A Year With a New Lift: Symmetric vs Asymmetric Arms at an Urbandale RV Shop

The owner of an RV and trailer service shop in Urbandale spent most of a winter arguing with himself about arm configuration before he let us install anything. He does bumper-pull and gooseneck trailer repair, some chassis and frame work on Class C motorhomes, and a growing amount of restoration and metal fabrication on older tow vehicles. His question was the one we hear constantly: for that kind of mixed, long-wheelbase, welding-heavy work, does a hydraulic lift automotive setup want symmetric or asymmetric arms? A year later he has an opinion, we have a service history on the machine, and both are worth sharing because the textbook answer and the shop-floor answer are not quite the same.

The Shop, the Vehicle Mix, and Why the Decision Was Hard

Walk into this Urbandale building on a Tuesday and you might find a 24-foot enclosed cargo trailer on jack stands, a three-quarter-ton crew cab waiting on a rear axle seal, and a 1970s pickup cab stripped to bare metal on a cart. That mix is exactly what makes the arm question tricky. Trailers themselves rarely go on a two-post, but the tow vehicles do, constantly. Long-bed crew cabs, service vans, and dually trucks are the daily bread. Meanwhile the restoration side means techs are in and out of cabs and doors all day with grinders, welding leads, and panels.

Symmetric columns face each other squarely and split the load 50/50 front to rear, which is friendly to long wheelbases and heavy front ends. Asymmetric columns rotate roughly 30 degrees with short rear arms and long front arms, positioning the vehicle behind the columns so doors swing clear. For a shop doing mostly cars and light trucks, asymmetric wins on convenience. For a shop where a long-bed truck’s center of gravity is the daily concern, symmetric is more forgiving. The owner wanted both answers at once, and honestly that is a legitimate position — it just means you buy for the majority of your work and use adapters for the rest.

What We Recommended and Why

We recommended a 12,000 lb symmetric two-post with long three-stage arms and a truck adapter set, with the columns spread wide enough to take a dually through. The reasoning was straightforward. When the heaviest and longest vehicles on your schedule are the ones that scare you, buy the configuration that handles those well and accept slightly tighter door clearance on the occasional sedan. A restoration project sitting on a lift for three weeks is also a load balance question, and symmetric arms let you place pads at true frame points on an old body-on-frame truck without stretching a long front arm to its limit.

The clearfloor overhead version fit because his ceiling measured just over 13 feet to the bottom of the joists — plenty. We did recommend against putting the machine in the bay he originally wanted, which was directly under a run of low ductwork and only nine feet from a slab control joint. Moving it two bays over cost nothing at install time and avoided a compromise he would have cursed weekly. For his second bay he added a mid-rise scissor later in the year, which turned out to be the sleeper hit of the whole project. Any hydraulic lift automotive plan should account for the quick jobs, not just the big ones.

Install Week: Concrete, Anchors, and One Surprise

The building is a 1980s metal structure with an addition, and as usual the two halves of the slab were not the same. Core samples showed a solid five inches where we wanted the lift and about three and a quarter inches in the addition — which is exactly why we core rather than trust a blueprint. Two-post anchoring wants a minimum of four inches of 3,000 PSI concrete fully cured, with proper distance from edges and joints. Had he insisted on the original location, we would have been cutting out a section and pouring a footing pad before a single anchor went in.

Install itself took most of a day: setting and squaring columns, plumbing them, torquing anchors to spec, routing the equalization cables and hydraulic hose, wiring the 220V single-phase power unit, then bleeding the system and cycling it under load. We test every lock position by ear and by feel, confirm both carriages rise within tolerance of each other, and then spend twenty minutes on training that nobody thinks they need. The daily walk-around, the monthly cable and anchor check, the manual lowering procedure for when a vehicle is up and the power is not — that last one has saved more shops than any other thing we teach. We wrote it on a laminated card and zip-tied it to the column.

Months One Through Four: Learning the Arms

The first month was mostly the crew relearning muscle memory. Symmetric arms mean the driver’s door lands close to the column, so techs got in the habit of setting the vehicle a few inches farther forward and opening the door before raising. Nobody loved it at first. By month two they had stopped mentioning it, which is how you know a piece of equipment got absorbed into the routine. What they did love immediately was how planted a long-bed crew cab sat — no more of the nose-heavy nervousness they had lived with on an older undersized machine.

Restoration work exposed a different lesson. Grinding sparks and weld spatter are hard on hydraulic hoses, rubber pads, and cable sheaves. Within six weeks he had a scorched pad and a hose jacket with a burn mark on it. We showed him how to hang a welding blanket over the hose run and keep a spare set of pads on the shelf, both of which are five-minute habits that prevent a real problem. If you do metal work over a hydraulic lift automotive setup, treat hose protection as part of the job, not an afterthought. We have replaced hoses on shops that learned that the expensive way.

The First Real Service Call

Around month seven he called with the classic symptom: one carriage was sitting maybe an inch and a half lower than the other in the morning, and the pump seemed to labor at the top of travel. That combination almost always points to either a cylinder seal bypassing internally or a stretched equalization cable — sometimes both, since one causes the other over time. We put it on the schedule for the following morning. Fluid was down slightly, there was a light film on the cylinder rod, and the cable tension on the low side had gone soft.

Fix was a seal kit, fresh fluid, and re-tensioning both cables to spec, then cycling and re-verifying lock engagement. Total time on site was about three hours and the parts were a few hundred dollars. We see the same story constantly from shops all over the country: a four-post whose ram is leaking internally and bypassing, or a machine that simply will not go up or down because the lowering valve is stuck. Both are routine repairs on well-supported brands and both are miserable on orphan equipment nobody stocks parts for. This is the part of the buying decision that nobody weighs correctly on day one. Our parts lookup exists because so many shops call us with a serial plate and a photo, and that is genuinely enough to get most of them the right cylinder or valve.

Would He Choose Symmetric Again?

Asked at the one-year mark, he said yes for that bay and no for the next one. His plan going forward is symmetric for the truck and RV chassis side and asymmetric for the second two-post he wants for lighter tow vehicles and customer cars, where door access matters more than long-wheelbase balance. That is exactly the right conclusion, and it is the one we push most mixed shops toward: match each bay to the work that actually rolls into it rather than hunting for a single universal answer.

A few smaller lessons from the year. The mid-rise scissor absorbed far more work than expected, particularly wheels, brakes, and quick underbody looks, and it kept the big lift free for jobs that tie up a bay for days. Truck adapters got used more than he predicted and he wishes he had bought a second set. And the habit of a five-minute Friday walk-around — cables, anchors, hose, pads, fluid level, lock engagement — caught the drifting carriage before it became an emergency. If you are weighing symmetric against asymmetric for your own building, call us at 800-674-9302. We would rather spend twenty minutes on the phone about your vehicle mix than install the wrong hydraulic lift automotive configuration and hear about it a year later.

What to Nail Down Before You Sign Anything

Get four numbers before you buy: true clear ceiling height measured under the lowest obstruction, slab thickness confirmed by core sample if the building is older than you are, available electrical service at the panel, and the heaviest and longest vehicle you realistically expect to lift in the next five years. Those four numbers eliminate most bad decisions. Then confirm the lift carries an ALI certification plate and that the manufacturer — Rotary and Challenger on the commercial side, BendPak and Atlas for lighter and home-garage duty — has a real parts pipeline behind it.

Finally, budget for the accessories in the same conversation as the lift. Pads and adapters, a set of frame cradles, drip trays if you do a lot of fluid work, and a spare seal kit and lock latch kit on the shelf. Those items are a small percentage of the total and they are the difference between a machine that runs for fifteen years and one that sits idle waiting on a part. A hydraulic lift automotive purchase is really a fifteen-year service relationship in disguise, and the shops that treat it that way from day one are the ones who never call us in a panic with a car stuck in the air.