Inspection Before Disassembly; Disassembly - Komatsu 4D98 Series Shop Manual

8. Turbocharger (for 4TNE706T)
(2)
Inspection before disassembly
(2-l)
(2.2)
.
.
Inspect the turbine wheel and compressor impeller for any undesirable contact and the rotor
for smooth rotation.
(3)
Disassembly
The mounting angles of the turbine housing, bearing housing and compressor housing are
determined according to its mounting state on the engine. Put match marks before starting
disassembly.
Measure the rotor play as described in section 8.3 (2.2).
Rotor axial play
Wear limit : 0.09 mm
Rotor radial play Wear limit : 0.17 mm
Note) The number after each part is the one described in the structural drawing in 8.1 (2).
(3.1) Compressor housing removal
@ Remove flanged hexagon bolt 8 and compressor side keep plate 10.
@ Remove compressor housing 7.
Note- 1) Liquid gasket is applied on the surface of compressor housing 7 where bearing
housing 15 is mounted.
Note-2) When disassembling compressor housing 7, carefully operate so as not to dam-
age the compressor impeller.
(3.2) Compressor impeller removal
@ Set a box spanner (10 mm) on the turbine side end of the turbine shaft, and remove shaft
end clamp 18.
Note)
Pay attention to the loosening direction since the shaft end nut has lee-handed
screw.
@ Remove compressor impeller 18.
(3.3) Turbine housing removal
@ Remove hexagon nut 12 and turbine side keep plate 13.
@ Remove turbine housing 11.
(3.4) Turbine shaft extraction
@ Hold heat insulating plate 20 lightly with a hand, and extract turbine shaft 1.
Note) If the turbine shaft is hard to be extracted, tap the compressor side end of the
shaft lightly with a wooden hammer.
@ Remove heat insulating plate 20.
(3.5) Seal plate removal
@ Use the Torx driver and loosen M3 Torx T-type machine screw 17 for seal plate mounting.
@ Remove seal plate 4.
Note) Liquid gasket has been applied to the seal plate and bearing housing mounting
surface.
@ Remove oil thrower 2 from the seal plate.
8-9