Spicer Drive Axles Failure Analysis Service Manual - Manual (Page 40)

Seals and Yokes
39
Note: Reference Seal Maintenance Guide TCSM-0912.
General Description: A seal has two critical functions: to retain lube and to exclude dust and dirt. For proper function, the
seal must be correctly installed, clean, and free of defects.
Seal Inspection: Careful inspection of seal condition plays an important role in both routine maintenance and failure
analysis. Below are some conditions to look for. Check carefully as the smallest defect on the seal lip
could cause a leak. In general, any of these observed defects calls for a replacement seal.
• Check ofr damaged seal lip, bent outer shell, cups and nicks or scoring
• Examine seal edge. A new seal lip has a sharp edge. If sharp edge is flattened greatly, replace the seal.
• Check for hardness or a brittle or cracked lip. This condition is usually caused by excessive temper-
atures. If the seal lip area is not flexible, replace it.
• Check seal lip contact area. If the contact area is over 1/32", the seal may be excessively worn or the
material may have lost its consistency.
• Look for bonding separation of seal to outer shell. This could change the flexibility of the seal lip and
cause a leak.
• Check seal spring for fit of the seal on the yoke or low tension. The seal lip may have lost its tension
or consistency. Replace it.
• Check inside, under the seal lip, and the casing, for dirt between seal and bearing cage or an accumu-
lation of sludge and other contamination. The seal must be as clean as possible and void of foreign
contaminants.