Heavy haul truck spec help needed

Discussion in 'Experienced Truckers' Advice' started by Northern Operator, Mar 27, 2020.

  1. Northern Operator

    Northern Operator Bobtail Member

    Mar 27, 2020
    Hi all, we have a unique situation we’re we have special built tractors that have a concrete breaker mounted on them. Every truck we have now is built in the normal axle config I.e 12k F 32R. Around 200WB. Now we are always pushing the weights with this setup, especially on the drives. We have tried pusher axles but these breaker Attachments put most of the weight back on the truck and it’s very hard to get weight transferred to the front. My question is if we went to a 18 or 20k front with 46 or even a 60k tri drive setup with say a 225 or even a bit more WB how much weight can you legally carry with that setup without ever needing a permit going into basically every state? We really haven’t been able to get a good answer from Pete salesman or even there engineers. All info is greatly appreciated!
  2. seagreg

    seagreg Light Load Member

    Oct 3, 2019
    weight can you legally carry with that setup without ever needing a permit going into basically every state (on the interstate system) is restricted by 23 CFR Part 658.17

    All of the higher limit states were grandfathered in decades ago, State Exceptions to Federal Truck Weight Limits

    Here is the Fed bridge formula,

    W = max weight
    L = distance in feet between outside axles in a group
    N = number of axels.


    States are subject to the standard Federal weight limits for Interstate highways (20,000 lbs. on a single axle, 34,000 lbs. on a tandem axle and 80,000 lbs. gross vehicle weight) unless there are State-specific grandfathered limits...of which there are multiple over 50 years time that give 37 States and DC some higher limits but are not standard enough for what you are asking.

    That is why Peterbuilt can't give you an answer, outside of 20K single, 34K tandem and 80K GCVW there isn't one.
    Farmerbob1 Thanks this.
  3. Ridgeline

    Ridgeline Road Train Member

    Dec 18, 2011
    Did you by any chance contact the company that makes the unit and ask them for someone to talk to who has done this upfitting for them?
    wis bang Thanks this.
  4. mnmover

    mnmover Road Train Member

    Apr 5, 2009
    Lichfield MN
    Have you looked at a single axle drive truck with 2 pusher axles that would allow you to air adjust the lift axles to shift weight to the steering axle. A 4 axle straight truck can gross around 50,000 lbs plus. A single drive axle can carry 20,000 lbs, add in two liftable axles depending on tire selection could be 14 to 18,000 lbs on each axle. Peterbuilt should know how to build and set up multiaxle vehicles. If not ask a Mack or KW dealer. Make sure your truck is double framed. A single axle drive should work as you drive on a concrete highway, not off road.
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