Main Lifting Spring - Dock Levelers

If you're manually operated dock leveler won't go up. The first place to look is the main extension spring. These springs are responsible for lifting the deck when pulling the activation chain.

Main dock leveler spring large extension spring under dock board

The overall length of your dock leveler extension spring is measured from the inside, hook-to-hook. This may require a small amount of estimation, as your spring may have a broken hook. Typical lengths will generally range from 18" to 32".

The outside diameter of your spring is a critical dimension. Be sure to precisely measure to within 1/8". The typical OD (outside diameter) for this type of spring will fall somewhere between 2.75" and 4".

Coil count is typically the easiest to find. Simply count the coils from one end to the other. You might find that a half-wrap on either end of the spring will make your coil count vary by 1 (or maybe 2) coils. You will find that most main-springs for, pit mounted levelers, will range from 20 to 30 coils on average. 

Lastly, the coil diameter. This will require you to perform some basic math. Count 10 coils, and measure the length of the counted coils. For example, if your measurement of 10 coils comes to 4.4", you would take 4.4/10 = .44". 

Consult your owner's manual for the correct part number, and always follow the safety precautions perscribed by your equipment manufacturer. Be sure to use our search feature to narrow down the precise spring you're looking for.