MOTOR TRUCK SERVICE MANUAL
Fig . 1-Scored and Scuffed Gear Teeth .
Scored and scuffed teeth such as those shown in Fig. 1
Excessive torque input can create sufficiently high tooth
are the result of running without sufficient lubricating film
pressures to cause even the best of lubricants with high
between the tooth surfaces.
film strength to be forced from between bevel teeth
resulting in scoring and scuffing.
Observe how the scuffed area is spread well over the
tooth area. Note the appearance of the scuffed area
Good quality recommended lubricant, changed at
suggesting the metal had reached the plastic stage and
recommended intervals, when torque input is not
was drawn across the tooth face. This condition is
excessive, will prevent costly repairs of this kind.
created by the metal-to-metal contact when there is no