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Fretting Fatigue:
A Form of Mechanical Failure
Figure 1
Figure 1 is a view of the underside of the
vehicle. There was no evidence of direct
damage to the transmission or neighboring parts of the vehicle structure.
Figure 2
Figures 2 and 3 show views of a splined
driveshaft connection at the transmission.
The splines had worn to the point where
power could not be transmitted and the
connection began to slip. In Figure 2, the
arrow points to the worn splines. Figure 3
shows the mating part of the splined connection. The upper red arrow in Figure
3 points to worn splines on the mating
shaft. The original shape of the splines is
indicated by the lower blue arrow.
An insured struck a deer with his automobile, and
the damage was repaired. Shortly afterward, the vehicle
transmission failed, leading to an expensive repair. The
insured claimed the transmission failure was a result of
the impact with the deer. This precipitated a detailed
inspection of the vehicle and transmission.
