How to Determine Weight Capacity of Trailer Axle

Question

Question:

I know I have a 4 leaf spring on my utility trailer. Is there a way to find out which load capacity my axle is? I snapped the spring on my last trip. I have yet to remove it was trying to understand what I should be looking for before talking it apart. Thank you for any help.

asked by: Cecillia L

0

Expert Reply:

To find the load capacity for your axle you should look on the trailer VIN plate or sticker that lists the VIN number. The weight rating of the axle should be listed on that same plate or sticker. Also, the axle could have a tag or plate on it that will list the weight capacity.

You can also tell the weight capacity of the axle by measuring the diameter of the axle. Here is a list that will show the axle weight capacity based on the axle diameter:

Typical Axle Diameters Based on Axle Capacity:
- 1,000-lb - 2,000-lb Axles: 1-1/2 inch diameter - 1-3/4 inch diameter - 2-3/8 inch diameter
- 3,500-lb Axles: 2-3/8 inch diameter - 3 inch diameter
- 6,000-lb - 7,200-lb Axles: 3 inch diameter
- 8,000-lb Axles: 3-1/2 inch diameter
- 9,000-lb Axles: 4 inch diameter
- 10,000-lb Or more axles: 5 inch diameter

If you cannot determine the weight capacity using the above suggestions the next step would be to measure bolt pattern on the hub, size of brakes, and bearing part numbers, to narrow down the capacity of your axle.

The more information you can provide the better we can find you a solution.

expert reply by: Chris O

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John

7/3/2020

The above axle diameter don't include 5200lb axles?

Reply

Chris R.

7/8/2020

A 5,200 pound axle likely has a 3" diameter, although it's good to keep in mind that diameter alone isn't the best way to determine its rating. You'll want to go by the info sticker/tag on the axle itself or by checking with the trailer manufacturer if there isn't one.

Reply

Steve

10/1/2020

@ChrisR Need some information on a square tube axle w/12 brakes. The seller I bought them from had acquired them by themselves and had no info regarding their capacity or what they came off of. Specs" 2" square tube, appear to be .250 or thicker tube, and springs were over axle. 5 bolt backing brake backing plate with 12" brakes and 5 on 5.25 lug bolt pattern Outer bearing number is LM67048(Koyo brand) Using the spindle diagram featured in other answers, the measurements for mine are A-1.753" B/C Section-tapers from 1.64" to 1.435" and is " in lentgh D-1.248" E-0.982" F-1.23" Info needed, is What are your bearing replacement numbers? What is the capacity range? Then based on their capacity range, could they be used with a trailer that has 83" hub face to hub face axles w/65.5" center to center spring perch, and these axles are 90" hub face to hub face. I understand that there is a limit on how far the spring perches cam be from the hub face, is the 65.5" of the current frame within the safe range, and if not, could I reinforce the outer ends, to negate the stress/force applied to the bearings due to the narrower perches? Thanks

Reply

Jon G.

10/2/2020

@Steve We definitely have the replacement bearing # LM67048 that you need, but I'm having trouble finding anything that matches the dimensions you recorded for the B/C measurements. Did you remove that bearing as well so that we have a part number? Trailer 12" brakes usually fall in the 5.2K - 7K range for the axle but I would confirm this on your end by looking on the axle itself for a plate that says what the weight capacity is. This can generally be found in the middle of the axle. Spring seats can be cut off and then new ones welded on to accommodate differences in trailer designs but this axle that you're talking about is pretty different than the ones that you're currently using. I recommend going with an axle that has the same hub face measurement and then you can adjust the spring seats a little if needed.

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See All (5) Replies to John ∨

Answer 1

The trailer will have a plate or sticker on it that will list the VIN number. The weight rating of the axle should be listed on that same plate or sticker. Also, the axle could have a tag or plate on it that will list the weight capacity. You can…

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Answer 2

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Answer 3

Often an axle's weight rating will appear on a sticker or plate on the axle beam itself, or sometimes the trailer's main identification sticker will include axle ratings. This is helpful unless of course the axles have been replaced during…

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Answer 4

I do have a few easier options for you to determine the weight capacity of an axle other than using the bolt pattern or the number of lug nuts. The problem with using the bolt pattern to tell the axle capacity is that an axle may have the a bolt…

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Answer 5

You need to do a little more checking to be sure but I think we have what you need. Check your bearing numbers. If you have #L68149 for your inner and #L44649 for your outer then switching to a 5 on 4-1/2 bolt pattern is no problem at all. If your…

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Answer 6

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Answer 7

The 2x2 inch square axle is likely 3,500 lbs or less capacity. I would need more spindle dimensions or bearing numbers to assist. If you pull a hub and measure at the spindle where the bearings and seal ride using the digital caliper like #PTW80157 I…

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Answer 8

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Answer 9

To verify the correct bearing kit for your 2006 Snowbear utility trailer you will need to measure your spindle diameter. The Bearing Kit #BK1-100 fits a straight spindle that is 1" diameter on the bearing surface. We also have the Bearing Kit…

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Answer 10

I definitely understand how safety chain capacities and determining exactly what chain rating you need for your trailer can be a bit confusing. To keep it as simple as possible, safety chain requirements state that the breaking strength of EACH…

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Answer 11

For all of our springs we list the unloaded length measured center eye to center eye straight across. Leaf springs can extend up to 1" when flexed. If you are looking to replace old leaf springs, you will want to jack up the trailer so that the…

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Answer 12

Assuming the 25-1/4" measurement you got for the leaf springs on your 2018 Forest River Cherokee Grey Wolf 29TE was with the axle off the ground and no weight on the springs then the correct replacement spring is going to be the 4-Leaf…

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How to Determine Weight Capacity of Trailer Axle

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