SkyTrak 8042 Operation Manual - Manual (Page 163)

General Maintenance
161 Model 8042 Rev. 11/03
Elongation
When the original length (3) of 12.00" (305 mm) per foot of new chain
has elongated from wear to a length (4) of 12.36" (313 mm), the chain
should be discarded and replaced.
It is important to measure the chain in the section that moves over the
sheaves because it receives the most frequent articulation. Measuring
the chain near its clevis terminals could give an inaccurate reading. The
ends of the chains, near the clevis terminal, will not have flexed as
frequently, if at all, as nearer the middle of the chains.
Measure across a span of 17 pins at the center of the extend chain.
Measure from pin center to pin center. Because the retract chain is
inside the boom you will not be able to measure the chain.
The maximum measurement allowed is 12.36" (313 mm). If the
measurement is more than 12.36" (313 mm), the chain should be
replaced.
MM2120
3
4