Incline and dips - determining clearance

[PWRmx24]

Hello. We're about to purchase a 5th wheel. We have some property where we'll stay for a while. There's a short incline on the gravel road then it levels off. I'm concerned that as we go up, the front end of the trailer might touch the bed rails or the back end drag. Hate to buy a 38'er only to get it stuck first day. Any way to do some calculations or dry run's before to know......thanks - a concerned Newbie

[valhalla360]

PWRmx24 wrote:
"It's the RATE OF CHANGE IN SLOPE over a short distance that matters."

That makes sense. Hard to pin a number on that perhaps.....one that can be measuresd and used. I guess experienced haulers just go by past experience.

That's why I initially said, you would almost have to do a survey but if you could get a buddy with a similar rig to slowly pull in, you could check it out ahead of time.

[PWRmx24]

"It's the RATE OF CHANGE IN SLOPE over a short distance that matters."

That makes sense. Hard to pin a number on that perhaps.....one that can be measuresd and used. I guess experienced haulers just go by past experience.

[valhalla360]

campigloo wrote:
I don’t know much about 5ers so this may sound stupid but here we go. Could you make something that would hold your tailgate part way open and part way closed while your crossing the dip?

Doesn't really help. The back corners of the bed are not part of the gate.

Now if you replaced the bed with a flatbed deck, that would solve the issue.

[valhalla360]

PWRmx24 wrote:
Will think about the 10 degree comment. Sounds like a 10 degree slope would be max?

The slope is not the issue. You can go up a 15 degree slope as long as the change from level to 15 degrees is gradual.

It's the RATE OF CHANGE IN SLOPE over a short distance that matters.

[campigloo]

I don’t know much about 5ers so this may sound stupid but here we go. Could you make something that would hold your tailgate part way open and part way closed while your crossing the dip?

[PWRmx24]

Will think about the 10 degree comment. Sounds like a 10 degree slope would be max?

[PWRmx24]

Thanks for the replies. I stepped it out again this morning and think it will work. But perhaps will have some 2x8s for an emergency.

[MFL]

If not a long distance, and you say the FW will be staying put for a while at this location, using several 2x8s to put under FW tires to raise it as needed, may be an option. If the second person watches for clearance, adds planking as needed to gain clearance, it will work, considering a short distance.

Jerry

[Thermoguy]

The clearance between my bed rails and truck bed is less than 6". This summer we stayed in a hay field in MT. The access to the field was less than good. On an angle, from the road dropped down quite a bit to the field. Driving in was no problem, the angle was odd, but the trailer followed just fine. On the way out, not the same at all the trailer came within about an inch of touching the truck. Thank god it didn't. I drove slow, but really wasn't prepared if it had hit.

I guess my advice is that there is no way to know until you do it. Just go slow and be prepared to stop and rethink the approach angle.

[valhalla360]

This is one of the downsides of 5ers. A travel trailer hitch can rotate 20-30degrees in any direction on the ball. A 5er, your lucky to get 10 degrees (often less) before you hit the bed rails (depends on how much clearance you have). So they aren't nearly as well suited to rough conditions.

Once hitched up, it's not hard to measure the clearance and calculate the angles available. Determining the angles you need on the driveway, it can be done but you almost need to do a full survey of the drive.

If you have a buddy with a similar rig, you could ask them to pull in (slowly) and see if it works. They can always back out if it's getting too close for comfort.

6" is the typical clearance considered desirable but if you can get it set up for more, that will be helpful (make sure the trailer is still level while towing). It may require adjusting the axles to keep the trailer level.

Possible solutions:
- A sliding hitch will help with fore & aft angle. The closer the pin is to the tailgate, the sharper the angle you can traverse.
- I'm not sure if this is something problematic but there are air ride pin boxes. While the primary intent is to smooth the ride, you could check with the manufacturer to see if you could air it up beyond normal pressure. This would lift the front of the 5er relative to the truck and give you a little more clearance. As long as it's for short distance at low speed, I don't see why it would cause damage.

[guidry]

A good rule of thumb is 6" of clearance between the truck bed rail and bottom of the trailer. I have 7" and have never had a problem. Be careful and go slow.