SECTION 3 - CHASSIS & TURNTABLE
3-28
– JLG Lift –
3121290
VALVE PLATE
Valve plate condition is critical to motor efficiency. Inspect
valve plate surfaces for excessive wear, grooves, or scratches.
Replace or resurface grooved or scratched valve plates. Mea-
sure valve plate thickness and replace if worn beyond mini-
mum specification.
Valve plate can be resurfaced if finished thickness is not below
minimum specification shown in drawing.
SWASHPLATE AND JOURNAL BEARINGS
Inspect running face, servo ball-joint, and swashplate journal
surfaces for damage or excessive wear.
Some material transfer may appear on these surfaces and is
acceptable providing surface condition meets specifications
shown.
Measure swashplate thickness from journals to running face.
Replace swashplate if damaged or worn beyond minimum
specification.
Inspect journal bearings for damage or excessive wear.
Replace journal bearings if scratched, warped, or excessively
worn. Polymer wear layer must be smooth and intact.
SHAFT BEARINGS
Inspect bearings for excessive wear or contamination. Rotate
bearings while feeling for uneven movement. Bearings should
spin smoothly and freely. Replace bearings that appear worn
or do not rotate smoothly.
SHAFT
Inspect motor shaft. Look for damage or excessive wear on
output and block splines. Inspect bearing surfaces and sealing
surface. Replace shafts with damaged or excessively worn
splines, bearing surfaces, or sealing surfaces.
SERVO PISTON AND MINIMUM ANGLE STOP
Inspect minimum angle stop, servo piston head, and servo pis-
ton ball-socket for damage or excessive wear. Replace as needed.
LOOP FLUSHING SPOOL
Inspect loop flushing spool. Check for cracks or damage.
Replace as needed.
3.83 mm [0.151 in] min.
0.025 mm
[0.001 in]
0.0076 mm
[0.00030 in]
convex max
LV
25.8 mm
[1.015 in]
24.6 mm
[0.969 in]
KV
Thickness equality
side to side:
0.05 mm [0.002 in]
0.0025 mm
[0.0001 in]
Summary of Contents for 450A II Series
Page 46: ...SECTION 3 CHASSIS TURNTABLE 3 6 JLG Lift 3121290 Figure 3 4 Drive Hub 4WD Front Only ...
Page 79: ...SECTION 3 CHASSIS TURNTABLE 3121290 JLG Lift 3 39 Figure 3 32 Swing Bearing Drive ...
Page 101: ...SECTION 3 CHASSIS TURNTABLE 3121290 JLG Lift 3 61 Figure 3 42 Auxiliary Pump ...
Page 113: ...SECTION 3 CHASSIS TURNTABLE 3121290 JLG Lift 3 73 Figure 3 53 EMR2 Fault Codes Sheet 1 of 5 ...
Page 114: ...SECTION 3 CHASSIS TURNTABLE 3 74 JLG Lift 3121290 Figure 3 54 EMR2 Fault Codes Sheet 2 of 5 ...
Page 115: ...SECTION 3 CHASSIS TURNTABLE 3121290 JLG Lift 3 75 Figure 3 55 EMR2 Fault Codes Sheet 3 of 5 ...
Page 116: ...SECTION 3 CHASSIS TURNTABLE 3 76 JLG Lift 3121290 Figure 3 56 EMR2 Fault Codes Sheet 4 of 5 ...
Page 117: ...SECTION 3 CHASSIS TURNTABLE 3121290 JLG Lift 3 77 Figure 3 57 EMR2 Fault Codes Sheet 5 of 5 ...
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Page 173: ...SECTION 3 CHASSIS TURNTABLE 3121290 JLG Lift 3 133 Sensor Transducer Type ...
Page 177: ...SECTION 3 CHASSIS TURNTABLE 3121290 JLG Lift 3 137 Sensor Transducer Type ...
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Page 217: ...SECTION 4 BOOM PLATFORM 3121290 JLG Lift 4 5 Figure 4 2 Boom Limit Switches ...
Page 310: ...SECTION 5 HYDRAULICS 5 70 JLG Lift 3121290 NOTES ...
Page 312: ...SECTION 6 JLG CONTROL SYSTEM 6 2 JLG Lift 3121290 Figure 6 2 Controller Block Diagram 0 ...
Page 370: ...SECTION 6 JLG CONTROL SYSTEM 6 60 JLG Lift 3121290 NOTES ...
Page 394: ...SECTION 7 BASIC ELECTRICAL INFORMATION SCHEMATICS 7 24 JLG Lift 3121290 NOTES ...
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