How To Determine Axle Load

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

asked by: Robert. The trailer will have a plate or sticker on it that will list the VIN number.

  1. The weight rating of the axle should be listed on that same plate or sticker.
  2. 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.
  3. 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 diameterThose suggestions would be the easiest way to find the weight capacity on your trailer axle.
  4. 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. Trailer Hubs and Drums.

For 6000 lbs Axles. 6 on 5-1/2 Inch. 16-1/2 Inch Wheel. 17-1/2 Inch Wheel. 18-1/2 Inch Wheel. more information >. Reply from 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.

State Axle Weight Limits

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# BK2-100will work perfectly. Reply from Chris R.6/24/2020.

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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? Reply from 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.

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I worry about making this assumption though as going just by axle diameter isn't always 100 percent accurate.

  1. Does the seller have any information with regards to its capacity or is there any info listed in the paperwork?
  2. Reply from George6/17/2020. @ChrisRNo info was available. A, what you see is what you get deal.
  3. There is a number on the frame.
  4. Has stout tires; 800 x 14.5 66525.
  5. Reply from Chris R.6/21/2020. @George I gotcha. I wish I could offer some clearer insight here.
  6. What are you planning on using the trailer for?

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Do you think you'd even be coming close to that estimated capacity?

Axle Load Calculations – Axle Weightand Wheelbase Configuration.

Reply from 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.

Federal Limits

Reply from 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.

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The numbers will be printed inside the bearings themselves. If you can tell me these numbers I can definitely recommend the correct replacement assembly. Reply from Rick K.5/16/2021. @ChrisRI 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 # L68149I cannot find the outer smaller bearing #Seal# 19219Length from shoulder of seal to beginning of threads 3"I have pictures if needed79423.

How axle weight limits are determined

Reply from 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-EZwhich has matching bearing measurements to what you mentioned but the seal doesn't match and we don't have one that does.

Axle Weight Calculator

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.

Maximum permitted weight limit

Manufacturers, bodybuilders, and modifiers must ensure that the axle loads are optimised for maximum legal limit when a body is fitted onto a cab chassis, or when a wheelbase is modified.

It is very important to ensure that no axle on the vehicle is over loaded the legal limits or OEM ratings. Commercial Vehicle Compliance can provide a Axle Load Calculations report including a layout drawing for the vehicle dimensions, ideal body position or wheelbase and weight charts for front and rear axles.

Axle Weight Regulations And Limits By State

This provides a blueprint for the workshop, record for the manager and a sales tool for the client. This service carried out before the modifications can save time and money, achieve maximum payload, and comply to legal limits.

Why axle weight limits exist

Request an Axle Load report for your job now. If the vehicle is in the database we can provide an Axle Load Calculations drawing for $99 Including GST, (credit card charges may apply).

Axle Type

Reports can be designed for body positions optimising maximum payload or wheelbase dimensions. This service allows for one revision or amendment to the originally supplied drawing.

#1 Tire Weight Limit

  1. Additional vehicles can be added to the database on application. If requesting a new vehicle into the database please supply Manufacturers’ Spec Sheets.
  2. In this short article, we explain the formulae for calculating axle weights, and take you through a simple example.
  3. To calculate distribution of weight on the front and rear axles of a truck, use these simple formulae:.

Frost Laws

Step 1: Determine the WheelbaseYou will find this on the vehicle specification sheet. In this example, let’s say the wheelbase of the vehicle is 208 in. You will find this on the vehicle specification sheet. In this example, let’s say the wheelbase of the vehicle is 208 in.

Axle Spacings

Step 2: Determine the weight and center of gravity of the bodyLet’s say the total weight of the body is 5000 lb, and its center of gravity is 28.2 in from the rear axle.Therefore, we can calculate the Center of Gravity from the front axle to be 208 in – 28.2 in = 179.8 in.

Maximum legal weight limit

Let’s say the total weight of the body is 5000 lb, and its center of gravity is 28.2 in from the rear axle.

Therefore, we can calculate the Center of Gravity from the front axle to be 208 in – 28.2 in = 179.8 in.

#2 Axle and Axle Group Limits

Step 3: Use the formula to calculate weight on the rear axle. The Weight on the Rear Axle is 5000 x 179.8/208 = 4322 lb. Step 4: Subtract weight on rear from total weight to find weight on front.

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This leaves the remaining weight of 5000 lb – 4322 lb = 678 lb on the front axle. In this example, we have calculated the distribution of weight of a service body over 2 axles of a 4×2 rigid truck. The principles of calculating weight distribution are the same for this configuration as for calculating distribution of payload on a truck tractor with one or more trailers.

Axle spacings and weight calculator

We have kept it simple here for purposes of demonstration. If you have a more complicated configuration, or would like to be able to use a graphical interface to calculate axle weight distribution of multiple components at once, please take 2 minutes to watch this video about our Axle Weight Calculator app, or grab a free trial here.

Let’s take an example

Quick Navigation:. In 2018 the state and local governments of the United States spent more than 187 billion dollars on highways and bridges making it the 5th largest expense. 44 percent of this funding was dedicated to maintenance, while the other 56% was dedicated to the actual construction of the roads and highways [1].

Most damage to roads and bridges is done by heavy vehicles. The reason is that as the weight of the axle goes up, the damage done to the road surface does not go up linearly, but goes up by a factor of four.

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