Service Manual

Camshaft and Bearing (Fig. 65, 66)
1. Inspect the camshaft for evidence of severe wear.
2. Using a micrometer and a hole gauge, measure the
c
learance between the camshaft journals and the cylin-
der block. If the clearance is greater than 0.0059 inch
(0.15 mm) the camshaft or the camshaft bushing must
be r
eplaced.
3. To remove the camshaft bushing in the cylinder block,
carefully drive the bushing from its location using the
camshaft bushing tool (refer to “Special Tools”).
NOTE: You must drive the bushing into the cylinder
bloc
k and then crush it to remove it. Be careful not to
damage the valve lifter hole when removing the cam-
shaft bushing.
4. To install a new camshaft bushing use the camshaft
bushin
g tool and drive the bushing in from the outside
of the cylinder block being careful to align the oil delivery
hole in the cylinder block with the oil hole in the bushing.
5. If the cam surface is damaged or the cam lobe is badly
wo
rn it must be replaced. Cam lobe height should be
measured using a micrometer. The standard cam lobe
height for both intake and exhaust valves is 1.4079
inches (35.75 mm). The maximum allowable wear on
cam surface is 0.0394 inch (1.0 mm). Replace the
camshaft if wear exceeds this amount.
Figure 65
Removing camshaft bushing
Figure 66
Measuring camshaft cam lobe height
Fuel Injection Pump Camshaft (Fig. 67)
1. Inspect the camshaft bearing, replace if defective.
2. Examine the oil pump coupling. The camshaft must
be r
eplaced if this coupling is worn.
3. Examine the cam lobe surfaces. Replace the cam if
they are damaged.
4. Measure the cam lobe height in the same manner as
measuring the valve camshaft lobe height. The standard
lobe height for each cylinder of the injection pump is
1.7323 inches (44 mm). The camshaft must be replaced
if the cam lobe has been worn by 0.0394 inch (1 mm)
or more.
Figure 67
Fuel injection pump camshaft
Groundsmaster
®
300 Series Page 4 - 55 Cylinder Block Overhaul