1994/02/01 Caterpillar

New Turbocharger Models Have Left-Hand Threads On Compressor Nut And Turbine Shaft{1053,1052}

Usage:

3116 Truck Engines

All new and remanufactured turbochargers for 3116 Truck Engines are changing to left-hand threads in the compressor nut and on the turbine shaft. When this change is made, the turbocharger and cartridge part numbers will not change. However, the turbocharger model numbers on the turbocharger name plate will change as shown in the chart. There will be no service parts released below the cartridge group for the left-hand thread models. Complete turbochargers and cartridge groups will continue to be offered for service.

Before attempting to repair a model C2 turbocharger, check the model number on the turbocharger nameplate and verify that the model number does not contain an "L". If the model number does contain an "L", do not attempt to service this turbocharger below the cartridge level. The reasons for not servicing the cartridge groups are:

* The turbocharger shaft is easily bent during disassembly and assembly which can result in additional failures.

* The rotating assembly is balanced by the supplier and disassembly can unbalance the assembly.

* Left hand threads on nut and turbine shaft are being introduced. This will help prevent the compressor retaining nut from loosening and allowing a compressor wheel rub.

Service parts will remain available for cartridges and turbochargers with right-hand thread compressor nuts and turbine shafts. All current parts manuals and service parts systems identify parts for right-hand thread turbochargers. These parts may not work properly in left-hand thread turbochargers. However, right-hand thread turbochargers and cartridge groups will be serviced with left-hand thread turbochargers and cartridge groups.

These changes will provide a more reliable turbocharger for the customer. Remanufactured cartridges will provide a low cost service option. Additional remanufactured cartridge groups are being released to provide 100 percent coverage of remanufactured cartridges for the S2 turbochargers.