How To Determine the Weight Capacity For a Trailer Axle

Question

Question:

How can I determine the weight rating for the axle on my heavy duty in appearance utility trailer?

asked by: Robert

0

Expert Reply:

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 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 - 1-3/4 inch diameter
- 3,500-lb Axles: 2-3/8 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

Those suggestions would be the easiest way to find the weight capacity on your trailer axle. 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. With this information we could narrow it down to what size axle you have on your trailer.

I am sending a link to a FAQ page that has information on trailer suspensions.

expert reply by: Jeff D

0

Matt

7/26/2020

I am looking for replacement axle bearings for a 2011 rockwood roo 19 foot. i measured the spindles: inner bearing Spindle diameter: 1.4170 inch outer bearing spindle diameter: 1.0625 what is the bearing kit to buy and what is the weight rating of the axle. its a torsion axle. thank you

Reply

Chris R.

7/30/2020

The outer bearing measurement you took on the spindle matches up to the L44649 bearing, but we don't quite have a match for that inner bearing dimension. I recommend verifying that measurement - if you get something closer to 1.378", then you have the very common 3,500 pound axle setup. For a replacement bearing kit part # BK2-100 will work perfectly.

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Rick S.

6/22/2020

Hello I purchased a trailer that does not have a tag on it to identify the capacity. The axle is 1.75" square tubing and the bearing shaft is 1.0" diameter. Your thoughts on the capacity?

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Chris R.

6/24/2020

I really wish I could offer some insight here but it's really hard to even guess at a capacity based on those dimensions. Is there any way to get in touch with the trailer manufacturer or seller?

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George

6/13/2020

Bought used trailer. No stickers or plate with info. 6 x 12 utility trailer, double axels 3” diameter. Breaks on one axel. By your estimated load rating of 6k to 7200#. Is that total or per axel? Thanks

Reply

Chris R.

6/17/2020

A 3" diameter axle typically has a higher 6,000 pound to 7,200 pound rating - this would be PER axle, so a total capacity of of 12K to 14.4K on your trailer. I worry about making this assumption though as going just by axle diameter isn't always 100 percent accurate. Does the seller have any information with regards to its capacity or is there any info listed in the paperwork?

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George

6/17/2020

@ChrisR No info was available. A, what you see is what you get deal. There is a number on the frame. Has stout tires; 800 x 14.5

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Chris R.

6/21/2020

@George I gotcha. I wish I could offer some clearer insight here. What are you planning on using the trailer for? Do you think you'd even be coming close to that estimated capacity?

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See All (4) Replies to George ∨

Mike

6/1/2020

How about rectangle shaped axles? Any measurements/ratings for those?

Reply

Chris R.

6/4/2020

Square/rectangle axles are harder to distinguish in terms of weight capacity. Your best option will be to simply look for the main axle tag that actually lists this information. If possible, you can also contact the trailer manufacturer with the VIN and they should be able to help you out.

Reply

Kevin O.

4/23/2020

My question is Im looking to buy ce smith trailer hub kit , i have a 2006 tracker trail star trailer for my tracker boat which is a pt 175 Im trying to figure out which axle load to get? Any recommendations?

Reply

Chris R.

4/24/2020

The axle capacity should hopefully be listed with a tag/sticker on the axle itself. Along with the proper rating, it's also important to check the inner and outer bearing numbers used on your existing hub to ensure the replacement will fit. The numbers will be printed inside the bearings themselves. If you can tell me these numbers I can definitely recommend the correct replacement assembly.

Helpful Links

faq-popular-wheel-bearings.aspx

Reply

Rick K.

5/16/2021

@ChrisR I been given an old boat trailer which has old 5 star looking hub/wheel assemble and looking to switch to the newer trailer hub style tires. Just wondering what hub assembly I would need. Axle is 3" Seal Diam - 1.93" Inner Bearing - 1.38" Outer Bearing - 1.25" Old inner bearing # L68149 I cannot find the outer smaller bearing # Seal# 19219 Length from shoulder of seal to beginning of threads 3" I have pictures if needed

Reply

Jon G.

5/17/2021

@RickK Are you talking about a design like the part # 8-174-5UC3? We have the hub and drum # 8-407-5UC3-EZ which has matching bearing measurements to what you mentioned but the seal doesn't match and we don't have one that does. The other thing is that this has a 6 on 5-1/2" bolt pattern as opposed to a 5 bolt pattern. If your boat trailer is old enough you might need to swap out your axle(s) so that you can use hub and drums that are current.

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Answer 1

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…

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Answer 2

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 3

We can help but we don't have wheel cylinders for the brake assemblies you have. Best solution would be all new assemblies like the part #AKUBRK-35-D which are 10 inch assemblies for a 3,500 lb axle. If you had a 5k axles the assemblies would be…

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Answer 4

Yes, there is a measurement you can take to determine what size brakes you need and if they will fit your existing drums. You will want to measure the diameter of your drums. I have included a diagram detailing the dimensions you will need to find.…

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Answer 5

To determine the size of the hub assembly you need to purchase you have to determine which bearings are in the old assembly. If the old assembly has L44649 inner bearings, you would use the hub you chose #8-258-5UC1. If the inner bearings are marked…

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Answer 6

The difference between an load range C and load range D tire in the same size is the capacity and psi rating. The two tires will still have the same dimensions and fit on the same wheel. The D rated tire has a higher capacity. For a ST175/80D13 like…

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Answer 7

Thank you for the photo and dimensions of your 368 equalizer! You can upgrade your leaf springs from 4K to 6K but just keep in mind that it will make the ride quality of your trailer a bit more stiff and the springs need to have the same length as…

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Answer 8

I recommend getting the correct parts for the axle that you have and not trying to use the parts in the Over-Under Conversion Kit #K71-384-00. The correct Spring Seat #TRSS175 will need to be welded onto your new axle. This will allow you to mount…

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Answer 9

Bearing 30205 is not a common type but can be found on trailer kits from Haul Master and other bargain brands. We do not have this item nor a compatible replacement so your options are to go through the manufacturer for replacement parts (that is, if…

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Answer 10

Shoreliner made the Highlander Boat Trailers and they went out of business several years ago so the VIN cannot be used to determine the axle capacity. However, if the gross vehicle weight rating (GVWR) of your trailer is only 2,120 lbs then it would…

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Answer 11

All of that is not necessary. All you have to do is lock out the surge coupler so it cannot move in and out or disconnect the brake lines. By removing the old coupler you would have to remove the brake lines any way. A surge coupler can still be used…

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Answer 12

A BT8 spindle would have a diameter of .99 of an inch where the bearings would both install and would have a diameter of 1.24 where the great seal would ride. That would require a hub part #AKIHUB-440-2-1K for an idler hub. A BTR spindle would have…

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How To Determine the Weight Capacity For a Trailer Axle

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