Determining Axle Capacity On A 3" Diameter Axle Tube

Question:

Hi There, I have 3 axles but they have 5 lugs. I dont know the weight capacity because accord to the article on the website 3 tubes mean a higher capacity like 5500 or 7000 and 5 lugs mean 3500 lb. How can I determine the weight capacity?

asked by: Devon

Expert Reply:

Hi Devon,

Axle tubes with a 3" diameter can range in capacity from 5,200lbs - 7,000lbs so it'd definitely important to make sure that you're getting the correct weight capacity components. If you look at the axle there will typically be a white sticker with some information that e can use to determine the capacity. If you have Dexter axles they'll also stamp the serial number in to the metal of the axle incase the sticker ever wears off.

If you don't have a sticker or stamped in serial number then we'll need to start looking at the hubs, bearings, and grease seals to determine what the capacity is. Hubs will typically have some kind of part number stamped into the face that we can use to look up its capacity. If not then we can look at the bearings and grease seals to see hubs they fit with a 5-lug pattern. If the part numbers on the face of the bearings/seals are worn away then you can measure the spindle and hub with a set of calipers # PTW80157 using the diagram below.

Let me know what you find and I'd be happy to keep looking for the capacity.

expert reply by: Kevin C

Spindle Measurement Guide
(click to enlarge)

Devon

3/11/2024

Hi Kevin. I took another look and found the label on the axle saying the weight. It is rated for 3500 lbs even though it is 3" it seems. Thank you for the response! I am wondering whether I can upgrade the axles without changing the hangers or if I would need new hangers?

Kevin C.

3/12/2024

@Devon Typically a 3,500lb axle is 2-3/8" in diameter but you could have a custom axle where they went a bit overboard on the sizing. As long as you match up the spring seat and hub face measurements when ordering new axles you shouldn't have an issue with the original hangers. Now would be a good time to check the hangers for any damage or broken/cracked welds though. If you need help ordering a new axle then you'll want to give our customer service team a call at 1-800-940-8924.