Cub Cadet MTD 70 Series - Manual (Page 112)

61/65/70/75 Series Horizontal Shaft Engines
106
Crank shaft inspection
1. Inspect the crank shaft journals for galling, scoring,
pitting or any other form of damage.
2. Measure the journals at the bearing contact points
using a vernier caliper or a micrometer. See Figure
10.7.
NOTE: Micrometers are the preferred and most
accurate way to measure the journals.
3. Inspect the crank pin for galling, scoring, pitting or
any other form of damage.
NOTE: This is mostly a visual check. Measurement
is to determine if it is within the specifications
after it is found to be OK visually.
4. Measure the crank pin using a vernier caliper or a
micrometer. See Figure 10.8.
5. Check the crank shaft for straightness by measuring
the run out. The crank shaft run out can be check
by:
5a. Place the crank shaft on a pair of matched V-
blocks or in the engine block with the sump
installed.
5b. Place a dial indicator at a smooth point at either
end of the crank shaft.
5c. Slowly turn the crank shaft while watching the
dial indicator.
NOTE: Stop the crank shaft before the dial indicator
hits the keyway.
5d. Compare the reading on the dial indicator to the specification listed at the end of this chapter.
5e. Repeat the above steps on the other end of the crank shaft.
Figure 10.7
Bearing contact
area
Figure 10.8
Crankpin