Let’s Figure Out the Weight Rating of Your Trailer

Look at that pile of heavy machinery and large power tools, not to mention water tankards and cement bags you need to bring to your next worksite. You’re listening to your axles creak, spitballing poundages in your head, and thinking about those uphills on the way to the jobsite. As a trailer hauler, you need to know the weight rating of your trailer axles.

You Sticker Stamp or Plate Can Tell You the Weight Rating

Check your axle for a sticker. Granted, time and weather, or if you bought the whole trailer used, can erode this sticker or make it illegible, but if it’s there, you should see one of two indicators. 

1. The word capacity with some number in thousands. Axles with 5,000lb capacity might read “Capacity 5,000”. 
2. The abbreviation GAWR, which means Gross Axle Weight Rating. There will be a number in the thousands next to this one, too. 

2. Measure the Axle Tube’s Diameter

If it has been a minute since geography class, the diameter of your axle tube is its thickness. The length is from tire to tire. Hold your measuring tape across the axle, parallel to the tires. You should have a measurement of a few inches. 

This chart tells you the relationship between diameter and capacity. 

Trailer Capacity	Axle Diameter Inches
1,000 to 2,200	1½ to 1¾”
3,500	2⅜”
5,200 to 7,000	3”
8,000	3 1/2”
9,000	4”
10,000	5”

Determine the Capacity by Wheel Bearings

Your wheel bearings can tell you your weight capacity! Bearings are common to specific axle sizes fairly often. For example, if you have a 3” diameter axle with an inner bearing of of 25580 and an outer bearing of 02475, you have a 7k axle. If all that is confusing, call the Trailer Parts Outlet! We are trailer parts experts, and we’re always happy to help. The bearing numbers are stamped on the bearings themselves. If they aren’t visible anymore, you will need a digital calpier to get their measurements.

Common Inner Bearings	L44649 L44643 L68149	L68149	25580	25580	25580	387A	387A 3955
Common Outer Bearings	L44649 or L44643	L44649	14125A 15123 LM67048	14125A 15123 02475	02475	25580	25580 387A 3955
Common Capacity	1,000 2,700lb Axle	3,500lb Axle	5,200lb-6,000	7,000lb Axle	8,000lb Axle	9,000lb Axle	10,000lb Axle

5. Call the Trailer Parts Outlet for Help Determining Your Axle Capacity

Some of these solutions are simple. Some aren’t. We love helping people and we know everything about trailer parts here at The Trailer Parts Outlet. Tell us what information you do have access to, and we would be happy to lend our expertise and help you figure out how much your axles can carry!