How to Adjust Vestil WTJ Truck-Bed Crane Boom Length for a Load

The hole that gives you more reach is the hole that cuts your capacity. On the Vestil WTJ family of truck-bed cargo jib cranes, the telescoping boom is pinned at one of two positions the manual calls point A and point B, and that pin is a configuration, not a preference. Vestil's own product description says the telescoping boom lets the operator choose extended reach or higher lifting capacity depending on the load and the application. Reach and capacity sit at opposite ends of the same pin.

That flips the order most people work in. You don't slide the boom out to where the pallet is and then look up what it can hold. The WTJ-2 manual puts the sequence in one line: adjust boom length as the application requires, and make sure the load does not exceed the capacity for the selected boom length. What follows is the reason the pin matters, how to pick it, the four steps to move it, and how to confirm you got it right before the hook takes weight.

Why the Pin Position Sets the Load Limit

The reason comes down to leverage. The boom is a lever arm mounted on a mast, and the load hanging from the hook is a weight acting at some horizontal distance from that mast. Multiply the weight by the distance and you get the load moment that the boom, the mast, the base and the truck mounting all have to resist. Lengthen the boom and the same weight now acts further out, so the moment climbs even though you never touched the load.

Because the mast, base and mounting don't change once the crane is on the truck, horizontal distance is the only variable the operator actually controls. Which is why rated capacity is tied to the selected boom length rather than to the crane as a whole. The structure can resist a certain moment, and a longer boom spends that allowance on distance instead of on weight. Vestil describes exactly this trade: extended reach or higher lifting capacity, depending on the load. The two don't arrive together.

You probably want the longer setting anyway. Reach is the reason a telescoping boom exists, and the short hole looks like a compromise you'd rather skip. I get that. But the pin is a trade, not a bonus: the longer setting is paid for with capacity. The moment you start with the hole and then look for a capacity figure that clears your load, you are working backward from a decision you already made. The chart is the cheaper place to start.

The swivel base and the manual hydraulic hand pump don't change the arithmetic. Swiveling moves the load around the mast. Pumping raises and lowers the boom, which changes height and, at a fixed boom length, how far out the hook sits. What the manual ties the load limit to, though, is the selected boom length, so the pinned position is the setting you sort out before anything else.

Choose the Hole From the Load Chart

Suppose a warehouse team needs to set a pallet a bit further out from the truck than their current pin position reaches. Before the boom moves, they estimate the load, including the slings or spreader hanging off the same hook, then read the capacity listed for the longer setting on that specific model's chart. If the longer setting's row covers the load, the pin change is justified. If it doesn't, the reach is not available for that pick.

If the load fits the longer setting, move the pin. If it doesn't, the longer setting is not an option for that load. The rating belongs to the selected length, so a different pin is not a workaround for a load that is over the row.

The numbers that settle it live on your model's plate and its specification page, not on a family-wide figure. Hook, boom and winch ratings differ across WTJ models, so a capacity someone quotes for one unit doesn't transfer to the crane bolted to your truck.

Adjust the Boom in Four Manual Steps

The WTJ-2 manual gives the sequence in four moves, and the order is not arbitrary. First, use the hand pump to bring the boom horizontal or level. Then remove the bolt and fasteners, or the hitch pin and clevis pin, depending on which hardware your unit carries.

With the hardware out, grasp the end of the telescoping boom and slide it until the holes line up with the holes at point A or point B. Reinstall the bolt and fasteners, or the clevis pin and the hitch pin, and the length is set. The manual names two pinned positions, A and B, and those are the settings the capacity applies to.

Scope matters. That sequence comes from the WTJ-2 vehicle-mounted cargo jib crane manual. Other models in the WTJ family may use different hardware or a different set of positions, so the steps that count are the ones in the manual that shipped with your unit.

What Matters at Each Adjustment Step

Leveling first isn't housekeeping. A level boom is easier to control when you slide the telescoping section, and it stops the inner section from fighting gravity while the pin is out of the holes.

Removing the hardware comes before moving anything because the pin is what locks the sections together. Nothing slides until it's out, so a boom that won't budge usually means the fastener is still in, not that the tube is stuck. The pump has one job in this sequence: getting the boom flat enough to work on. It isn't part of setting the length.

Aligning to A or B is the step that actually decides your capacity, because the hole you choose is the boom length. A hole that's close but not lined up isn't a setting. The fastener has to pass through cleanly. Reinstallation is the step people rush. Until the bolt and fasteners or the clevis pin and hitch pin are back in place, the boom is only resting at a length, not locked at one.

Confirm the Boom Length and Load Match

Two checks close this out. Look at the pin and confirm which point it passes through, A or B, since that's the configuration you'll be lifting under. Then compare the load against the capacity listed for that selected length in the model's specification section.

If capacity information is missing, or a label on the boom and the specification page don't agree, treat it as a documentation problem to settle against the current model plate and manual. Don't average the two figures and don't borrow a rating from a similar model. A capacity you can't trace to a document for your own unit isn't a number you can plan a lift around.

What If You Only Need a Little More Reach?

A short extension still lands you in a different pin position, which means a different capacity applies. How small the change feels has nothing to do with it. The crane doesn't know you moved the boom a few inches; it knows which hole the pin is through, and that's the row the chart gives you.

So if the load exceeds the capacity for the length you'd need to reach it, the answer isn't a longer boom. It's a different lifting plan: reposition the truck, break the load into smaller picks, or bring in equipment rated for what you're actually moving. Reach is something you buy when you specify the crane, not a free adjustment you spend on the day of the lift.