Dismantling; Inspecting The Crankshaft - Husqvarna 326 E Workshop Manual

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The task of the crankshaft is to transform the reciprocating motion of the piston to rotation. This requires a
stable design withstanding immense pressure and rotational and bending strain, as well as high rotational
speed. In addition the connecting rod is exposed to large acceleration and retardation forces as it moves bet-
ween the top and bottom dead centres. This puts special demands on the bearings that must withstand quick
changes in load. Moreover, the bearing's roller retainer must also cope with high temperatures and friction. It
is therefore extremely important when servicing to check the roller retainer for cracks, wear and discoloura-
tion caused by overheating.
The crankshaft is journalled in the crankcase on heavy-duty ball bearings. In addition to the journalling point
for the crankshaft, the crankcase acts as a scavenging pump for the fuel/air mixture when this is "sucked"
from the carburettor and is forced into the cylinder's combustion chamber. The crankcase must be perfectly
sealed so as not to aff ect this pump function. There cannot be any leakage from the crankshaft, between the
crankcase halves or between the crankcase and the cylinder.
Always replace the sealing rings and gaskets when servicing the crankcase.
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Crankshaft and crankcase
Alternativ

Inspecting the crankshaft

Inspect the large end of the connecting
rod.
Inspect the small end of the connecting
rod.

Dismantling

Dismantle all components so that only the
crankcase and crankshaft remain.
See the respective sections for detailed
information if necessary.
Now lift the crankshaft out of the crank-
case.
Remove the bearings (sliding fi t).
Remove the gasket residue from the base
of the cylinder and crankcase.
Inspecting the crankshaft
The crankshaft cannot be reconditioned
but must be replaced if it is worn or dama-
ged.
Inspect the large end of the connecting
rod. If seizure marks, discolouration on
the sides or damaged needle holders are
found the crankshaft must be replaced.
Inspect the small end of the connecting
rod.
If seizure marks or discolouration are
found in the bearing track the crankshaft
must be replaced.