Industrial seal self study guide - SKF.com

Troubleshooting (cont...)
Out-of-Round Shaft
Early lip leakage is also a symptom that the shaft is out-of-round
(fig. 9i). Industry specifications are listed in the 457010 SKF Handbook
of Seals.
Causes
Inspect the shaft to see if it is out-of-round. Flat spots on the shaft
can also cause early lip leakage.
An out-of-round shaft can also
cause seal leakage (fig. 9i).
Corrective Actions
Check the shaft’s “roundness” by measuring with a micrometer in
three equally spaced points circumferentially near the location of the
seal. Tolerances should be within the allowable range for the shaft size.
Be sure the shaft is carbon or stainless steel, finished 8 to 17
micro-inch Ra (0.20μm to 0.43μm), with no machine lead. One
solution is to remove and resize or reshape the shaft first. Then
repair the shaft with either a Speedi-Sleeve or an SKF Large
Diameter Wear Sleeve.
Garter Spring Damage
Garter spring problems are easy to spot. The spring may be loose, or
out of the seal. The spring may pop out and damage the mechanical
components. Or, the spring may be missing (fig. 9j).
Garter spring problems are visible
and easy to spot (fig 9j).
Causes
Maybe the spring was never installed in the seal. Perhaps it was
dislodged from the seal prior to installation. Or maybe too much
shock was transmitted to the seal during installation.
Corrective Actions
The only solution is to install a replacement seal. But first, check
the spring on the new seal. It could have become dislodged during
packaging or shipment. If so, install the spring into the seal. Use
correct mounting tools and follow correct installation procedures.
Be sure to apply press fit force uniformly.
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