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Open Roads Forum  >  Fifth-Wheels

 > Proper 5th Wheel Hitch Position

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Oatman

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Posted: 02/21/19 11:18am Link  |  Quote  |  Print  |  Notify Moderator

You have two issues, leveling and rail clearance . You can adjust the pin box, adjust the hitch and adjust the height of the FW. First thing is to shim the the FW up on scrap wood to get the rail clearance right first. You have to start with the rail clearance. Mocking it up is the best thing. Don't worry about a bunch of angles and math, you aren't going to figure it out and apply X fix to it. Also consider while mocking it up that your true travel condition is loaded.

You can go about all ofit in several ways from lowering the truck to an axle flip to tire size to subframes 2 axle alignment kits and shackle position. the main thing is knowing exactly where it is and where you want to go and how you want to get it there before you buy or do anything. when you are mocking it up you will also be able to see how your stabilizers are and your step. I ended up buying I believe 30 inch stabilizers and a torklift four step.

With it mocked up you can stand back and look at it and put a level in RV and see where it's at. if you need to raise or lower the pin or raise or lower the hitch to get the rail clearance correct you then re-adjust the wood shims under the fifth wheel tires to relevel it.

When the rail clearance is correct and the rig is level you will then know how much the fifth wheel needs to be raised or truck lowered

Allworth

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Posted: 02/21/19 11:55am Link  |  Quote  |  Print  |  Notify Moderator

No matter what some will shout, the big problems caused by unequal axle loading are, at best, Urban Legend, and more likely what some leaders call "Fake News".

It is called a problem, but nobody has EVER published any kind of proof that it was the actual cause of a problem. Nobody!

If you truly understand how an equalized suspension system works it should be obvious that the first several hundred pounds of "unequal" load will cause the system to transfer weight to the other axle. That is why it is called "equalizing". Only after the suspension of the heavier loaded axle has reached the limit of travel does the weight not partially transfer.

Don't misunderstand. Equal loading is the preferred condition and is what I try to achieve with my trailer. You are not, however, causeing some kind of disaster if you are a couple of hundred pounds off.

I'm not going to start a great debate, so that is it for this thread.

Allen


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Posted: 02/21/19 04:46pm Link  |  Quote  |  Print  |  Notify Moderator

Allworth wrote:

No matter what some will shout, the big problems caused by unequal axle loading are, at best, Urban Legend, and more likely what some leaders call "Fake News".

It is called a problem, but nobody has EVER published any kind of proof that it was the actual cause of a problem. Nobody!

If you truly understand how an equalized suspension system works it should be obvious that the first several hundred pounds of "unequal" load will cause the system to transfer weight to the other axle. That is why it is called "equalizing". Only after the suspension of the heavier loaded axle has reached the limit of travel does the weight not partially transfer.

Don't misunderstand. Equal loading is the preferred condition and is what I try to achieve with my trailer. You are not, however, causeing some kind of disaster if you are a couple of hundred pounds off.

I'm not going to start a great debate, so that is it for this thread.

Allen


A trip to the scales will prove what is right!!! A nose high trailer WILL have more weight on the rear axle in most cases. A nose high trailer will tend to chuck more with some trucks.


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RudiH

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Posted: 02/21/19 08:27pm Link  |  Quote  |  Print  |  Notify Moderator

Allworth. Thank you for the explanation regarding the equalized suspension system. I'll research it some more to become more informed.

Thanks for your input everyone.

rhagfo

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Posted: 02/21/19 10:03pm Link  |  Quote  |  Print  |  Notify Moderator

RudiH wrote:

I recently bought a new 5th wheel (Crossroads Cruiser Aire - 31.5') and a new Ford 250 Super Duty truck. The truck bed is higher than that of my last truck, and I am concerned about being able to level the rig without doing some modification to the pin box. I have not been able to hitch up yet because I left for Florida for 3 months for the winter right after the purchase. Is anyone towing a 5th wheel with the truck mentioned above? Did you have to make any modifications in order to tow properly?
I would like to be prepared for what I need to do when I return home.
Thank you in advance for your time and advice!


Well did some research and based on model length it seems you have a CR27MK. Nice looking floor plan, question did you get the CRUISER HP UPGRADES? This would include 16" wheels. That is a nicely sized 5er for your TV.

As mentioned you have two numbers you need to worry about:
#1 5er overhang to bed rail clearance, this should be 6" minimum.
#2 How level will the 5er tow, or how nose high will it be.

You can calculate both, for the bed rail clearance two measurements.
#1 lay a straight edge across the bed rails at the hitch, measure the distance from the top surface of the hitch head, with it level to the bottom of the straight edge call this measurement1. Now measure the distance from the bottom surface of the 5er overhang, to the bottom of the pin box surface (the surface that the pin is on) call this measurement2. Now subtract measurment1 from measurment2 this will be the bed rail clearance.

#2 Best with 5er and TV able to hitch. If you have both at the same location, find a level spot big enough for both TV and 5er to sit on the same level plane. First hooked up. Measure at hitch pin location to top of bed rail, call this measurment-1. Now disconnect the 5er pull TV clear of the 5er and lower until it is level. Now measure from the ground to the bottom of the front overhang call this Measurment-2.
Now math time Measurment22-(Measurment11+6)= distance the 5er needs to be raised at the axles to tow level. The +6 added to Measurment11 is the distance you wish to clear the bed rails by.


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RudiH

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Posted: 02/22/19 08:09am Link  |  Quote  |  Print  |  Notify Moderator

Russ. Thank you for the information. What you have suggested, is probably the first thing I will try. I just hope that I can hitch up at all. I know that the new truck I have has higher than normal sides on the bed, besides being higher at bed-level.

Durb

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Posted: 02/22/19 10:00am Link  |  Quote  |  Print  |  Notify Moderator

Allworth wrote:

No matter what some will shout, the big problems caused by unequal axle loading are, at best, Urban Legend, and more likely what some leaders call "Fake News".

It is called a problem, but nobody has EVER published any kind of proof that it was the actual cause of a problem. Nobody!

If you truly understand how an equalized suspension system works it should be obvious that the first several hundred pounds of "unequal" load will cause the system to transfer weight to the other axle. That is why it is called "equalizing". Only after the suspension of the heavier loaded axle has reached the limit of travel does the weight not partially transfer.

Don't misunderstand. Equal loading is the preferred condition and is what I try to achieve with my trailer. You are not, however, causeing some kind of disaster if you are a couple of hundred pounds off.

Allen


Good points regarding equalized suspensions. Keep in mind that many fifth wheels do not have equalized suspension. MORryde IS equipped trailers do not have equalized axles nor do those with Dexter Torflex axles, like mine. There are more and more travel trailers being produced with torsion style axles. I can attest to the fact that my towing dynamics are far different from nose high to level. As stated, level is always best.

laknox

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Posted: 02/22/19 10:15am Link  |  Quote  |  Print  |  Notify Moderator

Not only bed rail clearance needs to be addressed, but =pinbox= clearance does, too, in some cases. How many times have we read about people having to clip the rear corners of their pin boxes to keep from hitting the =inside= of the bed rails when turning? More'n a few. You can only raise the pinbox so much before you might start having =this= issue. Something I didn't know of when I first started out and, fortunately, didn't have to deal with. Personally, I'll take 2-3" nose high rather than losing bed rail clearance.

Lyle


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RudiH

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Posted: 02/23/19 07:00am Link  |  Quote  |  Print  |  Notify Moderator

Has anyone adapted the pin box by welding (bolting) a steel plate configuration to it in order to be able to lower the trailer at the front?

RudiH

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Posted: 02/23/19 07:22am Link  |  Quote  |  Print  |  Notify Moderator

rhagfo - the unit I bought is a CR28RL

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