How to maximise boom leaf chain life in telehandlers and MEWPs
Ensuring your boom leaf chain is in good health is of utmost importance to telehandler and mobile elevated work platform (MEWP) owners.
Proactive maintenance not only guarantees safe operation, it also hugely reduces the risk of unscheduled downtime and improves the total cost of ownership.
There are two specific maintenance issues that can lead to a reduction in telehandler boom leaf chain life – incorrect lubrication and over-tensioning.
In this blog post we explain the pitfalls of both – and we provide advice on the steps to take to ensure you are getting the very best out of your leaf chain maintenance procedures.
Ensure you’re using the correct lubrication
Friction corrosion, turned pins, metallic friction, stiff joints and noisy operation are all signs that something is amiss with your lubrication method. In many cases, the cause is due either to the use of an unsuitable lubricant or to improper application.
There can be some common pitfalls when it comes to choosing the right product. Many people, for example, don’t realise that most leaf chain lubricants are produced for transmission and motorcycle applications.
Telehandler and MEWP boom leaf chain requires a lubricant with entirely different properties. And as this equipment often has to operate outdoors, the lubricant needs to be a high enough quality to stay in place even when exposed to the elements.
If you are unsure about the correct choice of lubricant for your application it will be best to speak to the machine maker or a lubrication specialist to check you have selected the correct formula.
Purchasing the right lubricant, however, is just the first step.
Apply the lubricant correctly
Correct application of lubricant is another area in which people can sometimes fall short. Many telehandler and MEWP owners believe they are doing the right thing by applying lubricant regularly and generously – but there are other factors to consider.
The space limitation of the booms sliding over each other means that retraction and extension leaf chains are often flat and wide with multiple links – which can make lubrication difficult.
Boom leaf chains are often required to operate under constant tension, so it is important for the user to make sure the leaf chain is slack before applying the lubricant, so it can penetrate between the link plates and onto the leaf chain rivet pin.
It is also advisable to articulate the leaf chain directly after applying the lubricant so that it can work its way into the leaf chain joints before final leaf chain tensioning.
Be wary of over-tensioning
Another common cause of reduced leaf chain life in telehandler and MEWP booms is over-tensioning.
In most boom applications, the extension and retraction leaf chains act against each other, and tensioning slackens the leaf chain working in opposition.
Over-tensioning of boom leaf chains results in the leaf chain being preloaded. This means that when it is in operation, it will be bearing greater loads than it was designed for.
Just a few extra turns on the leaf chain adjustor nut could add up to an extra ton on the leaf chain load. One indication that a leaf chain is operating above its design load will be turned rivet pins on the section of leaf chain that wraps the leaf chain roller.
A simple way of keeping an eye on leaf chain tension is to periodically measure the distance the leaf chain sits in from the boom when unladen.
When adjusting the leaf chain, it may not be possible to carry out the full adjustment in one go – the boom may require an extend and retract cycle to allow the leaf chain’s system to balance out.
It is recommended that users consult the operational manual for the detailed leaf chain tension requirements for their specific machine.
Invest in a leaf chain wear gauge
Boom leaf chains are generally around 5 metres (16 feet) long and 80% to 90% of their length will articulate around the leaf chain roller, which generates leaf chain wear.
Once leaf chain has elongated by 3% or more, it is unsafe and needs to be replaced.
Investing in a chain wear gauge can be invaluable in aiding the detection of early wear and avoiding equipment failure.
The FB Professional Chain Wear Gauge is a user-friendly tool for measuring leaf chain wear in imperial pitch leaf chain, forklift leaf chain and roller chain.
It is widely used in the thorough examination of lifting equipment (in accordance with the LOLER and PUWER regulations) and allows service technicians to easily spot potential leaf chain failure long before the next service.
If you’d like to learn more about how you can prolong the life of your telehandler boom leaf chain then feel free to contact a member of our team for further advice.
