Forum Discussion

goldline's avatar
goldline
Explorer
Mar 06, 2019

Backing a 5th wheel up a Steep Driveway

I will be purchasing a HD diesel dually from one of the big 3 in addition to a 35' to 37' 5th wheel trailer. At least the desired length.

I'm sending this post to ask for feedback.

I have a 40' length cement driveway that leads directly to a side house RV parking space where I will store my 5th wheel. The driveway is sloped upward from the street to the highest point of the driveway by about 3'. The side house RV parking is flat.

In the past, I had a 23' travel trailer and was able to routinely and successfully back the trailer up the sloped driveway as long as I backed the trailer in a gradual 90 degree long sweeping turn versus backing up straight back. Backing straight caused the lower rear trailer bumper/frame to drag for a short period of about 2'.

The challenge and concern is backing a 5th wheel up the sloped driveway without:
1) Dragging the rear bottom back of the 5th wheel on the sloped driveway causing damage to both the trailer and driveway
2) Hitting and damaging a truck bed rail from the 5th wheel trailer overhang
3) Lifting trailer wheel off the ground putting pressure on the axle

I recently had a neighbor test this concern with his 2018 Ford F350 SRW backing his approximate 40' toy hauler 5th wheel. The above three point concerns happened. Though, we did not proceed up the driveway when noticing the issues began to occur. No damage occurred, though definitely would have happened if we proceeded.

My question is more of a mathematical question.

How do I figure out what length of 5th wheel I'll be able to buy that will not drag the bottom rear end of the 5th wheel and will not hit the truck bed rail? I've searched the internet with limited success. Others have posted similar questions, though no viable answers were given other than what I have mentioned in this e-mail.

There are at multiple variables involved, some that I probably haven't even thought of:
1) Most truck DRW's that I will purchase will be lower than the F350 SRW my neighbor used.
2) My neighbor's Toy Hauler at 40' is longer than I will purchase at 35'-37' or if needed smaller.
3) I realize that there needs to be at least 7" clearance between the truck bed rail and the 5th wheel overhang. Are there 5th wheel hitches/pinboxes that off greater clearance. I'm interested in 5th wheels ranging in GVWR between 16k and 20k lbs.
4) When measuring my neighbors 5th wheel bottom rear end to the rear axle, it measures 11'. Will 5th wheels with shorter measurements improve the odds of avoiding the rear trailer drag?
5) My neighbors 5th wheel has a triple axle. Will the 5th wheel I purchase have better likelihood of not dragging with double axles?
6) If appropriate, adding trailer drag wheels if the bed clearance and trailer wheel lift issues are resolved.

Thank you for any answers and input!
Mike

29 Replies

  • Different trailers will have different heights, and axle location will differ slightly with measurement to the rear bumper depending on manufacturer and floorplan. It really will be a guessing game.

    A fix I can think of is to use a tractor. Add a hitch to the 3 point of the tractor, then you can lower the nose of the trailer to clear the driveway with the bumper. Unfortunately, with a trailer that size it will require a decent sized tractor (cost) to be able to pick the pin weight, probably something in the 40hp range. An old used one could be had for a few thousand, but still a significant investment to just park a trailer.
  • Pictures and even a Google aerial shot of the driveway might help people give you better ideas.

    Bed rail clearance probably isn't going to be an issue unless the driveway to flat transition at the top is fairly abrupt. Because the pin is so far forward, you'll be lifting the trailer away from the truck on your way up the hill.

    If you can get accurate heights and/or angles of the driveway, you could probably cut shapes out of paper to help visualize the geometry. May seem childish, but much easier than doing the calculations.

    If you end up very close on clearing, approaching at a non-90 degree angle, air bags on the truck or a slider hitch might allow you just enough wiggle room to make it work.
  • If your neighbors triple axle would not work, it is unlikely that a double axle will work, unless it is much shorter. Obviously towing nose high will make the problem worse also. A DRW will be less likely to tow the FW nose high. Was your neighbors rig level, on level ground?

    Like mentioned, using planks at the appropriate time may help.

    Jerry
  • Find someone with a fw more like you are interested in even if you have to throw them $50 or $100 to do it.

    Take pictures and get some measurements. Spending a few hundred is better than making a mistake that might result in thousands for storage fees.
  • Yeah, planks to raise the rear up was my first thought also. But since the trailer see-saws on the wheels, that would lower the front of the trailer, hitting the truck rails maybe.
    Sorry, I've got no answer but to try it.
  • 4x4ord's avatar
    4x4ord
    Explorer III
    You could lay planks down on your driveway to back up on and lift your trailer at the appropriate spot. You could have a subframe built and installed to raise the trailer 3 or so inches.
  • I put wheels under my frame to keep from dragging bumper. I also pull in and back out. Put my wife in the street with a walkie. I come close to the bed rails but hasn't been a problem.
  • Try backing in at an angle from farthest corner of driveway towards where you will park it. Yes you may get a little tilt, but should clear things......just go slow. Also, make sure you have a 4-way pivoting head hitch.
  • While the geometry can be calculated, it's not simple math problem as it's a 3 dimensional problem.

    Realistically live testing like your friend tried is the best way...of course that means you would need to talk the dealer into letting you try backing it in.

    How close was your friend to getting the trailer in? If it was only off by a couple feet before it would have cleared, you might be able to do something about it but if it wasn't even close, odds are you will face the same issue even though you plan to be a bit shorter.