Section 6.5
Turbocharger (Diesel)
The turbocharger is designed to increase the overall power and efficiency of the engine. Power to drive the turbocharger is extracted from the energy in the engine exhaust gas.
A turbocharger can be broken down into three basic pieces; a compressor cover, a center housing rotating assembly (CHRA), and a turbine housing.
The compressor cover provides a hose connection for the compressor inlet, and a V-band connection for the compressor outlet. The compressor cover is secured to the compressor side of the CHRA, and encloses the compressor wheel.
The CHRA contains a turbine wheel and shaft assembly, piston ring(s), thrust spacer, compressor wheel, and wheel retaining nut. This rotating assembly is supported on two pressure-lubricated bearings that are retained in the center housing by snap rings. Internal oil passages are drilled in the center housing to provide lubrication to the turbine wheel shaft bearings, thrust washer, thrust collar, and thrust spacer.
The turbine housing is a heat-resistant steel alloy casting that encloses the turbine wheel and provides a flanged engine exhaust gas inlet and an axially located turbocharger exhaust gas outlet. The turbine housing is secured to the turbine end of the center housing.
The Garrett (formerly Airesearch) family of turbochargers look similar. The model TV51 turbocharger is used on all Series 60 diesel engines through the 1989 models. The TV45 turbocharger is used on 1991 and later 11.1 liter displacement diesel engines. See Figure "TV45, TV51 Turbocharger Assembly" .
Figure 1. TV45, TV51 Turbocharger Assembly
The TMF turbocharger is used on 1990 and later 12.7 liter displacement engines. See Figure "TMF Turbocharger Assembly" .
Figure 2. TMF Turbocharger Assembly
The turbocharger is mounted on the exhaust outlet flange of the engine exhaust manifold. After the engine is started, the exhaust gases flow from the engine and through the turbine housing causing the turbine wheel and shaft to rotate. See Figure "Schematic Air Flow Diagram" .
Figure 3. Schematic Air Flow Diagram
The gases are discharged into the exhaust system after passing through the turbine housing.
The compressor wheel, in the compressor housing, is mounted on the opposite end of the turbine wheel shaft and rotates with the turbine wheel. The compressor wheel draws in clean air, compresses it, and delivers high pressure air through the intake manifold to the engine cylinders.
Oil for lubricating the turbocharger is supplied under pressure through an external oil line extending from the oil filter adaptor to the top of the center housing. See Figure "Turbocharger Oil Lines" .
1. Elbow, Oil Drain Tube |
10. Connector, Oil Supply Tube |
2. Bolt, Mounting Bracket |
11. Tube Assembly, Turbo Oil Supply |
3. Bolt, Oil Drain Tube Clip |
12. Clip, Oil Supply Tube |
4. Tube, Turbo Oil Drain |
13. Bolt, Oil Supply Tube Clip |
5. Bolt, Oil Drain Tube Mounting |
14. Connector, Oil Supply Tube (to turbocharger) |
6. Gasket, Turbo Oil Drain Tube |
15. Gasket, Turbo Exhaust Inlet |
7. Nut, Turbo Mounting |
16. Clip, Oil Drain Tube |
8. Washer, Turbo Mounting |
17. Bracket, Oil Drain Tube Clip Mounting |
9. Turbocharger Assembly |
18. Nut, Oil Drain Tube Clip |
Figure 4. Turbocharger Oil Lines
From the oil inlet in the center housing, the oil flows through the drilled oil passages in the housing to the shaft bearings, thrust ring, thrust bearing, and backplate or thrust plate. See Figure "Turbocharger Oil Flow Diagram" .
1. Compressor Wheel |
6. Shaft |
2. Thrust Bearing |
7. Turbine Wheel |
3. Backplate |
8. Shaft Bearings |
4. Oil Inlet |
9. Oil Outlet |
5. Center Housing |
|
Figure 5. Turbocharger Oil Flow Diagram
The oil returns by gravity to the engine oil pan through an external oil line extending from the bottom of the turbocharger center housing to the cylinder block. See Figure "Turbocharger Oil Lines" .
If the turbocharger is water-cooled, the coolant supply line is connected to the bottom of the turbine housing, and the coolant return/bypass line is connected to the top. Coolant from the fresh water pump flows through the supply line into the turbine housing, passes into the thermostat housing then flows back to the heat exchanger, thus lowering its temperature.
For Series 60 engines with Exhaust Gas Recirculation (EGR) systems: The variable nozzle turbine (VNT) turbocharger uses a high pressure pneumatic actuator to regulate and control the Exhaust Gas Recirculation (EGR) system. There is no wastegate with this system. The VNT actuator is mounted on a bracket attached to the turbocharger and receives air pressure from the engine-mounted Variable Pressure Output Device (VPOD). The VNT actuator connects via a rod end to a pin joint of the turbine external arm. Rotation of the external arm simultaneously rotates several pivoting nozzle vanes positioned inside the turbine housing at the outer periphery of the turbine wheel, adjusting turbocharger speed and boost in accordance with the DDEC engine management control. A second actuator is the EGR valve actuator that controls the variable position of the EGR valve. The EGR valve outlet is connected to the EGR cooler and recirculates a fraction of the engine exhaust gases to the intake manifold for purposes of engine emission control. The Delta-P (Differential Pressure) sensor uses the differential pressure created by using a fixed orifice and pressure ports on either side of the fixed orifice to determine the actual EGR flow rate. The Delta-P sensor is the feedback loop to the ECM so the ECM can increase or decrease EGR flow via the VPODs, and determine if the EGR system is functioning properly. The EGR temperature sensor is used in conjunction with the Delta-P sensor to determine flow rate and the warn operator of EGR system malfunctions.
Section 6.5.1
Repair or Replacement of Turbocharger
To determine if repair is possible or replacement of the turbocharger is necessary perform the following procedure. See Figure "Flowchart for Repair or Replacement of Turbocharger" .
Note: VNT Turbochargers can only be repaired at a authorized service facility. Service is limited to replacement only.
Figure 6. Flowchart for Repair or Replacement of Turbocharger
Section 6.5.2
Removal and Cleaning of Turbocharger
Cleaning the turbocharger is not necessary before removal.
PERSONAL INJURY |
To avoid injury from hot surfaces, wear protective gloves, or allow engine to cool before removing any component. |
PERSONAL INJURY |
To avoid injury from contact with rotating parts when an engine is operating with the air inlet piping removed, install an air inlet screen shield over the turbocharger air inlet. The shield prevents contact with rotating parts. |
Many Series 60 engines use turbochargers with ceramic turbine (exhaust) wheels. To avoid ceramic wheel damage, care must be taken to remove debris after servicing the air intake and exhaust systems on these engines.
NOTICE: |
If the ceramic wheel becomes damaged or bursts, Detroit Diesel recommends replacing the exhaust system muffler if positioned in such a way that debris will fall back into the turbine housing. This precaution will prevent damage to the turbocharger at engine start-up. |
Prior to removal, visually check for:
- Missing or loose nuts and bolts.
- Loose or damaged intake and exhaust ducting.
- Damaged oil supply and drain lines.
- Cracked or deteriorating turbocharger housings.
- External oil leakage or coolant leakage, if water-cooled.
- Replace damaged parts with new parts.
To remove the turbocharger, perform the following:
NOTICE: |
Do not attempt to remove carbon or dirt buildup on the compressor or turbine wheels without removing the turbocharger from the engine. If chunks of carbon are left on the blades, an unbalanced condition will exist and subsequent failure of the bearings will result if the turbocharger is operated. However, it is not necessary to disassemble the turbocharger to remove dirt or dust buildup. |
- Disconnect and remove the CAC ducting at the compressor housing.
- Disconnect and remove the air inlet hose attached to the compressor housing. Refer to "6.8.2 Removal and Cleaning of Charge Air Cooler" .
- Disconnect the exhaust outlet pipe from the turbine housing of the turbocharger. For proper operation, the turbocharger rotating assembly must turn freely. Whenever the exhaust ducting is removed, spin the turbine wheel by hand.
- Remove the inlet oil line from the top of the center housing.
- Remove the oil drain line from the bottom of the center housing.
- If turbocharger is water-cooled, drain coolant into a suitable container until engine coolant level is below the turbine inlet flange. Remove coolant inlet and outlet hoses from turbocharger.
- Attach a chain hoist and a suitable lifting sling to the turbocharger assembly.
- Remove the nuts securing the turbocharger assembly to the exhaust manifold. Then, lift the turbocharger assembly away from the engine and place it on a bench.
- Cover the end of the oil drain line, the oil outlet line, coolant inlet and outlet hoses (if water-cooled turbocharger), the air inlet and the exhaust outlet openings on the engine and turbocharger, to prevent the entry of foreign material.
PERSONAL INJURY
To avoid injury from improper use of chemicals, follow the chemical manufacturer's usage, handling, and disposal instructions. Observe all manufacturer's cautions.
- Clean the exterior of the turbocharger with a non-caustic cleaning solvent before disassembly.
Section 6.5.3
Disassembly of Turbocharger
VNT turbochargers are not repairable. Repair work on the VNT is limited to its replacement.
Prior to disassembly, the exterior of the turbocharger must be cleaned. Refer to "6.5.2 Removal and Cleaning of Turbocharger" , step 10 .
Disassemble the turbocharger as follows:
- Mark the related positions of the compressor housing, center housing and turbine housing with a punch or scribe to assure reassembly in the same relative position.
NOTICE:
Exercise care when removing the compressor housing and turbine housing to prevent damage to the compressor and turbine wheels.
- Loosen the V-band coupling securing the compressor housing to the backplate assembly and remove the compressor housing and V-band.
- Perform the following steps to disassemble the TV45 or TV51 turbocharger: See Figure
"Typical Turbocharger"
.
- Loosen the V-band coupling securing the turbine housing to the center housing.
- Remove the turbine housing from the center housing.
1. Compressor Housing
3. Turbine Housing
2. Compressor Housing and Rotating Assembly
4. V-band Couplings
Figure 7. Typical Turbocharger
- Perform the following steps to disassemble the TMF turbocharger. See Figure
"Series TMF Turbocharger"
.
- Remove the four bolts securing the turbine housing to the center housing. If they are 3/8 in. hex-head bolts, discard them and replace with new 5/8 in. hex-head bolts.
- Remove the turbine housing from the center housing.
1. Compressor Housing
4. Bolt
2. V-band Coupling
5. Center Housing
3. Compressor Housing and Rotating Assembly
6. Turbine Housing
Figure 8. Series TMF Turbocharger
Section 6.5.3.1
Inspection of Turbocharger
Inspect the disassembled turbocharger, discarding any damaged parts, in the following manner:
- Visually check for nicked, crossed or stripped threads.
- Visually check the turbine wheel shroud and turbine wheel for signs of rubbing.
- Visually check the compressor wheel for signs of rubbing or damage from foreign material. The wheel must be free of dirt and other foreign material.
- Check the bearing axial end play:
- Clamp the center housing assembly in a bench vise equipped with soft jaws. See Figure "Checking Bearing Axial End Play" .
- Fasten the dial indicator and magnetic clamp, part of magnetic base dial indicator set (J–7872) to the center housing so that the indicator tip rests on the end of the rotating shaft on the compressor side. See Figure "Checking Bearing Axial End Play" .
- Move the shaft axially back and forth by hand. The total indicator reading (thrust float) should be 0.004-0.009 in. (0.1016-0.2286 mm) for TMF turbochargers. The total indicator reading should be 0.003 to 0.010 in. (0.0762-0.254 mm) for TV45 and TV51 turbochargers. If the total dial indicator readings do not fall within the specified limits, replace the rotating assembly.
Figure 9. Checking Bearing Axial End Play
- Check the shaft radial movement as follows:
- Install the turbo shaft checker (J–39164) to the oil drain opening of the center section. The special curved end of the tool must contact the wheel shaft through the oil outlet port and an internal opening in the center section casting. See Figure "Checking Shaft Radial Movement" .
- Install a dial indicator. See Figure "Checking Shaft Radial Movement" .
- Place the swivel adaptor, part of magnetic base dial indicator set, against the scribed line of the turbo shaft checker (J–39164) .
- Grasp each end of the rotating assembly and, applying equal pressure at each end, move the rotating shaft first toward and then away from the dial indicator, creating a transverse movement in the shaft. The total indicator reading (radial movement) should be 0.005-0.007 in. (0.127-0.178 mm) for TMF turbochargers. The total indicator reading should be 0.005-0.0065 in. (0.127-0.165 mm) for TV45 and TV51 turbochargers. If the total indicator readings do not fall within the specified limits, replace the rotating assembly.
Figure 10. Checking Shaft Radial Movement
Section 6.5.3.2
Checking Wastegate Calibration
Check the wastegate calibration as follows:
Note: Turbochargers used on some engines do not have wastegates.
- Remove hose from wastegate actuator.
- Using DDC tool set, TLZ00100, set up an indicator at the end of the wastegate actuator adjusting rod to measure actuator rod travel. The indicator should have a minimum travel of 2.54 mm (0.100 in.).
- Connect regulator and pressure gage setup to wastegate actuator. See Figure
"Checking Wastegate Calibration"
.
Figure 11. Checking Wastegate Calibration
- Apply specified calibration pressure as listed in Table
"Wastegate Calibrations"
, to the wastegate actuator.
Manufacturer
Model
Rating
Can Pressure
Rod Travel
Garrett®
11.1L
330–350 Hp
182.71-189.61 kPa (26.5–27.5 psi)
1.016 mm (0.040 in.)
Garrett®
12.7L
330–500 Hp
210.29-217.19 kPa (30.5–31.5 psi)
1.016 mm (0.040 in.)
Garrett®
14.0L
550–575 Hp
210.29-217.19 kPa (30.5–31.5 psi)
1.016 mm (0.040 in.)
BorgWagner Turbo Systems®
12.7
330–430 Hp
234.22-234.63 kPa (33.97–34.03 psi)
1.45-2.26 mm (0.057–0.089 in.)
Garrett® is a registered trademark of Honeywell.
BorgWagner Turbo Systems® is a registered trademark of BorgWagner Corportation. - Close air supply shutoff valve. The pressure should hold at the specified pressure. If not, check air hose and fitting connections for leaks. If none are found, replace wastegate actuator. Refer to "6.5.4 Removal of Wastegate Actuator" .
- Open vent to relieve pressure. Check gage for zero pressure reading. Adjust regulator to zero pressure and close vent valve.
- Adjust dial indicator so it just contacts the actuator rod end and adjust to zero reading.
- Open air supply shutoff valve and slowly adjust regulator until dial indicator reads 1.016 mm (0.040 in.) for Garrett® systems and 1.45-2.26 mm (0.057–0.089 in.) for BorgWagner Turbo Systems®. Switch pressure on and off, opening and closing supply air and vent valves, to ensure dial indicator travel is from 0.00–1.016 mm (0.00–0.040 in.) for Garrett® systems or 0.00–2.26 mm (0.00–0.089 in.) for BorgWagner Turbo Systems®; and that the pressure reading is consistent.
- For currently calibrated wastegate actuator, a pressure within ± 3.4 kPa (0.50 psi) of the value listed in Table "Wastegate Calibrations" , will be required to obtain precisely the correct amount of actuator rod travel. If the pressure required is outside this range, wastegate adjustment is necessary. Refer to "6.5.5.1 Setting the Wastegate" .
Section 6.5.4
Removal of Wastegate Actuator
Remove the wastegate actuator as follows:
- Remove actuator hose from top side of actuator can. See Figure "Checking Wastegate Calibration" . With the pressure gage setup, apply enough pressure to the actuator can until the rod begins to move. Refer to "6.5.5.1 Setting the Wastegate" .
- Remove the retaining clip that holds the actuator rod end on the worm pin. Lift rod off the wastegate lever pin.
NOTICE:
Never remove the rod end from the wastegate lever pin without applying pressure to the top side actuator port, or damage to the actuator diaphragm may result.
- Remove the locknuts that secure the actuator can to the base of the actuator bracket and remove the can from the turbocharger assembly.
Section 6.5.5
Installation of Wastegate Actuator
Further adjustment of the actuator will be necessary to achieve the correct pressure setting, listed in Table "Wastegate Calibrations" .
Install the wastegate actuator as follows:
- Install actuator can on bracket; tighten locknuts.
- Using pressure gage setup, apply enough pressure to the new service actuator can until the rod begins to move.
- Adjust actuator rod end by turning either clockwise or counterclockwise on rod so that the rod end hole lines up with the wastegate lever arm. While wastegate is held shut, slip rod over pin.
- Before installing retaining clip, the rod end will need to be adjusted to the correct setting. Refer to "6.5.5.1 Setting the Wastegate" .
Section 6.5.5.1
Setting the Wastegate
Before following this procedure, check the actuator set pressure to see if adjustment is needed. Refer to "6.5.5.1 Setting the Wastegate" .
Set pressure adjustment as follows:
- Loosen the jam nut that secures the rod end on the actuator rod. If locking collar is present on the actuator rod, remove and discard collar. See Figure
"Wastegate Adjustment"
.
1. Wastegate Actuator Assembly
4. Adjusting Rod End
2. Locking Collar
5. Retainer Clip
3. Jam Nut
6. Wastegate Lever and Pin Assembly
Figure 12. Wastegate Adjustment
- Remove the retaining clip that holds the actuator rod end on the wastegate lever arm pin.
- Using pressure gage setup, apply enough pressure to the top side actuator can port until the rod begins to move, lifting the wastegate valve off its seal. See Figure "Wastegate Adjustment" .
- Slip rod end off the wastegate lever arm pin.
- Adjust rod as needed:
- To INCREASE pressure setting at 1.0 mm (0.04 in), turn rod end CLOCKWISE.
- To DECREASE pressure setting at 1.0 mm (0.04 in), turn rod end COUNTERCLOCKWISE.
- With pressure still applied to actuator, replace rod end on wastegate lever arm.
- Check actuator set pressure again. Refer to "6.5.5.1 Setting the Wastegate" .
- If actuator is still out of adjustment, repeat this procedure.
- If actuator is within specified set pressure, install retaining clip on wastegate lever arm pin.
- Tighten jam nut to secure rod end.
Section 6.5.6
Assembly of Turbocharger
Use the following procedure to assemble the turbocharger:
NOTICE: |
As the parts are assembled, cover the openings to prevent entry of dirt or other foreign material, which may cause component damage. |
- Cover all openings.
- Position the turbine housing as marked at disassembly against the center housing and secure it in place.
- If a TMF turbocharger is to be assembled, proceed to step 5
.
NOTICE:
Failure to properly orient the Tee-bolt end of the clamp can result in an exhaust leak, turbine wheel damage or both.
- To assemble the TV45 and TV51 turbochargers, position the V-band coupling between the turbine housing and center housing so that the Tee-bolt end does not interfere with the turbine housing. Then tighten the V-band coupling nut, as follows:
- Lubricate the toggle bolt threads with a high temperature anti-seize compound.
- Tighten the nut on the V-band toggle bolt to approximately 18 N·m (160 lb· in.) torque.
- Loosen the V-band coupling nut to approximately 6 N·m (50 lb· in.) torque, then torque the nut to 12-15 N·m (106-133 lb· in.).
Note: Do not pull a misaligned turbine housing into alignment with the V-band coupling. The parts must be aligned and seated first.
- Position the compressor housing as marked at disassembly against the backplate assembly and secure it in place with the V-band coupling.
- Lightly lubricate the threads of the toggle bolt with engine oil and tighten the nut to 12-15 N·m (106-133 lb· in.) torque. This completes the assembly of TV45 and TV51 turbochargers.
NOTICE:
The 5/8 in. hex-head turbine housing bolts replaced 3/8 in. hex-head bolts. The 5/8 in. hex-head bolts are required to ensure sufficient clamp load.
- Secure the TMF turbine housing with four 5/8 in. hex-head bolts.
- Tighten the bolts to 34 N·m (301 lb· in.) torque.
Section 6.5.7
Installation of Turbocharger
To install the turbocharger:
- Attach a chain hoist and a suitable lifting sling to the turbocharger assembly.
- Remove any covers that were placed over the openings of the air inlet and exhaust outlet openings on the engine and turbocharger when the turbocharger was removed.
- Remove any covers on the oil inlet and drain lines, and the oil inlet and drain openings on the turbocharger.
- Place the turbocharger assembly into position on the exhaust manifold. Use a new gasket between the exhaust manifold and the turbine housing flange.
- Secure the turbocharger to the exhaust flange. Tighten the nuts just enough to hold the turbocharger in place.
- Slide the charge air cooler air inlet tube hose over the compressor housing outlet opening and secure it in place with the hose clamps.
PERSONAL INJURY
To avoid injury from the sudden release of a high-pressure hose connection, wear a face shield or goggles.
Note: Do not use any type of lubricant on the inside of any air inlet hose or on the hose contact surfaces of the turbocharger compressor housing, CAC ducting or the intake manifold.
- Tighten the turbocharger to exhaust manifold locknuts to 58-73 N·m (43-54 lb·ft) torque.
- Install the oil drain line, using a new gasket, between the opening in the bottom side of the turbocharger center housing and the drain hose that runs to the cylinder block. Tighten the bolts to 30-38 N·m (22-28 lb·ft) torque.
- If turbocharger is water cooled, install the coolant supply and return hoses.
- Refer to "12.3 Running" for verification of proper turbocharger installation.
- Place base gasket over studs on exhaust manifold.
- Place turbocharger over studs.
- Install four M10 nuts and washers and torque to 49 N·m (36 lb·ft).
- Connect air line to VNT actuator and torque to 20 N·m (15 lb·ft).
- Install turbocharger compressor outlet temperature sensor.
- Install turbocharger speed sensor.Refer to "2.22 Turbo Speed Sensor (TSS)" . Connect air line from variable pressure output device (VPOD) to actuator on VNT.
For Series 60 engines with Exhaust Gas Recirculation (EGR) systems install the VNT turbocharger as follows:
Series 60 Service Manual - 6SE483 |
Generated on 10-13-2008 |