Usage:
The turbocharger is mounted to the engine exhaust manifold. All the exhaust gases from the diesel engine pass through the turbocharger.
The exhaust gases enter the turbine housing and are directed through the blades of a turbine wheel, causing the turbine wheel and a compressor wheel to rotate.
Filtered inlet air from the air cleaners is drawn through the air inlet of the compressor housing by the rotating compressor wheel. The air is forced to the inlet manifold of the engine and is compressed by action of the compressor wheel.
This is a cross section of the turbocharger. The components identified are: 1-Compressor wheel. 2-Compressor housing. 3-Thrust bearing. 4-Lubrication inlet port. 5-Turbine housing. 6-Turbine wheel. 7-Air inlet. 8-Exhaust outlet. 9-Sleeve. 10-Shaft journal bearings. 11-Sleeve. 12-Exhaust inlet.
The turbocharger bearings are pressure-lubricated by engine oil. The oil enters the top of the center section and is directed through passages to lubricate the thrust bearing, sleeves and the journal bearings of the turbocharger. Oil leaves the turbocharger through a port in the bottom of the center section and is returned to the engine sump.
Altitude Operation
Maximum turbocharger speed is determined by the rack setting, the high idle speed setting and the altitude at which the engine is operated.
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If the high idle speed or the rack setting is greater than specified for the altitude at which the engine is operated, serious damage to engine or turbocharger parts can result. |
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The fuel pump rack has been set by qualified personnel for a particular engine application. The governor housing and turbocharger are sealed to prevent unqualified personnel from adjusting the rack and the high idle speed.
Turbocharger Removal And Installation
See the topic TURBOCHARGER REMOVAL in the AIR INDUCTION AND EXHAUST SYSTEM Group 270.4.
Turbocharger Disassembly And Assembly
- FT-621 Holding and Positioning Fixture.FT-622 Cartridge Fixture.FT-175 Ring Expander Sleeve.FT-745 Internal Pliers.
NOTE: Mark position of bands (1) and (10), center housing (3) and end housings so alignment at assembly will be the same.
1, 10 Lubricate face and threads of clamp bands clamp nuts. The FT-621 Holding and Positioning Fixture is convenient for disassembly and assembly.
This illustrates the use of the FT-622 Cartridge Fixture and the turbine housing held in position with the FT-621 Holding and Positioning Fixture.
3, 8, 9 Remove nut (9) with a 3/4 in. Universal Socket when the assembly is sitting in the FT-622 Cartridge Fixture. The compressor wheel (8) is a slip fit and can be easily removed.
At assembly, use similar setup of fabricated tools shown for disassembly and proceed as follows:
a. Install shims and compressor wheel (8) on shaft. Lubricate and install nut (9) to specified torque.
b. Check clearance between compressor wheel and housing (3). Adjust shim thickness to give .018-.022 in. (0,460-0,550 mm) clearance between housing and compressor wheel.
c. Check shaft end clearance .004-.006 in. (0,10-0,15 mm).
Insert (6) is removed by prying with two screw-drivers, on the ledge on the insert.
Remove bearing retainer snap rings (7) with FT-745 Internal Pliers. Other snap rings are removed with similar pliers.
NOTE: Use extreme care in snap ring removal and installation to avoid damaging the housing bearing bore. Install rounded side of snap rings facing bearings (4).
This illustrates the use of FT-745 Internal Pliers to remove or install bearing retainer snap rings.
Install rings (2) in shaft and rings (5) sleeve grooves with FT-175 Ring Expander Sleeve. Position ring gaps 180° apart.
Install bearing (4) with internal grooves toward compressor end.