1982/04/05 Caterpillar

Reminder: Check Valve Lash Adjustment At Correct Intervals{1102}

Usage:

3406, 3408 Truck Engines

We have had some reports of valve failure on 3406 and 3408 Truck Engines. In some cases, valve failures are caused by loose bridge adjustment locknuts and/or too much valve lash. When the bridge adjustment locknuts are loose, it is possible for the valve lash to change.

Valve lash can also change if the locknut for the valve lash adjustment screw is loose. This can damage the valves and cause a valve failure.

On new or rebuilt engines, our recommendation is to measure and adjust the valve lash after 80 000 km (50,000 miles). Valve lash must be adjusted again at 160 000 km (100,000 miles). After that, valve lash must be adjusted at 160 000 km (100,000 mile) intervals.

Before the valve lash is adjusted, make sure the bridge adjustment locknut is tight. The complete procedure for valve lash adjustment is given in the 3408 Truck Engine Operation and Maintenance Guide, Form SEBU5673 and the 3406 Truck Engine Operation and Maintenance Guide, Form SEBU5595-01.

Caterpillar Information System:

1982/04/05 Conversion Of 49-State 3406 Truck Engine From 283 kW (380 hp) To 298 kW (400 hp) Arrangements{1000}

1982/04/05 Lubricant Recommendations Have Been Changed For Vehicular Products{0680,0374,0375,3004,1318,5060}

1982/03/29 Twisted Port Plate Can Cause Excessive Case Drain From Piston Pump Or Motor{5058,5070}

1982/03/29 New Regulator Group Increases Coolant Flow To Cab Heater, Prevents Overcooling{1355}

1982/03/29 Multi-Piece Wheel Rims; Caution Must Be Used{4202,4201}

1982/03/29 Flywheel Adapters For Dynamometer Testing{1156,0652}

1982/03/29 Location Of Sending Unit Changed To Improve Accuracy Of Water Temperature Indication{7453}

1982/03/29 Parts Book Changes{0374}

1982/03/22 Improved Plunger And New Spring Used In Mechanical Shutoff Group{7418}

1982/03/22 Use FT1614 Cover To Protect Center Shaft Assembly{0622,3305,3306,3302,3307}

1982/03/22 Correct Use Of 6V2023 Flow Check Adapter Group Is Important To Prevent Damage To An Engine{0651,0654,1250}

1982/03/22 Caterpillar Electric Starting Motors{1453,1407}

1982/04/12 Pressure Regulator Group Now Available For Parts Service{3152,3185,3166,3012}

1982/04/12 Use Correct Part Numbers For Main And Connecting Rod Bearings{1230,1203,1219}

1982/04/12 Lock Screw For Threaded Crown On Hydraulic Cylinders No Longer Used{5000}

1982/04/12 Make Sure Hydraulic Pumps Are Installed Correctly{5055,5070,5073}

1982/04/12 New Seals Improve Pressure Regulator Group{3185,3012}

1982/04/12 Use Correct Size Bolt To Install 5P9736, 6V2156 Or 6V2157 Link Brackets{0644}

1982/04/19 Improvements Made To 6V3000 Sure Seal Repair Kit{0611,1408}

1982/04/19 New Broken Link Spring Used In Governor{1264}

1982/04/26 Improved Relief Valve Guide Decreases Maximum Oil Pressure During Cold Weather Starts{1315,1304}

1982/04/26 Expansion Tank Changed To Permit Installation Of Water Level Gauge{1354,7470}

1982/05/03 6V4960 AC Current Probe Will Measure Current Easier{0652}

1982/05/03 Use New Special Instruction To Install 5P6595 Insert In Cylinder Liner Seats{1216,0621}