Spicer Drive Axles Failure Analysis Service Manual - Manual (Page 28)

Power Divider
27
Helical Side Gear - Shock Failure Output Side Gear - Shock Failure
Input Shaft - Torsional Shock Failure Output Shaft - Torsional Shock Failure
General Description: Shock damage occurs from overstressing the gear teeth or shaft beyond the strength of the material.
The failure can be immediate (as from a sudden shock) or progressive (as cracking of the teeth or shaft
surface following the initial shock).
Usual Causes: • Rough trailer hook-up
• Rough trailer hook-up
• Spinning wheels grabbing on firm road surface
• Misuse of the inter-axle differential lockouts
• Side stepping the clutch
Failure Prevention: • Vehicle Operation and Drive Practices - see Failure Prevention Section
Teeth failed
at root
Teeth failed 90
o
from each other
Twisted Spline