WEICHAI WD10 Service Manual - page 78
Service Manual for WD10 Diesel Engine
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4422 Steps to Disassemble Piston-Rod Assembly
(1) Remove circlip on two sides of piston with internal circlip plier and push piston pin out, take
down the connecting rod body. Number the piston pins, connecting rod bodies and place them
orderly.
(2) Remove first compression ring, second compression ring and oil ring with piston ring plier and
mark them.
4423 Inspection and Maintenance of Piston-Rod Assembly
(1) Check whether there is crack on combustor throat fillet and piston pin boss; Check piston skirt
and piston head for cylinder scoring phenomenon; Check wear condition of piston pin hole.
(2) Check wear condition of piston ring outer edge; Check wear condition of piston ring upper and
lower end face.
(3) Check wear condition of piston pin external surface.
(4) Check whether there is crack on connecting rod big end bottom hole, connecting rod body and
connecting rod small end oil hole; Check alloy layer of connecting rod shell for abnormal wear
and peeling phenomenon; Check wear condition of connecting rod side faces, check crooking
condition of connecting rod body.
(5) Check wear condition of connecting rod bearing shell, check its alloy layer for discoloration,
peeling and slippage phenomenon.
4424 Steps to Assemble Piston-Rod Assembly
(1) Install one circlip into piston circlip groove with internal circlip plier, and rotate the circlip to
ensure it is properly fitted. The end with corner angle should face inward, and its opening
should be upward.
(2) Insert small end of connecting rod into piston inner cavity and align it to piston pin holes, and
then install piston pin, finally install the other circlip to the other side of the piston. Note that
connecting rod oblique incision and piston cooling oil gallery inlet should be in the same
direction, apply proper clean lubricating oil on connecting rod small end hole and piston pin.
(3) Arrange the assembled piston-rod assembly in cylinder number order, and then install oil ring,
second compression ring and first compression ring into piston ring grooves orderly with piston
ring plier. The face with mark “TOP” should be upward, and the ring should be flexible in ring
groove.
(4) Clean up cylinder inner wall, crankshaft connecting lever and piston-rod assembly, and apply
clean lubricating oil on each motion pair.