Usage:
Problem:
Misalignment between the engine and the hydrostatic pump may be caused by missing dowel pins from the flywheel housing. The dowel pins are necessary to locate the flywheel housing correctly onto the engine block. When the dowel pins are not installed, there will be a misalignment between the engine and the hydrostatic pump. As a result of this misalignment, the nylon teeth on the 117-7756 Flange may get stripped by the 141-0666 Coupling Hub or the 141-0666 Hub Coupling may slide off the pump shaft.
Failure of the 117-7756 Flange results in the loss of all hydraulic power for 906 machines. This failure can occur within the first 35 hours or so of machine operation.
Solution:
Anytime there is a failure between the 117-7756 Flange (4) and the 141-0666 Coupling Hub (1), remove the flywheel (5) and check for the installation of the two dowel pins. See Illustrations 1 and 2.
Refer to Service Manual Module, SENR5013, "Disassembly and Assembly - 3034 Engine", section "Flywheel - Remove and Install" for detailed instructions.
- A. If the dowel pins are missing, install two 153-1013 Dowel Pins in order to locate the flywheel housing (6) properly onto the engine block.
NOTE: When reinstalling the flywheel (5), tighten the bolts to 100 ± 5 N·m (74 ± 4 lb ft).
- B. Ensure that the 141-0666 Coupling Hub (1) is correctly positioned on the splined shaft of the hydrostatic pump. The rear face of coupling hub (1) must be installed to a dimension of 8.6 ± 1 mm (0.34 ± 0.04 inch) from the front face of the hydrostatic pump. See Illustration 3.
NOTE: Service Manual Module SENR1285, "Disassembly and Assembly - 3024 & 3034 Engine Supplement for 902 and 906 Compact Wheel Loaders", section "Engine Rear Support Hub and Flange - Remove and Install" is out of date and no longer applicable. The module is being updated.
- C. Ensure that a thread lock compound is applied to the threads of the allen head screw (7) and the allen head screw (7) is tightened to a torque of 55 ± 5 N·m (41 ± 4 lb ft).
Illustration 1. View of the engine, flywheel housing, and pump mounting components.
Illustration 2. Location of dowels.
Illustration 3. Placement of coupling hub on splined shaft of the hydrostatic pump.
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