Flush the oil passages in the center housing from the drain end using dry cleaning solvent PD-680, Type II,
Steam dean the parts to remove any remaining carbon or grease, and blow dry the parts using filtered,
moisture free compressed air.
Place the cleaned parts in compartmented trays, and cover them to avoid contamination.
Inspect. Inspect all components and replace defective parts as noted. Repair or replace other defective parts in
accordance with step d or e, below.
Inspect the V-band (2, Figure 9-70) for distortion and cracks, and the bolt for damaged threads. Replace
the V-band if it is cracked or the bolt threads are stripped.
Check all threaded fasteners and holes for damaged or stripped threads. Replace stripped capscrews.
Repair stripped holes in accordance with paragraph 2-12. Check the prevailing torque of the locknuts in
accordance with Table 1-3. Replace locknuts that are below the minimum prevailing torque.
Inspect the clamps (6) for bending, distortion, and cracks. Replace defective damps.
Check the compressor housing contour areas for scoring, grooving, and signs of impeller rub, and rust (A,
Figure 9-71). Check the mounting flanges (B, Figure 9-71) for cracks.
Check the turbine housing contour area for scoring, grooving, burning, and signs of turbine rub (A, Figure
9-72). Check the mounting flanges (B, Figure 9-72) for cracks or rust.
Check the center housing (18, Figure 9-70) for cracks, burning, and pitting, and check the bearing bores for
wear and out-of-round using a telescoping gage and outside micrometer.
If the turbocharger is being overhauled, replace the backplate (17) regardless of physical
Check the back-plate (17) for scoring and wear in the area of the thrust collar and impeller.
Check the shroud (12) for scoring, grooving, and turbine rub.
Inspect the compressor housing (3), turbine housing (7), back-plate (1 7), center housing (18), and shroud
(12).Replace parts that are cracked or porous.
Check the impeller for cracks, nicks, scoring, and rub damage (Figure 9-73). Replace the impeller if it is
Inspect the impeller (9, Figure 9-70). Replace the impeller if it is cracked.
Turbine wheel and shaft. (See Figure 9-74.)
Check the turbine wheel for cracks, nicks, scoring, and rub damage. Replace the turbine wheel and
shaft if it is cracked.
Check for cracks, scoring, and porosity in the weld area.
Check the shaft diameter in the bearing area for wear, scoring, and out-of-round.
Check the shaft seal ring groove for wear, using a new seal ring and a feeler gage. Maximum
clearance shall be 0.008 inch (0.20 mm).
Support the shaft in V-blocks at the bearing journal areas and check the shaft for runout. Replace the
turbine wheel and shaft if the runout exceeds 0.0005 inch (0.013 mm).
If the turbocharger is being overhauled, replace the thrust spacer (13, Figure 970), thrust
collar (19), thrust bearing (20), bearings (22), and washers (23) regardless of physical
Check the thrust spacer (13, Figure 9-70) for scoring or grooving. Check the ring groove clearance using a
new seal ring (14) and a feeler gage. Maximum clearance shall be 0.009 inch (0.23 mm).
Check the thrust collar (19) for scoring or grooving. Scoring shall not exceed 0.003 inch (0.08 mm) in