Auto Lift Arms: Symmetric vs Asymmetric — A West Des Moines Buyer’s Checklist

A farm shop owner west of West Des Moines emailed us in the middle of harvest with a photo of his 30×40 pole building and one line of text: “I want an auto lift I can do brakes on without laying on gravel.” He runs a mixed fleet — a couple of grain trucks he farms out to a real shop, plus four pickups, two SUVs, his wife’s crossover, and a hired man’s car that always seems to need rotors. Brake work was the whole reason for the purchase. The question that took the longest to settle was not capacity or brand. It was whether he wanted symmetric or asymmetric arms. That single choice changes how the vehicle sits, how the doors open, and whether wheel-off work is comfortable or miserable.

What symmetric and asymmetric actually mean

Strip away the marketing and the difference is geometry. On a symmetric two-post, the columns face each other directly and all four arms are the same length. The vehicle sits centered between the columns, roughly half its weight forward of the posts and half behind. That is the classic truck-shop layout, and it is what you see in most heavy-duty bays. On an asymmetric unit, the columns are rotated inward — typically around 30 degrees — and the front arms are shorter than the rears. The vehicle sits back in the lift, with about a third of its length forward of the columns and two-thirds behind.

Why bother rotating the columns? Door clearance. With the vehicle set back and the posts turned, the driver’s door swings past the column instead of into it. On a symmetric setup, a car with long doors — think an older coupe or a two-door pickup — can have its door hit the post before it opens far enough to climb out. That is annoying once and infuriating the fortieth time. There is also a third category, sometimes called versymmetric, where the arms are configured so the same auto lift can be loaded either way depending on the vehicle. That flexibility costs a bit more but solves the “my fleet is half cars and half trucks” problem cleanly, which is exactly the situation most farm shops are in.

Brake work is what tips the scale

If you are buying primarily for brake service and rotor swaps, sit down and picture the job. You raise the vehicle to chest height, pull four wheels, and then you need to work at the hub with a caliper bracket bolt breaker bar, a rotor that is rusted to the hub, and probably a three-pound hammer. You need clear, unobstructed swing room at each corner. You also need to walk from corner to corner with a rotor in your hands.

Symmetric arms put the columns near the middle of the vehicle, which is generally out of the way of all four wheels. That is a genuine advantage for wheel-off work on a passenger car. Asymmetric arms, because the vehicle sits back, put the columns closer to the front wheels — not blocking them, but closer. In practice most techs do not find that a problem, and the payoff in door clearance is worth it if you are getting in and out of vehicles constantly. Where asymmetric wins outright for brake work is on unibody cars, because the shorter front arms reach the front pinch weld points more naturally without stretching. On a body-on-frame pickup, symmetric is usually the easier load. Our West Des Moines customer’s fleet leaned truck, so we ended up recommending a symmetric-capable configuration and moving on to the harder question, which was the building.

Checklist item one: measure the building before you shop

Nothing sinks a lift purchase faster than a ceiling. Write down four numbers before you look at a single product page. First, clear ceiling height at the lowest obstruction over the proposed bay — not the peak, the lowest truss, purlin, light, or unit heater. Second, the height of your tallest vehicle. Third, the width of the bay wall to wall. Fourth, the distance from the bay to your electrical panel.

A 30×40 pole building with 12-foot sidewalls is one of the most common shapes we work in around central Iowa, and it handles most two-post units comfortably — but only if you check the truss detail. Pole buildings often have a bottom chord or a scissor truss that eats a foot or more of usable height at the sidewall while the center is wide open. A standard overhead two-post needs roughly 12 feet of clear height for the crossbar; low-ceiling versions cut that down, and a floorplate model moves the crossover to the ground entirely. If your ceiling is genuinely tight, a four-post or a mid-rise scissor may be the better answer, and we walk through that comparison in our two-post versus four-post breakdown. Measure twice. We have had customers order a lift that physically would not stand up in their building, and freight both directions is not cheap.

Checklist item two: the concrete under your feet

New pole buildings usually have decent concrete, but “usually” is not a spec. Any two-post anchors into the slab, and the slab is what holds the columns plumb when a loaded pickup is six feet in the air. Most 10,000 lb two-post units call for a minimum of 4 to 4.25 inches of 3,000 PSI concrete with at least 28 days of cure. We prefer to see 5 or 6 inches, particularly in a shop building where the slab may have been poured over less-than-perfect base.

The failure mode we see most in farm shops is not thin concrete — it is a control joint or a construction seam running right where an anchor needs to go. Anchors need a minimum edge distance from any joint or crack, generally 6 inches or more depending on the anchor spec. If your bay has a joint down the middle, the layout has to shift. Also watch for slabs poured in cold weather without proper curing, and slabs with in-floor heat tubing. Radiant tube in the pour is common in newer Iowa shop buildings and it is a genuine hazard — drilling into a PEX loop turns a good day bad. If you have in-floor heat, find your as-built drawing or scan the slab before anybody picks up a hammer drill. We would rather reposition an auto lift by two feet than repair a heating loop.

Checklist item three: power, and yes, you need 220

“Do I need 220 volt?” comes up in nearly every conversation. For a commercial-grade two-post, the honest answer is yes — the power units are built around 208-230V single-phase motors, and that is what gives you a reasonable lift speed. Some home-garage units offer 110V options, and they work, but the raise takes noticeably longer and the motor works harder. In a farm shop where you already have 240V for a welder and a compressor, running one more dedicated circuit is not a big lift.

Size it to the nameplate, usually a 30-amp dedicated circuit, and put a disconnect within sight of the power unit. Do not tap the welder receptacle. Do not share with the compressor. Voltage sag from a compressor start makes a hydraulic power unit sound like it is dying, and we have driven out to diagnose “broken” equipment that was just starving for volts. You will also need a shop air drop near the power unit column, because most two-post designs use a pneumatic lock release. A quarter-inch line is plenty. Get both the circuit and the air run before install day. If you want the full pre-install punch list, our installation checklist article lays it out step by step, and we go over it on the phone with every customer before we schedule.

Checklist item four: capacity, arm reach, and adapters

Capacity is easier than people make it. Add up your heaviest vehicle at its heaviest — full fuel, tools, topper, ladder rack — then give yourself margin. A 10,000 lb two-post covers essentially every half-ton and three-quarter-ton pickup, every SUV, and every car. Step to 12,000 lb if you regularly work on one-ton duallies with service bodies. Anything above that and we are talking about a different class of equipment entirely.

Arm reach matters more than raw capacity for a mixed fleet. Three-stage front arms telescope farther, which is what you need to reach the frame lift points on a crew cab long bed. Short two-stage arms will leave you stretching. On the other end, a low-profile sports car or a lowered pickup needs arms that go thin enough to slide underneath — that is where drop-in truck adapters and low-profile pads earn their keep. Buy the adapter set with the lift, not later. Frame cradle pads for body-on-frame trucks, stackable adapters for tall pickups, and rubber pinch-weld pads for unibody cars will cover ninety percent of what rolls through a farm shop. Our West Des Moines customer added a set of stackable truck adapters and told us later it was the best hundred-and-change he spent on the whole project. The right pads turn an okay auto lift into one that fits everything you own.

Checklist item five: who installs it, and what happens after

You can bolt a two-post down yourself. Plenty of people do. What you cannot easily do yourself is verify anchor torque against spec, shim columns to true plumb across both axes, bleed the hydraulics correctly, set cable equalization, and confirm the lock mechanisms engage simultaneously on both carriages. Those five things are the difference between equipment that runs for twenty years and equipment that drifts, binds, and chews cables. Our install crew does all of it and leaves you with documented anchor torque and a level report.

After install, the maintenance is light but non-negotiable. Check cable tension and carriage level at thirty days — cables stretch during break-in, always. Then quarterly. Keep the hydraulic reservoir topped with the correct fluid, grease the sheaves, and wipe the columns. Once a year, get an ALI-standard inspection; even in a private farm shop where no regulator will ever visit, that inspection catches worn arm pins and loosening anchors before they matter. And keep a couple of spares on the shelf — arm pads and a lock spring kit cost very little and prevent a week of downtime during planting or harvest when you cannot afford it. We stock parts for every brand of auto lift we sell and most of the ones we do not, and we ship anywhere in Iowa. If you are still deciding between configurations, call us. Ten minutes on the phone beats a wrong order every time.