BendPak 4-Post Alignment Lift: Installation Prep and Site Survey Deep-Dive

A BendPak 4-post alignment lift is only as good as the concrete and clearance you set it on, and we learned that lesson again recently helping a third-generation family shop in Iowa City plan a bay swap around wheel bearing service. The shop had been doing bearing jobs on jack stands for two generations, but the volume of alignment and suspension work finally justified a real four-post setup with runways long enough to roll a car up, drop the arms, and get true four-wheel alignment geometry. Before anyone bolted anything down, we walked the bay with a tape measure, a level, and a slab questionnaire, because a lift this size does not forgive guesswork.

Measuring the Bay Before You Order Anything

Every BendPak 4-post alignment lift has a footprint that’s longer than most techs expect once you add runway length, approach ramps, and swing clearance for turning the car in and out of the bay. For a standard 9,000 to 10,000 lb capacity unit with alignment-ready runways, we’re typically looking at 18 to 20 feet of usable floor length and a minimum bay width of 12 feet, though 14 feet gives you room to walk around the vehicle comfortably. The Iowa City shop had an older two-bay building with a support column roughly at the 15-foot mark, which meant we had to shift the entire layout toward the overhead door rather than centering it in the bay.

Ceiling height is the other number people underestimate. With the platform up, alignment turntables installed, and a raised vehicle on top, you need real clearance above the vehicle’s highest point plus the lift structure itself — figure 12 feet minimum for most four-post alignment configurations, more if the shop runs taller trucks. We also checked overhead obstructions like ductwork, lighting, and door tracks, because a garage door track running at 10 feet 6 inches will clip a raised pickup before the lift ever reaches full height. Getting these measurements right before ordering saves a return trip and a very awkward conversation about restocking fees.

Slab Thickness and Anchoring Requirements

Every four-post installation we do in Iowa starts with a concrete evaluation, because a bendpak 4-post alignment lift transmits significant point loads through its columns and runway supports even though it’s a freestanding design that doesn’t always require the same anchoring as a two-post lift. Most manufacturers still specify a minimum slab thickness of 4 inches of properly cured concrete, doweled or reinforced, and rated to at least 3,000 PSI. Older Iowa shop buildings, especially ones poured in the 1960s through 1980s, often have thinner or cracked slabs near doorways where truck traffic has beaten down the surface over decades.

At the Iowa City shop, the original slab measured just under 4 inches near the front of the bay where delivery trucks used to back in, tapering to nearly 5 inches toward the rear wall. We recommended repouring a 6-by-14-foot section under the lift footprint rather than risking a marginal install, and we coordinated the timeline so the concrete had adequate cure time before the crew arrived with the lift. Skipping this step is the single most common reason four-post lifts settle unevenly or develop runway alignment problems within the first year, and it’s far cheaper to fix before delivery than after.

Runway Length, Width, and Alignment Turntable Placement

Alignment work adds a layer of precision that a standard storage or service four-post doesn’t need. The runways on a BendPak 4-post alignment lift built for this purpose include recessed turntable pockets at the front and slip plates at the rear, positioned to match the wheelbase range of the vehicles the shop actually services. We measured the wheelbase spread across the Iowa City shop’s typical customer mix — everything from compact sedans to full-size trucks — and confirmed the turntable spacing on the quoted model would accommodate that range without needing a second set of plates.

Runway width matters just as much as length. Narrow runways save floor space but make it harder to position wider trucks or dual-rear-wheel vehicles squarely for accurate alignment readings. We generally recommend the wider runway option whenever a shop’s bay allows for it, since the cost difference is minor compared to redoing an install because techs are constantly nudging vehicles to keep tires centered. The Iowa City shop opted for standard width given their space constraints, and we documented exact turntable and slip plate positions in the survey so the alignment equipment installer had precise reference points on install day.

Power Requirements and Hydraulic Layout

Most BendPak 4-post alignment lift models run on a single-phase power supply, but the amperage draw and circuit requirements vary by motor size and lift configuration, so this gets confirmed during the site survey rather than assumed. The Iowa City building had an older electrical panel with limited spare capacity, so we flagged the need for an electrician to add a dedicated circuit before install day rather than discovering the problem with a lift sitting half-assembled in the bay. This is a recurring theme in older Iowa shop buildings — electrical infrastructure from decades past rarely anticipated modern lift equipment.

We also mapped out where the power unit and hydraulic lines would run relative to the lift columns, keeping cables and hoses clear of the walking path around the vehicle. On a four-post platform, the hydraulic cylinder is typically housed within one of the rear columns, and the lines running to it need routing that won’t get pinched by a rolling jack or damaged by foot traffic. Planning this during the survey rather than improvising it during install keeps the finished job looking clean and keeps hydraulic lines protected for the life of the equipment.

Approach Angle and Ramp Considerations

Getting a low sports car or a lowered daily driver onto a four-post lift without scraping the front bumper requires attention to approach angle, and this is a detail that gets missed when people order a lift based on capacity alone. We asked the Iowa City shop what percentage of their alignment work involves lowered vehicles, since that changes which ramp or approach ramp configuration makes sense. Standard bolt-on approach ramps work fine for typical ride heights, but shops that regularly see modified vehicles benefit from low-profile or adjustable approach options.

We also looked at the transition from the shop floor to the base of the ramps, since even a small lip or uneven concrete seam can cause a scrape that a customer will absolutely notice and mention. Part of our site survey process includes checking floor flatness within the footprint using a long level, not just spot-checking a few points. Small dips get shimmed or addressed during the concrete work phase rather than discovered on delivery day when a customer’s car is sitting at the shop door waiting to be the first vehicle up on the new equipment.

Locking Mechanisms and Safety Clearance for Wheel Bearing Work

Wheel bearing service specifically benefits from the stability of a four-post platform because techs are applying significant torque and impact force to hub assemblies while the vehicle sits at a comfortable working height. We walked the Iowa City crew through the mechanical locking system on the quoted lift, showing where the locks engage along the columns and how many lock positions are available across the lift’s travel range. For bearing work, having a lock position that puts the wheel at a comfortable working height for a tech using an air impact and a press is worth discussing during the quote stage rather than assuming any height will do.

We also reviewed clearance around the columns for rolling jacks, since some wheel bearing jobs require lifting an individual corner off the runway to pull a wheel free while the rest of the vehicle stays supported. Not every four-post design accommodates a jacking beam or rolling bridge jack equally well, so we confirmed the quoted model’s compatibility with the shop’s existing jack inventory before finalizing the order. These are the kinds of details that separate a lift that works well for one shop’s actual workflow from one that just meets a generic capacity spec.

Delivery Logistics and Final Walkthrough

Once the concrete was cured and the electrical work was scheduled, we finalized delivery logistics with the Iowa City shop, confirming loading dock access, whether a forklift would be needed to unload crated components, and the exact date the crew would arrive for assembly. Four-post lifts ship in multiple crates — columns, runways, hydraulic components, and hardware — and having a clear unloading and staging plan keeps installation day moving instead of stalling out while people figure out where to put an 800-pound crate.

We did a final walkthrough with the shop owner before scheduling delivery, reviewing every measurement from the original site survey against the as-built conditions, since concrete work and electrical changes sometimes shift things slightly from the initial plan. This final check caught a minor discrepancy in ramp clearance near the bay’s side wall that we adjusted before the crew arrived. That kind of thoroughness is why a proper site survey matters as much as the equipment itself — a bendpak 4-post alignment lift installed without one is a lift installed on hope, and hope isn’t a great foundation for a piece of equipment holding a customer’s truck twelve feet in the air.