Understanding Weight Capacities: How to Safely Use Your Two-Post Lift
An automotive lift is one of the most important pieces of equipment you’ll ever own in your shop. However, not all lifts are made equal, and knowing the weight capacity you need is essential. If you misjudge your required weight capacity, you risk damaging the equipment, the vehicle, yourself, and others.
While there are various types of lifts, including mobile, inground, and four-post, two-post lifts are by far the most frequently used type in modern automotive shops. So, we’ll specifically focus on two-post lifts in this blog.
Typical Weight Capacity of a Two-Post Lift
Most two-post lifts can lift Class 1 through Class 5 vehicles, so the average weight capacity range for a two-post lift is between 7,000 and 20,000 pounds. Additionally, each arm has a maximum lifting capacity in addition to the total lift capacity. However, all manufacturers are different, so be sure you check the lifting capacity, including arm capacity, for any product you’re interested in purchasing.
So, as an example, a two-post lift with a maximum capacity of 10,000 pounds can handle 2,500 pounds on each arm. Thus, if you have a 9,000-pound vehicle with a 3,000-pound front axle and a 6,000-pound rear axle, you won’t be able to lift it. Since the rear axle is 6,000 pounds, that means 3,000 pounds will be on each arm. The maximum weight of each arm is 2,500 pounds, so the vehicle exceeds the allowable weight for the lift. To lift this vehicle, you would need a lift with a maximum lift capacity of 12,000 pounds.
Determining What Capacity You Need
- Determine the weight of the rear axle: Multiply the vehicle’s total weight by the distance from the center of gravity to the front axle. Divide this number by the wheelbase.
- Determine the weight of the front axle: Subtract the weight of the rear axle from the total weight of the vehicle.
To determine the weight allowable for each arm, divide the weight of each axle by 2.
So, if the average vehicle you work on is 10,000 pounds, but the rear axle is 6,000 pounds, you will need, at a minimum, a 12,000-pound lift. It is always better to go higher than you need, as several factors can change the weight of the vehicle, such as modifications, attachments, and oversized tires. Most manufacturers even recommend that you don’t exceed 75% of the lift’s capacity.
General Safe Use Practices for Two-Post Lifts
1. Never Exceed the Lift’s Weight Capacity
When lifting a vehicle that weighs more than the lift’s capacity, including each arm’s maximum capacity, you could experience lift failure, including bent arms that could cause the vehicle to shift and fall off the lift. Exceeding the capacity will not only damage the lift and the customer’s vehicle but also potentially cause severe injury or death to yourself and others in the area.
2. Ensure Proper Positioning
If the vehicle is not positioned properly, the weight distribution will be off, and the vehicle may not balance properly on the lift. Additionally, one or more arms could have excess weight, causing failure.
3. Maintain Your Lift When Needed
Always maintain your lift based on the manufacturer’s recommendations. Listen for unusual sounds, make sure the lift is in balance, and check for mechanical issues prior to lifting any vehicle. Additional lift malfunctions include:
- Sagging lift arms
- Safety cable failure
- Air leaks from the compressor or hoses
- The lift bounces when going up or down
- The lift will not come down
Always know your last lift service date. In fact, it is a good idea to schedule yearly lift inspections by an ALI-certified professional like Allied, Inc. If you notice issues before your next yearly inspection, contact a professional to check the lift before using it again.
Get Help From Allied, Inc.
It’s better to be safe than sorry, so always make sure you read the operator’s manual for your lift, which includes instructions on safe use, maintenance recommendations, and troubleshooting guidelines.
If you’re still unsure what type of lift you need for your shop, please contact our product specialists at Allied, Inc. We sell a wide array of automotive lifts by Rotary Lift and Forward Lift, including two-post lifts, and can ship them to shops throughout the United States. If your shop is in Michigan or northern Ohio, we can also install and inspect your lift. Please contact us today at (734) 665-4419 to talk to a product specialist or complete our online form to request a service or product quote.