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Community Alumni
Feb 23, 2015

NewBe Fifth Wheel Questions

Hello



I have a 2011 F250 with 20" wheels. This came from the factory set up this way. I have not lifted it or modified it in any way.



I want to buy a fifth wheel Flagstaff 8528IKWS and am worried that the bed rail to trailer clearance is not going to reach the recommended 6 to 8 inches.



Per the dealer, the axles on the Flagstaff can not be flipped and must have a lift kit welded on to them and that I may have to replace the existing entrance steps.



Dealer also says that the underbed rails for the hitch causes the pucks to extend 3/8" to 1 inch above the top of the floor ribs making the need to place lumber and plywood into the bed to get a flat floor.



Questions

Does anybody own a 8528IKWS and F250 with 20" wheels?



What did you do to achieve the recommended bed rail to trailer clearance?



Is there a fifth wheel hitch out there that gives true flat bed floor without the need to use lumber and plywood?



What is better, under bed rails or above bed rails for the hitch?



Thanks

Steve
  • I have Reese under bed and have pucks that stick up a tad. I have a rubber mat.



    This is what it looks like after the plugs are installed

  • laknox wrote:
    A Correct Track suspension mod will give you about 2" lift. Need to be sure that the springs are in the lowest holes of the hangars; if not, move them down and install a wet bolt kit at the same time. Another option for a mild lift (2-3", max) is simply to have longer, heavy-duty, spring hangars made. The couple I've seen on here have also had cross-bracing for extra strength. Short of that, a sub-frame welded between the frame and springs is the only truly safe way to raise it. Steps aren't that expensive, so that really shouldn't be much of a factor.

    Lyle


    The fiver in question has rubber torsion axles, so a sub-frame is the only lift option. Which is really a better option anyway even for leaf springs. And I agree, steps are not a big deal.

    To the OP, Forest River may have a sub-frame type lift kit for the Rockwood/Flagstaf fivers. I had a similar unit yrs ago from another manufacturer and the lift kit was like $175. All it was, was two lengths of rectangular steel tubing and 4 flat steel plates. There is no need for cross members, the torsion axles provide that cross bracing. Any good welding shop can do the work as well. But as other posters have stated, 20 inch tires do not necessarily mean a taller truck bed and clearance may be OK.
  • Roger10378 wrote:
    Most of the 20 inch wheels are mounted with low profile tires so there is probably very little difference in diameter. Your bigger concern should be the load rating of the tires. Many of the 20 inch tires are for looks and not very high in load rating.

    I have Michelin LTX M/S2 20" OEM tires on my truck. The 20" tire is less than 1" greater diameter than the 18" due to lower profile, which means the truck sits less than 1/2" higher than if it had 18".

    But the 20" tires are rated for a hundred pounds greater load weight than the same 18" tires.
  • Most of the 20 inch wheels are mounted with low profile tires so there is probably very little difference in diameter. Your bigger concern should be the load rating of the tires. Many of the 20 inch tires are for looks and not very high in load rating.
  • To give you some perspective, my signature truck unloaded is 37-1/4" and 57-1/2" measured at the back of the bed and top of the tailgate, respectively. I have a 16k Reese hitch (nothing special) that is at its lowest setting. My signature FW rides slightly nose high (maybe 1"), and I have 5-6" above the bed rails. Perhaps this info will help you. I had a FW dealer tell me there's no way to know for sure that a particular truck/FW combo will work until they're hooked up, and I tend to believe him.
  • I have the B&W Turnover Ball and Companion FW hitch; love 'em both and use them both regularly. If your truck has the OEM underbed hitch, I'm surprised that it would stick up that far, as the whole purpose of them is to be able to leave a "clean" bed. My TO Ball base sticks up not quite to the same height as the top of the corrugations in the floor. The 2 u-bolts for the GN safety chains do stick up slightly higher than the corrugation, but that's really not an issue. A Correct Track suspension mod will give you about 2" lift. Need to be sure that the springs are in the lowest holes of the hangars; if not, move them down and install a wet bolt kit at the same time. Another option for a mild lift (2-3", max) is simply to have longer, heavy-duty, spring hangars made. The couple I've seen on here have also had cross-bracing for extra strength. Short of that, a sub-frame welded between the frame and springs is the only truly safe way to raise it. Steps aren't that expensive, so that really shouldn't be much of a factor.

    Lyle
  • I have had several trucks with rails in the bed. I always put a rubber mat in the bed, to keep things from sliding. The mat is cut out, to go around the rails, so the bed is nearly level.

    You have the truck. If the dealer has the camper, or similar FW, just do the measuring. You can tell pretty close on bed rail clearance, plus the hitch, and pin weight, will set the truck down 1-2 inches.

    Most hitches are adjustable up/down, as are the pin boxes. It may tow a little nose high, 1-2 inches not a big deal.

    Jerry
  • I have a 2011, Chevy 2500 4x4 and I had to add a 4" lift to my 2012 Jayco FW. As far as the hitch rails: I have a B&W Companion and love not having the rails in the bed. I own a auction house and have to help a lot of people with hitch rails in the bed of their trucks load and unload items into thier trucks and they really seem to be a pain to work around.
  • Can't say specifically for the Flagstaff, but I had a 2007 F350 CC LB FX4 with 20" wheels and my 5er sat fine on it with 6" bed clearance. Now have a 2012 F350 CC LB FX4 with 20" wheels and still fine. The 5er sits just a very little nose high on the '12 but not enough to be a concern.

    Had rails in the 2007. But they really were not a problem or nuisance. But the 2012 had factory hitch prep which has underbed mounts and does leave a flat bed. One is not better than the other as far as function. There are several hitch manufacturers that make the underbed mounts now so you do have a choice, B&W, Reese, and others.