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bleedwater's avatar
bleedwater
Explorer
Oct 08, 2013

Lighten 2009 F250 to increase 5th wheel kingpin margin

My 2009 F250 Lariat Crew Cab 4x4 Deisel Superduty has a GVWR of 10,000 LBS. With 5th wheel hitch, 160 lb driver, full fuel and no other cargo in the truck, the CAT Scale reports steer axel 4920 lb, drive axel 3360 lb, gross weight = 4920 + 3360 = 8280. 10,000 - 8280 leaves 1720 lb for the fifth wheel kingpin. My 5th wheel literature states that my unloaded 5th wheel trailer weighs 9790 lb (dry kingpin of 1615; dry 5th wheel axel of 8175). I will visit the CAT scale soon with the trailer to get exact kingpin weight but the challenge is clearly to create some margin in my truck's 10,000 GVWR with trailer kingpin attached.

This is typical of many 3/4 ton pickups pulling a 5th wheel. I have run all the numbers thru safe towing calculators and I have good margin to spare everywhere except where the kingpin weight is added as truck cargo and I need to stay below 10,000 lbs.

Question for F250 owners :

a) Have you removed rear seats in your truck?
b) Have you removed tailgate? What did you do with the backup then?
c) Have you removed the standard Ford 12,000 towing receptical
d) Spare tire removal seems more drastic than I want to go

I have a set of AirLift 5000 ultimate air bags ordered to help with leveling.
e) For 5th wheel towing do you agree to "T" air feed so both are identical?

f) Within the year I will be due for some new truck tires. Currently I have LT275/65R20E Goodyear Wrangler All Terrain. Any better choices for a person who is running close to their truck weight limits?

25 Replies

  • Sounds like your front axle may be over axle rating.....at 4900-course once you add some weight to the rear that may change.....what TP is suppose to be in the front tires? What are axle wt ratings? how long is wheel base....lots of stuff to look at to determine things....you never really know what it all will be unless trailer hooked up and weight determines as by guidelines for ccat scales.....good luck......I find more pin wt is better than less as long as not overloaded....
  • I'd re-weigh that thing... sounds like a chevy...
    You sure about them weights? Not much payload for a 3/4ton?

    Yes the truck weights are real. The door sticker says as the truck is optioned it can carry 1986 lb as it rolled off the asembly line. So I, like you went to the CAT scates to see if that makes sense. Yes ... with driver, full fuel and hitch it does make sense in the math. All newer vehicles have the tire sticker in the driver's door. The cargo they say you should not exceed actually is the CVWR minus the weight of you truck as it rolled off the assembly line. Somewhqat ignore towing guides and ignore Edmonds base curb weights because they might confuse you on that point and make you think you have more payload than your options consumed. Then go weigh the truck to be sure you believe it.
    I am at the stage where I see the least margin or nearest limit is right there at the kingpin. I drove this a couple of seasons before I felt compelled to explore because the tow guidelines from Ford suggest I can tow well over 15,000 lb fifth wheels and I was way under that on flat midwest roads. A recent south west national park trip of 5,000 miles got me loaded with more cargo than prior trips and into more mounatins. I returned home exploring ways to level my load and reduce rear end sag of about two inches. I decided to begin with a fresh review of every single towing equation. Actually there are a series of equations that need to be met. Check www.fifthwheelst.com for a closer look. So
    I learned my kingpin weight is the tighest tolerance. I will load differently in the trailer, not load the truck cab area, possibly lighten the truck and add some air-lift 5000 air bags to assist in leveling.
  • Look for your RAWR (rear axle weight ratings). Most of the time it will be the sum of your rear tires ratings.
    I also follow vehicle GVWR but many use the RAWR.
  • More clearly stated ... I should have stated things like this
    b) Have you removed tailgate? What did you do with the BACKUP CAMERA then?
    c) Have you removed the standard Ford 12.5K Trailer Tow Hitch? I might consider removing it since I only need the 5th wheel hitch when I tow.
  • I'd re-weigh that thing... sounds like a chevy...;)
    You sure about them weights? Not much payload for a 3/4ton?