Dodge RAM 1500 1998 Owner's Manual page 1540

DR
TURBOCHARGER (Continued)
(9) Remove the turbocharger and gasket from the
exhaust manifold.
(10) If the turbocharger is not to be installed
immediately, cover the opening to prevent material
from entering into the manifold.
(11) If replacing the turbocharger, transfer the tur-
bocharger oil supply fitting to the new assembly.
Tighten fitting to 36 N·m (27 ft. lbs.).
(12) Clean and inspect the sealing surface.
CAUTION: The turbocharger is only serviced as an
assembly. Do not attempt to repair the turbocharger
as turbocharger and/or engine damage can result.
CLEANING
WARNING: To prevent damage or personal injury,
do not use a combustable cleaner to clean the tur-
bocharger.
Clean the turbocharger and exhaust manifold
mounting surfaces with a suitable scraper.
INSPECTION
Visually inspect the turbocharger and exhaust
manifold gasket surfaces. Replace stripped or eroded
mounting studs.
(1) Visually inspect the turbocharger for cracks.
The following cracks are NOT acceptable:
• Cracks in the turbine and compressor housing
that go completely through.
• Cracks in the mounting flange that are longer
than 15 mm (0.6 in.).
• Cracks in the mounting flange that intersect
bolt through-holes.
• Two (2) Cracks in the mounting flange that are
closer than 6.4 mm (0.25 in.) together.
(2) Visually inspect the impeller and compressor
wheel fins for nicks, cracks, or chips. Note: Some
impellers may have a factory placed paint mark
which, after normal operation, appears to be a crack.
Remove this mark with a suitable solvent to verify
that it is not a crack.
(3) Visually inspect the turbocharger compressor
housing for an impeller rubbing condition (Fig. 20).
Replace the turbocharger if the condition exists.
(4) Measure the turbocharger axial end play:
(a) Install a dial indicator as shown in (Fig. 21).
Zero the indicator at one end of travel.
(b) Move the impeller shaft fore and aft and
record the measurement. Allowable end play is
0.026 mm (0.0001 in.) MIN. and 0.127 mm (0.005
in.) MAX. If the recorded measurement falls out-
side these parameters, replace the turbocharger
assembly.
(5) Measure the turbocharger bearing radial clear-
ance:
(a) Insert a narrow blade or wire style feeler
gauge between the compressor wheel and the hous-
ing (Fig. 22).
(b) Gently push the compressor wheel toward
the housing and record the clearance.
(c) With the feeler gauge in the same location,
gently push the compressor wheel away from the
housing and again record the clearance.
(d) Subtract the smaller clearance from the
larger clearance. This is the radial bearing clear-
ance.
(e) Allowable radial bearing clearance is 0.33
mm (0.013 in.) MIN. and 0.50 mm (0.020 in.) MAX.
If the recorded measurement falls outside these
specifications, replace the turbocharger assembly.
Fig. 20 Inspect Compressor Housing for Impeller
Rubbing Condition
Fig. 21 Measure Turbocharger Axial End Play
INSTALLATION
(1) Install the turbocharger. Apply anti-seize to the
studs and then tighten the turbocharger mounting
nuts to 43 N·m (32 ft. lbs.) torque.
EXHAUST SYSTEM 11 - 15