Procedure for Checking Crankshaft End Play on Certain 794 and 795F Series AC Off-Highway Trucks {1201, 1202} Caterpillar

Off-Highway Truck/Tractor

794 AC (S/N: MN51-UP; MT51-UP)

795F AC (S/N: ERM1-UP)

Introduction

Do not perform any procedure in this Special Instruction until you have read the information and you understand the information.

Reference Section

Reference: Refer to Specifications"KENR9187""C175-16 Engine for 795F Series AC Off-Highway Trucks", Crankshaft -Type 1 and Crankshaft - Type 2 for crankshaft end play values.

Removal Procedure

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Illustration 1	g06163441

1. The fume disposal group may need to be removed for access to engine side cover. The covers at cylinders 15 and 16 typically have the least restriction to access due to engine-mounted equipment.
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2. The starter motors (electric or air) should also be removed to gain access to the engine cover.
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3. Remove cover to access crankshaft group.

Inspection Procedure

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1. Using a 36 inch handled pry bar (similar to 239-4255 Pry Bar) move the crankshaft to its forward most position such that it is up against the front thrust washer. Insert the end of the pry bar between the main bearing cap and the crankshaft counterweight.
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   Illustration 5	g06163450

2. A dial indicator on a magnetic base (for example, 8T-5096 Dial Indicator Test Group) should be positioned and zeroed on the oil pan rail of the block, in the crank window, damper, flywheel, or other location where the axial position/movement of the crankshaft can be measured. Ensure that the dial indicator plunger/spindle is positioned parallel with the crankshaft axis to provide the most accurate measurement.
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   Illustration 6	g06163452

3. Using the 36 inch handled pry bar, move the crankshaft rearward until it contacts the rear thrust washer. If excessive force is necessary, no movement, or springy motion of the crankshaft is observed, crankshaft axial motion is being restricted. Inspect components which interface with the crankshaft, such as the coupler group, for restricted axial compliance, improper assembly, or worn or damaged components.
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   Illustration 7	g06163453

4. Once the crankshaft is moved axially through its end play, record the value shown on the dial indicator and repeat in the opposite direction. The dial indicator should return to its zero reading.

5. Remove all tooling and reinstall any components removed to perform this measurement.