A side shifter moves the whole carriage left and right so the operator can line a pallet up without repositioning the truck. A fork positioner moves the forks in and out so they match whatever pallet width turns up. Both are among the most useful attachments sold and both cost you rated capacity, which is the part dealers mention last. This guide explains what each one does, how the derate arises, what the law requires on the data plate, and how to decide whether the time saved is worth the capacity given up.
Get Free Quotes 👑Without a side shifter, lining the forks up with a pallet means moving the truck. The operator inches forward, reverses, adjusts, and tries again, and at any real height they cannot see the fork tips well enough to get it right first time. A side shifter gives typically three to five inches of travel each way, letting the operator square the forks to the pallet from a stationary truck. On a shift of a hundred and fifty picks, the seconds saved per pick add to real minutes, and the rack damage avoided adds to real money. At height, where visibility is worst, it is the difference between a confident placement and a guess.
A fork positioner hydraulically moves the forks together and apart from the operator seat, so a truck handling 48 inch pallets, 40 inch pallets and odd-sized crates in the same shift does not need anyone to climb down and manhandle forks along the carriage. Manually repositioning forks is slow, it is a recognised back injury and crush hazard, and in practice operators skip it and run badly spaced forks instead, which damages pallets and loads. A positioner removes the reason to skip it. Most positioners also side shift as a single integrated unit, which is usually the right way to buy both.
The derate comes from two causes that stack. First, the attachment has mass, and that mass hangs on the front of the truck where it works against the counterweight exactly like payload does. Second, the attachment pushes the load forward, moving the load centre further from the front axle. A side shifter typically adds one to two inches to the effective load centre and a fork positioner commonly more. Because capacity is calculated at a specific load centre, usually 24 inches, moving that centre forward reduces the rated capacity even before the attachment weight is counted.
As a working estimate, a side shifter commonly costs in the region of five to ten percent of rated capacity, and an integrated fork positioner and side shifter combination commonly costs more. The actual figure depends on the attachment weight, its thickness front to back, the truck and the lift height, so treat percentages as a planning number only. The number that counts is the one on the recalculated data plate for your specific truck and attachment combination, and you should insist on seeing it before you buy rather than after the truck is delivered.
The capacity plate on the truck must reflect the truck as it is actually configured, including attachments. Under 29 CFR 1910.178(a)(4) modifications and additions affecting capacity or safe operation require the manufacturer prior written approval, and under 1910.178(a)(5) capacity, operation and maintenance instruction plates must be changed to agree with that approval. In practice that means the truck maker, not the attachment vendor, issues the recalculated figures, and the plate on the truck gets updated. A truck running an attachment with an uncorrected plate is both an OSHA citation and a real stability risk, because the operator is working to a number that no longer applies.
A side shifter needs a third hydraulic function beyond lift and tilt. A fork positioner needs a third and often a fourth. Trucks are built with a set number of functions, and adding one later means a valve section, lines run up the mast, a hose reel or internal routing, and a control for the operator. Retrofitting is possible but it is not cheap and it is not quick, so if there is any chance you will want these attachments, specify the extra hydraulic functions when you order the truck. The incremental cost at build is a fraction of the retrofit cost.
A side shifter is worth it in almost any racking operation, and particularly above about 150 inches where fork tip visibility is poor. The capacity loss is modest and the placement accuracy and reduced rack damage pay for it quickly. A fork positioner is worth it when pallet sizes genuinely vary through the day, when you handle crates, machinery or non-standard loads, or when the alternative is operators manually shifting forks several times a shift. If every pallet you handle is the same GMA 48 by 40, a positioner is cost and derate you do not need.
Skip the attachment if you are already working near the truck rated capacity, because losing five to ten percent may put your heaviest regular load over the derated limit and the answer then is a bigger truck rather than a smaller attachment. Skip it on low-height floor stacking work, where the operator can see the fork tips and alignment is easy. And skip the positioner specifically if your loads are uniform, since it buys nothing and costs both capacity and hydraulic complexity. Buying the attachment and then discovering you cannot lift your own product is an expensive and common mistake.
Give the dealer your heaviest regular load, its dimensions, the load centre it implies, and your maximum lift height. Ask for the recalculated net capacity with the attachment fitted at that exact height, in writing, from the truck manufacturer. Confirm the attachment weight and its thickness front to back, since both drive the derate. Confirm the hydraulic functions are included at build rather than retrofitted. And confirm who issues the corrected data plate and that it arrives with the truck, because that plate is what an OSHA inspector will read and what your operator will rely on.
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Commonly in the region of five to ten percent of rated capacity, from the attachment weight plus the one to two inches it typically adds to the effective load centre. The real figure depends on the attachment and the truck, so insist on the recalculated data plate figure before buying.
A side shifter moves the whole carriage left and right so the operator can align with a pallet without moving the truck. A fork positioner moves the forks in and out to match different pallet widths. Many units combine both, which is usually the sensible way to buy them.
Yes. The capacity plate must reflect the truck as configured. OSHA requires the manufacturer prior written approval for modifications affecting capacity or safe operation, and requires the capacity and instruction plates to be changed to agree with that approval. The truck maker issues the figures, not the attachment vendor.
Usually yes, but it needs a spare hydraulic function, which means a valve section, lines up the mast and an operator control if the truck was not built with one. Retrofitting costs considerably more than specifying the function at build, and you still need manufacturer approval and a corrected data plate.
It is if your pallet sizes genuinely vary through the day, or you handle crates, machinery or non-standard loads, or operators would otherwise be manually shifting forks several times a shift. If every load is a standard 48 by 40 GMA pallet, it buys nothing and costs capacity.
If your heaviest regular load would exceed the derated capacity, yes. That is the correct answer rather than running the attachment near its limit. Work out the net capacity with the attachment at your maximum lift height first, then size the truck to that number.