TM 5-6115-400-35
(b) Move impeller to extreme UP
position.
Note and record the
indication.
(c) Move impeller to extreme DOWN
position.
Note and record
indication. The difference between
indications is total end play.
(d) Permissible end play is .003 inch to
.008 inch. End play more than .008
inch indicates that the thrust ring,
thrust bearing, or bearing surface of
the center housing thrust plate
assembly is worn. If end play is
less than .003 inch, carbon buildup
behind the turbine impeller is
indicated. In either case, the unit
must be disassembled and the
condition corrected.
(6) Remove the turbine housing. (Refer to
paragraph d).
(7) Inspect
the
compressor
housing,
compressor impeller, turbine impeller, and
turbine housing for dirt accumulations that
impair turbocharger performance. Large,
unevenly distributed accumulations of dirt
on the impellers will disturb the precision
balance of the rotating parts assembly.
Refer to paragraph e for cleaning
procedure.
(8) Make a thorough inspection of the
Figure 30. Checking turbine shaft radial movement.
compressor and turbine impellers. Wear
on the outer and small diameters of the
compressor impeller blades indicates
(h) Radial movement in excess of .008
extreme impeller shaft bearing and thrust
inch is an indication that the shaft or
bearing wear on the turbine side of the
bearing is worn or that the bearing
unit. Wear appearing on turbine impeller
bore in the housing is worn. The
blades indicates undue wear of impeller
unit must be disassembled and
shaft bearings. Broken or bent blades are
reconditioned.
an indication that large pieces of foreign
Note.
material
have
gone
through
the
Shaft radial movement can be
compressor or turbine.
A damaged
checked without removing the
blade(s) can throw the rotating assembly
turbocharger from the engine.
out of balance and shorten the life of the
Remove oil drain line from the center
turbocharger. Do not attempt to repair a
housing and follow the same
damaged
impeller
because
total
procedure detailed in steps (b)
destruction of the turbocharger may
through (h) above.
result.
(5) Check shaft end play as follows:
(a) Position dial indicator so contact
point is resting on the impeller shaft
end.
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