Spicer Drive Axles Failure Analysis Service Manual - Manual (Page 21)

Ring Gear and Pinion
20
R
ing G
ear and P
ini
on
Shock (Impact) Failure
Ring Gear - Catastrophic Failure Ring Gear - Coast Side Shock Failure
Drive Pinion - Torsional Shock Failure Drive Pinion - Tooth Shock Load Failure
General Description: Shock damage occurs from overstressing the gear teeth or shaft beyond the strength of the material.
The failure could be immediate (from a sudden shock) or progressive (cracking of the teeth or shaft
surface following the initial shock).
Usual Causes: • Rough trailer hook-up
• Spinning wheels grabbing on firm road surface
• Misuse of the inter-axle differential lockouts
• Trying to free-up frozen brakes
Failure Prevention: Vehicle Operation and Drive practices - see Failure Prevention Section.
Granular fracture
surface
Instantaneous
break, 45
o
angle