Sefac has issued the following advisory:

Go-no-go caliper for bronze nut wear control advisory

Please insert the go-no-go caliper between the bronze nut and steel safety nut. The caliper must fit in the gap. If it does not and the clearance is below .08 inches or 2mm replace both the bronze and steel safety nut. Do not operate the lift if the caliper does not fit in the gap.
Danger to the operator and lift could result!
Please check this gap at intervals of once every month!

Contact OLS Service for additional information.