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"Leveling" for Towing a 315RLTS

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  • "Leveling" for Towing a 315RLTS

    "Level" is not the right word--"parallel" is what I mean to convey. What I'm trying to show is the way I bring together the Blue Ox Weight Distribution System and the Air Bags on my '17 F-350 DRW to achieve proper weight distribution and a camper ('19 315RLTS) that is parallel to the road. (Parallel meaning the vertical distance from the front to the road is the same as the rear to the road.)

    Click image for larger version

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    Easier to show than try to explain. Don't expect a super-high quality video, but hopefully it's good enough to convey what I do and how I did it. This is one of my longer videos at almost 6 minutes long.

    Any questions, fire away.



    P.S. Sorry 'bout the stuff in way--didn't clean up prior to taking pics/video.
    Forum moderators are not GD employees--we are volunteers and owners presumably just like yourself. Unless specifically mentioned otherwise, we have nothing to gain should you choose to purchase a product or engage a service we discuss on this forum.

    2017 Ford F-350 DRW, '19 315RLTSPlus

  • #2
    Question: When you changed air pressure in the bags wouldn't that also change the pressure on the WD bars, which would change the amount of weight returned to the front axle?
    RVing since 1964 and still learning

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    • #3
      Originally posted by bob/olallawa View Post
      Question: When you changed air pressure in the bags wouldn't that also change the pressure on the WD bars, which would change the amount of weight returned to the front axle?
      Great question! Best answered by an engineer--check out this video by Fastway Corporation. (Spoiler--the answer is "no". All the air bags do is level the truck, they don't move weight.)

      Forum moderators are not GD employees--we are volunteers and owners presumably just like yourself. Unless specifically mentioned otherwise, we have nothing to gain should you choose to purchase a product or engage a service we discuss on this forum.

      2017 Ford F-350 DRW, '19 315RLTSPlus

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      • #4
        Originally posted by bob/olallawa View Post
        Question: When you changed air pressure in the bags wouldn't that also change the pressure on the WD bars, which would change the amount of weight returned to the front axle?
        Bob--I thought about this some more. One thing I've never tested is how much, if any, inflating the air bags affect the WD settings. That would be an interesting test.

        From what I've learned previously from various sources the most important consideration is tongue weight, then weight on the truck's front tires, then leveling the camper, then the truck. I don't know that I can defend that with sources, it's just what I've ab_sorbed over time.

        Feel free to chime in if you think differently. I don't claim any special expertise other than what Darrell Waltrip would call "'xperience". (Only NASCAR fans will get that reference...)

        -Howard
        Forum moderators are not GD employees--we are volunteers and owners presumably just like yourself. Unless specifically mentioned otherwise, we have nothing to gain should you choose to purchase a product or engage a service we discuss on this forum.

        2017 Ford F-350 DRW, '19 315RLTSPlus

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        • #5
          My question was more about setting the WD bars first, and then changing the height of the trailer ball with the air bags, wouldn't that change the amount of tension on the hitch bars. I don't have air bags now so the ball height has to be changed on the hitch head. I don't have the trailer set exactly the same at each end, it is a bit lower in front. Is it the same each time I hook up, well almost.
          RVing since 1964 and still learning

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          • #6
            Originally posted by bob/olallawa View Post
            My question was more about setting the WD bars first, and then changing the height of the trailer ball with the air bags, wouldn't that change the amount of tension on the hitch bars. I don't have air bags now so the ball height has to be changed on the hitch head. I don't have the trailer set exactly the same at each end, it is a bit lower in front. Is it the same each time I hook up, well almost.

            I honestly don't know if it will make a difference.

            According to the Airlift we**ite (the manufacturer of the bags I have on my truck):

            Start by selecting the correct distribution bars.

            The bars must be rated for the tongue weight of the trailer (i.e., 500-pound bars for a 500-pound tongue weight). With the vehicle unloaded, take reference measurements at the front and back of the vehicle to the ground. Then connect the trailer and start loading the bars one chain link at a time, keeping the links equal on both sides. As the load on the bars increase, the rear of the vehicle will come up and the front will come down. When the front and rear of the vehicle are as close to the reference measurement as you can get (within ½” at the front), the bars are tensioned correctly.

            What's interesting is that I can't accomplish 1/2" at the front with the Blue Ox bars. It's close, though at 5/8" difference. (31" unloaded to 31 5/8" w/trailer and WDH set, using the same reference point.)

            When the bars cannot be adjusted tightly enough to achieve similar or identical vehicle-height reduction, add air to the air springs to bring the vehicle back to the correct height and balance.

            When adding cargo to the vehicle or trailer, do not compensate for inadequate suspension by using higher rated bars, or readjusting the bars, as this will cause for an unbalanced vehicle. Use additional air pressure in your air springs to bring the vehicle back to the correct height.

            Fine tuning vehicle stability can be accomplished by an adjustment to the air pressure in 5 PSI increments until the desired “feel” is achieved. Adding air may require readjustment of the bars.


            That last sentence--Adding air may require readjustment of the bars. Not sure what they mean by "may require readjustment". So to your question, "wouldn't that change the amount of tension on the hitch bars?" the answer appears to be "it might".

            Now I'm going to have to test my configuration again. I've never weighed it after adjusting air pressure. I'll definitely follow up and let you know what I find.
            Last edited by howson; 12-20-2019, 08:24 AM.
            Forum moderators are not GD employees--we are volunteers and owners presumably just like yourself. Unless specifically mentioned otherwise, we have nothing to gain should you choose to purchase a product or engage a service we discuss on this forum.

            2017 Ford F-350 DRW, '19 315RLTSPlus

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            • #7
              I think the weight change would be very minimal , a few pounds maybe. When you add air to the bags to raise the rear truck height to level you will also be raising the trailer hitch height. If this is only raised to a level position then all should stay basically the same. If you were to add a lot of air , thus raising the hitch height above level , or not enough air leaving the height below level , then this would change the pitch angle of the weight distribution bars creating a difference in the load shifting that you would require. Using the ball as the fulcrum the distance to the connection points , the strap tek and the hitch mounting to the truck , is so short the changes would be negligible.

              Brian

              PS. Pretty early in the morning for such an explanation but I may have gotten it right.
              Brian & Michelle
              2018 Reflection 29RS
              2022 Chevy 3500HD

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              • #8
                Originally posted by bob/olallawa View Post
                My question was more about setting the WD bars first, and then changing the height of the trailer ball with the air bags, wouldn't that change the amount of tension on the hitch bars. I don't have air bags now so the ball height has to be changed on the hitch head. I don't have the trailer set exactly the same at each end, it is a bit lower in front. Is it the same each time I hook up, well almost.
                Yes Bob, you are correct. Much like when you use the tongue jack to raise the TT to reduce pressure on the spring bars to hitch/unhitch, raising the rear of the truck with air bags after the spring bars have been set will reduce the pressure on the system thereby reducing the weight transfer. Air bags can be used with WDH systems, but can also be self defeating if done wrong.

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                • #9
                  BLUF: Air bags, on my setup, did not change axle weights (no weight distribution).

                  THE DETAILS
                  On the way home today I stopped at a Love's for diesel and afterwards ran my rig across their CAT scale in various configurations.

                  The baseline steer and drive weights were derived by weighing the truck without the trailer.

                  I then hooked up the trailer in its normal configuration: Strapteks engaged at the known setting (derived from previous links on the Blue Ox's chains) and set the Airlift bags at 20psi (normal setting). The steer axle was -240 lbs from the baseline. Changing the air bags to 5 psi made no difference*--the weights on the steer, drive, and trailer axles were the same.

                  I then ran the truck and trailer across without the Blue Ox bars (no WD) and 20 psi in the airbags. There was a -640 lbs difference on the steer axle from the baseline. Still without the Blue Ox bars I aired up the bags to 100psi (max) and ran my rig across the scales again. There was no difference--steer, drive, and trailer axles all measured exactly the same weights as when there was 20 psi in the bags.

                  So to bob/olallawa's original question: per Airlift's website and what I've confirmed first-hand, the correct sequence is weight-distribution bars first then air bags to level as required. The weights recorded on the CAT scale show the airbags make no difference on the weight distributed by the Blue Ox bars.

                  *The DW wasn't in the truck for the second weigh, so the actual weight slips show a slight difference but that is due to her not being in the truck.
                  Forum moderators are not GD employees--we are volunteers and owners presumably just like yourself. Unless specifically mentioned otherwise, we have nothing to gain should you choose to purchase a product or engage a service we discuss on this forum.

                  2017 Ford F-350 DRW, '19 315RLTSPlus

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                  • #10
                    howson

                    Question
                    You still seem to be nose high on the truck. Would it be better to lower your hitch head height to lower your truck nose (you have a drop bar style) and with everything the same and level up the truck? Just curious.
                    The reason I ask is way back when I had a TT that's the way the dealer had me set it up. I had a 77 high boy F250 and used an Equlizer set up with a 6" drop bar. They set the bars based on measured tongue weight and then measured and dropped the hitch head height to keep both the truck and trailer parallel. They marked the chain link for proper set up. They also showed me a tricke on how to make cranking up the bars easier - crank up the trailer when connected to the truck, then cinch up the bars (had the old style lever up type where you used a bar to set them in place), then lower everything back down. Just thinking - Keith
                    2018 Reflection 150 Series 220RK 5th whee, Star White 2022 F350 King Ranch CC Long bed (HAL) (CCC 4062lbs), B&W 25K OEM Companion,. SteadyFast system, Trailer reverse lights, rear receiver spare tire holder, storage tube, sumo springs, Victron MultiPlus 12/120/3000, Solar, Custom 6K axles upgrade, and other modifications.

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                    • #11
                      Yoda ,
                      I can't find the reference, but someone recently said to "check your Ford owner's manual--the front should be halfway between the starting and end point" or something to that effect. I wish I could credit them, 'cause it drove me to dive into my Ford manual to look.

                      Much to my chagrin (I hadn't read it before) there's a procedure in the Ford owner's manual for "leveling" your truck when towing a trailer! Luckily for me (insert "even a blind squirrel can find a nut" joke here) my measurements are nearly perfect.

                      Looking back at the video, H1 is 31" H2 is 32". Once I'm done the measurement is 31 9/16". The right value is 1/2 the difference of the two measurements. I can live with it being "off" by 1/16".

                      Click image for larger version

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                      Regarding the appearance of the truck, even when 100% unloaded it looks nose high. Always has looked that way.

                      At the end of the day all of these measurements are fine, but how does it feel? The seat-of-your-pants and feedback through the steering wheel tells me the truck is "right". Braking power is solid, front is planted with no squirrellyness. (I'm sure the engineers here are rolling their eyes at this point.)

                      There really is a lot of fantastic information in the manual for towing. I guess I should read all of it.
                      Forum moderators are not GD employees--we are volunteers and owners presumably just like yourself. Unless specifically mentioned otherwise, we have nothing to gain should you choose to purchase a product or engage a service we discuss on this forum.

                      2017 Ford F-350 DRW, '19 315RLTSPlus

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                      • #12
                        "(I'm sure the engineers here are rolling their eyes at this point.)"

                        The engineer here stands corrected. My 04 manual is very limited on towing information. It amazing how the science has changed, and the vehicles with it.

                        Thanks for taking the time to educate me. I better rest now as all this fried another brain cell and I don't have many left - like the hairs on my head.

                        Off to transplant my garden seedlings into bigger pots.

                        Thanks again
                        Keith
                        2018 Reflection 150 Series 220RK 5th whee, Star White 2022 F350 King Ranch CC Long bed (HAL) (CCC 4062lbs), B&W 25K OEM Companion,. SteadyFast system, Trailer reverse lights, rear receiver spare tire holder, storage tube, sumo springs, Victron MultiPlus 12/120/3000, Solar, Custom 6K axles upgrade, and other modifications.

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