RJ 15 Rolling Jack: What It Is and How to Order One

The search phrase RJ 15 shows up in Iowa shop-equipment inquiries most often when a shop owner has already purchased a four-post drive-on and needs a rolling jack. That accessory is what lets the wheels come off the ground so brake, suspension, or tire work can happen on a lift that would otherwise only allow drive-on service. We are Auto Lift Services, an Iowa-based installer and parts distributor, and we quote an RJ 15 or an equivalent 15,000-pound-class rolling jack for drive-on lifts almost every week. Here is what to know before you order.

What an RJ 15 rolling jack does on a drive-on

A four-post drive-on lift is fantastic for alignment, tire rotation, fluid service, and general inspection, but it holds the vehicle by the tires. The moment the tech needs to pull a wheel, drop a brake caliper, or work a control arm, the tires have to leave the runway. That is exactly what a rolling jack does. It rolls along the runways, positions under a jacking point, and lifts the axle or unibody off the runway so wheels come free.

An RJ 15 in the general market is a 15,000-pound-capacity rolling jack sized for the heavier drive-on runways found in commercial shops. It sits between the runways on rails, rolls to the axle you need, and lifts hydraulically or pneumatically. For most heavy commercial four-post lifts we sell in Iowa, we quote a rolling jack from the outset because the shop will end up needing one within the first year anyway. Buying it upfront saves a second install visit and cleans up the invoice.

Matching an RJ 15 to your four-post runway width

Runway spacing is the first fit check. Rolling jacks are engineered to fit a specific range of runway centers, and a jack sized for a light home-storage four-post will not span the wider runways of a 14,000-pound commercial drive-on. The RJ 15 label typically corresponds to a jack designed for wider commercial spacing, which is why it appears in the search history of shops running heavy trucks and vans.

Before we quote a rolling jack we ask for the make and model of the four-post lift, the outside-to-outside runway measurement, and the runway width itself. Those three numbers tell us whether the RJ 15 or a different rolling jack model is the right pick. We have had customers assume any rolling jack rolls onto any runway and end up with a jack that binds on the first inch of travel. A three-minute check on the phone prevents that. If your shop is running a mixed fleet of four-post lifts from different manufacturers, we can spec one rolling jack that fits the newest and largest runway so it moves between bays cleanly.

Capacity: what the 15 in RJ 15 typically means

The 15 in a rolling-jack model name almost always refers to lifting capacity in thousands of pounds. A rolling jack rated at 15,000 pounds is the workhorse capacity for commercial drive-on lifts serving three-quarter- and one-ton pickups, vans with utility bodies, and light box trucks. That is exactly the class of vehicle you find in Iowa municipal fleets, plumbing and HVAC service shops, and the mid-size auto-service shops around Ames and Ankeny.

Fifteen thousand pounds is not the vehicle weight rating; it is the amount the jack itself can lift off the runway. That means either the axle you are picking up, or in some cases the entire unibody. When you split a 15,000-pound rolling jack under a truck that weighs 12,000, you are well inside the safety envelope. Sizing down to a smaller rolling jack on that same truck puts the jack at or above its rating every time you use it, which shortens hydraulic seal life and stresses the roller bearings. Buy the capacity you need for the trucks you actually service, and buy it once.

Air, hydraulics, and control layout on an RJ 15

Most commercial rolling jacks in the RJ 15 category are air-over-hydraulic. Shop air pressurizes the hydraulic reservoir, which drives the ram that lifts the saddle. That layout is popular because it keeps electric wiring off the jack itself, and every commercial shop already has a compressor. Minimum air pressure is usually 120 to 180 PSI depending on the manufacturer, and most Iowa shops with a decent two-stage compressor meet that spec easily.

Controls sit on top of the jack or on a handheld pendant. Both work; the handheld pendant is a little easier for shorter techs and for reaching under trucks. Safety locks are mechanical: the jack lifts, then drops onto a lock at fixed intervals so the hydraulic pressure isn’t the only thing holding the load. When we install a rolling jack we walk the shop through the lock procedure and the daily checks. Read our writeup on rolling jack maintenance for the recommended service intervals.

Installing an RJ 15 on Iowa shop lifts

Retrofitting a rolling jack onto an existing four-post is straightforward when the runway rails are prepped for it. Every commercial drive-on lift we sell has jack rails built into the runways from the factory. Older drive-on units may not, and in some cases the runway needs to be swapped or upgraded to accept the jack. That is a fitment question we answer before the purchase order goes out.

An install visit for a new rolling jack on an existing lift usually runs half a day. We roll in, lift the jack onto the rails, connect the air, cycle the hydraulics, test the safety locks, and hand the shop a signed compliance sheet. If we sold the four-post originally, we already know the runway spec and skip the fit-check step. If someone else sold it, we ask for the manufacturer’s tag or a photo of the runway end plates. Cities and county shops in central Iowa, from the Ames area east to Cedar Rapids, are our most common install stops for rolling jack retrofits.

A central-Iowa city shop story

A recent example: a city shop in Story County came to us for a new 14,000-pound drive-on to service their mix of pickups, plow trucks, and passenger buses. Their tech had spent years without a rolling jack, moving vehicles between a drive-on and a two-post whenever wheels needed to come off. That was 20 minutes of moving vehicles for every brake job. They added a rolling jack sized in the RJ 15 class at install, and their tech got that time back on every service ticket.

That is the payoff pattern we see over and over. The rolling jack is a small part of the total lift-and-accessory invoice, and it compounds into hours of tech time saved every month. For a city shop or a fleet running steady vehicle volume, the accessory pays for itself in a quarter or two. For a home-garage buyer working on a single vehicle every few weeks, the math is less compelling. That is why we recommend the rolling jack to commercial buyers by default and mention it to hobbyists as an optional upgrade.

Ordering an the lift through us

The fastest path to a quote is a phone call at 800-674-9302. Have the make and model of your four-post drive-on, runway spacing, and the heaviest axle you plan to pick up. We can confirm fitment, quote the jack and freight, and schedule install if you are inside our Iowa install radius. For customers outside Iowa we ship the rolling jack and coordinate a certified installer through our national network.

Every rolling jack we quote ships with the installation manual, safety-lock inspection card, and a spare seal kit for the first year of service. Parts for commercial rolling jacks stay in stock at our Ames warehouse, so a rebuild ten years from now is not a scavenger hunt. Browse our full drive-on lift and accessory selection in the Auto Lift Services store, or read our car lift installation guide for the full site-prep checklist.