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  1. #1
    Left The Driveway
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    What determines Ford RAWR

    Ford rates their F350 rear axles from 6780 (mine) to 7280. How do they arrive at these numbers? Do they build all axles at the highest rating and then derate for which tire weight rating is installed? That would be my opinion. Or do they build different axle weights for different tires. I think not. Just wondering.
    2019 F-350 PSD CCSB
    2019 367bhs

  2. #2
    Site Sponsor
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    Apr 2017
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    Fort Collins, Colorado
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    Quote Originally Posted by jd0850 View Post
    Ford rates their F350 rear axles from 6780 (mine) to 7280. How do they arrive at these numbers? Do they build all axles at the highest rating and then derate for which tire weight rating is installed? That would be my opinion. Or do they build different axle weights for different tires. I think not. Just wondering.
    RAWR is the least of the axle weight rating, tires, wheels, springs, shackles, chassis, etc. The tires and springs are probably the limiting factors. It is not the rear axle itself. The Dana M275 used in current F350 SRW and some F250 is rated much higher than tires or springs. Look at the tire load ratings. For my truck (see sig), the 18" AT factory tires are rated at 3,640# (SRW). 2x3,640 is 7,280#. My RAWR (per the door sticker) is 7,230#. So 50# less than the tires.

    Chris
    Last edited by CoChris; 10-17-2019 at 09:22 AM.
    Chris & Karen
    Fort Collins, CO
    2017 F-350 SRW 6.7 Lariat Value CC LB 4x4
    2018 Solitude 310GK - Sold 7/2023

  3. #3
    Left The Driveway
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    Thanks for your reply. I failed to mention the tires are rated at 6830# with the same 50# over the rear axle rawr 6780#. Payload is a major factor but rawr is even more important and when I seen the payload sticker (3729#) I thought no problema. NOT. My fault was not looking at the axle sticker and assuming it was 7200# as in my old 2016. I just recently cat scaled my setup (367bhs) and with some added estimated weights ( DW & dog at 175# in truck & 200# mostly in loft & pantry of trailer) we should be at least 350# below both axle weight and GVW. I guess what I am asking is for assurance that we should be okay. My old setup (F-350 gasser & 303) was no problem with the weight ratings but it did keep you busy in regards to the tranny. I"m almost afraid of falling asleep with my current setup.

    Joe
    2019 F-350 PSD CCSB
    2019 367bhs

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