What is Minimum Distance Needed Between Truck Bed Rails and Fifth Wheel Trailer Overhang

Question

Question:

This relates to a GMC Canyon, 2018 crew cab with 63inch bed. My trailer has three inch lift on axle, but I only have three inches of clearance between bed sides and trailer with the trailer level. What is absolute safe minimum clearance. To get 6inch inches of clearance the hitch is 7.5inch out of plumb. And yes, Scamps use a Reese type hitch in the smaller pickups.

asked by: Barry S

1

Helpful Expert Reply:

You really need to have a minimum of 6 inches between the bed rails of a truck and the overhang of the fifth wheel/gooseneck trailer. Some say that 4 inches is adequate but if you are in a hilly area at all you'll want the 6 inches.

Typically on lifted trucks like yours this is a hard issue to handle. In most cases the only solution is to remove the lift on the truck. Sometimes you can lift the trailer but that isn't always an option.

You can do this by moving the axles from being above the leaf springs to below the leaf springs.

The diameter of your trailer axle will determine the size of the parts that you will need to order. If your axle is 3 inches diameter, the Dexter Trailer Springs Over-Under Conversion Kit, # K71-385-00, would be a great choice and if your axle is 2-3/8 inch diameter you could use the Over-Under Kit, # K71-384-00. These kits can be installed without welding but the manufacturer strongly recommends having the new spring seat tacked in place on the other side of the trailer axle.

Some refer to this process as "flipping the axles," but since axle has a slight bow to it you can't just flip them and reinstall them under the springs using the same spring seats. You have to install new spring seats on the opposite side of the axle so that it can be moved below the spring.

expert reply by: Jameson C

1

Answer 1

Increasing the tire and wheel size can increase the height of the trailer but it's usually quite minimal. Before you do anything else you should see if the pin box can be adjusted. Although you have to be careful here since This will lower…

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Answer 2

If you take a look at the linked diagram you can see the minimum recommended clearance distances between truck and trailer for 5th wheel towing. It is recommended to have at least 5-inches from the top of the bed rails to the bottom of the trailer…

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Answer 3

Choosing the right height setting for your 5th wheel hitch is a combination of a few different variables. First of all you want your towing setup to be as level as possible. With your Montana High Country 340BH level you will want to measure from the…

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Answer 4

The three most common lug stud sizes for a trailer are 1/2"-20, 9/16"-18, and 5/8"-18. In order to make sure you get the correct lug nuts you need to measure the lug studs on the trailer now as we have no way to look this up for…

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Answer 5

As a general rule of thumb, there needs to be at least 6" of clearance between the top of the truck's bed rails and the loft of the trailer in order to prevent contact. Therefore, the 7" of clearance you have now is not too much. This…

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Answer 6

I reached out to Lippert who was able confirm that your Hub 814202 only came with the 1/2"-20 wheel stud for a 1/2"-20 Lug Nut #CE11051. Unless the studs were changed or the studs/lug nuts are stripped there should not be any fitment issues…

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Answer 7

The trailer lift kit options really come down to the axle type and setup. For leaf spring axles, you can either flip the axles with a kit like part #K71-384-00 or part #K71-385-00 or you can raise the hangers/shackles with a kit like part #LC425750.…

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Answer 8

To drop the front of the pin box and thus lower the front of the fifth wheel, you'd need to RAISE the pin box, not lower it. Lowering the pin box would raise the height of the fifth wheel at the front. If you have an available set of holes at the…

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Answer 9

A 235/85R16 trailer tire such as the Karrier #AM10501 will be 31.7" in diameter and 9.3" wide while a 225/90-16 trailer tire - which is a size we do not carry - measures 31.9" in diameter and 8.9" wide. I have added a link to a…

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Answer 10

Yes, you can use the over/under conversion kit #K71-385-00 to move the axles to the tops of the leaf spring stacks. Dexter has the following note on the conversion kits: When converting from underslung to overslung, the installation of bump stops to…

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Answer 11

I can tell you how to easily determine the correct over/under conversion kit for your 2017 K-Z Sportsmen Classic 180THT, though we would not be able to verify a specific fit for any trailer. It's easy to determine the correct over/under lift kit…

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Answer 12

I do have a couple possible solutions for raising your pontoon trailer, however increasing the shackle strap size will not be your best option. A more efficient way for raising the suspension on the trailer will be to use longer hangers. Unlike…

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