plate Prevents Formation Of Rust Within Air Inlet And Exhaust System{1063}

1996/04/15 New Gasket Kits Available{1052,1059,1063,1100,1150,1201,1216,1304,1361,1378,1380}

1996/04/15 129-0372 Primary Fuel Filter/Water Separator Assembly{1260,1263}

1996/04/15 New Gasket For Engines With Water Cooled Exhaust Manifolds{1059}

1996/04/15 New Valve Cover Gasket Helps Prevent Oil Leaks{1107}

1996/03/19 New Liquid Detector Group Used In Jacket Water Low Level Liquid Detector Group{7421}

1996/05/09 New Components In Camshaft Groups Provide Increased Lubrication To Thrust Washer Assembly{1210}

1996/05/09 Oil Drainback Holes Changed In New Piston Crown{1225}

1996/05/09 New Integral Seal In Water Lines Groups Helps Prevent Coolant Leaks{1380}

1996/05/09 New Extension For Electronic Ignition System (EIS) Transformer Groups{1409}

1996/05/09 New High Temperature Resistant Seal Group And O-Ring Seal Used In Water Pump Groups{1361}

1996/05/09 Woodward Control Assemblies Have Changed Part Numbers To Provide The CE Marking For Electromagnetic Compatibility (EMC) Directives{1264}

1996/05/09 New Software For The Customer Communication Module{1926}

1996/05/09 New Programmable Logic Control With In-Phase Monitor For Contactor Type Automatic Transfer Switches{4469}

1996/06/12 Check Cooling System If Exhaust Manifold Or Cylinder Head Gasket Is Damaged{1350}

1996/06/12 Part Number And Application Guide For Oil, Fuel And Transmission Pressure Senders And Water Temperature Senders{1924}

1996/06/12 Troubleshooting Information{7569}

1996/06/12 Formed Rubber Hose Replaces Cast Iron Elbow In Radiator Groups; Be Sure To Use The Correct Water Temperature Regulator{1353}