FOR MODELS: JGW, JGR AND JGJ SECTION 5 - MAINTENANCE
PAGE 5 - 10 1/01
or one of the throws and the other hand on the end of the shaft to keep the
crankshaft level. Wear gloves to avoid being cut by the slinger and to achieve a
good grip. (As with each operation, the gloves should be clean to avoid marring
of the running surface.) As the shaft is being slowly raised, the drive and auxil-
iary ends should be lifted at the same rate. Again, care must be taken to avoid
marring the crankshaft surfaces by carefully guiding the crankshaft.
Crankshaft - Oil Slinger
Removal
Although the slinger should last indefinitely with proper care, it can become nicked. Should it
need replacement, suspend the crankshaft on a sling(s) as in “Crankshaft - Removal” on
page 5-8 and heat the slinger to 400°F (240°C). It will attain a yellow glow at this tempera-
ture. When it has expanded it should fall off by itself. DO NOT TOUCH HOT SURFACES
WITHOUT PROPER INSULATION TO PREVENT INJURY.
Installation
Put a rod at least 1/2 inches (13 mm) in diameter through the slinger. (Special care should
be exercised when handling the slinger, not only to keep its surfaces unmarred, but to avoid
being cut by the outer sharp edge.) After the slinger is suspended heat it with a small torch.
When it has attained a yellow glow, approximately 400°F (240°C), it can be slipped over the
drive end of the crankshaft. Hold the slinger in position with high temperature gloves or two
pieces of clean wood, rotating it slightly to make sure it is square, until it has cooled enough
to shrink onto the crankshaft. DO NOT TOUCH HOT SURFACES WITHOUT PROPER
INSULATION TO PREVENT INJURY.
Crankshaft - Chain Sprocket
Removal
Examine the sprocket carefully for signs of wear. If it has been in operation for five years or
more, it may be convenient to replace it if the crankshaft is removed from the frame.
Drill a hole in the sprocket hub. This hole should be parallel to the shaft centerline and big
enough that it removes most of the hub cross section. (See Figure 5-6:) Be careful not to
TABLE 5-1: APPROXIMATE WEIGHTS OF BARE CRANKSHAFTS
NUMBER OF THROWS POUNDS (kg)
2 210 (95)
4450 (200)
6950 (430)