Main lift chain system – 7120

Chain inspection

12.3.4 Stiff links

If it is not possible to pull out the chain to its normal position this can be because of link rust or seizing. The chain should be replaced.

12.3.5 Bolt rotation

Bolt rotation can be a phenomenon of stiff links. The fault is easy to see when comparing with a new chain. The chain should be replaced

12.3.6 Loose bolts

If a bolt is loose it will protrude from the side of the chain, which is due to a stiff link or bolt rotation. The chain should be replaced.

12.3.7 Outline wear

P = Pitch

H2 = Nominal disc height

H3 = Minimum disc height

A new lift chain has a specific nominal disc height, defined as H2 in the figure. As the truck is used the lift chain wears radically, on the side that runs over the chain sprocket. The minimum disc height is define as H3 in the figure and denotes the minimum permitted value of the disc height.

Maximal permitted outline wear is 5% of the height H2. If a lift chain reaches the maximum level of wear, the chain should be replaced. The nominal and minimum disc heights for respective lift chains are stated in the table in the chapter “Stretching”.