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jonrjen

Need Help With Car Hauler Math Equation

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I usually tow our 2011 Jeep liberty 4 down backside of the motor home. But from time to time I would like to drag another or different non towable choice along. So I am looking at the purchase of a car hauler to pull behind the motorhome.

However, I have a math problem that I could sure use some assistance with.OK, found the car hauler I want to purchase. It would be used for general trailer use, but I also want to be able to tow a vehicle behind our motor home without making any contact between the front trailer bed and motor home when making turns of a tight nature.

Let me see if I can ask this to where it makes sense or that you can figure out what it is I am asking.

Here are the basics to the math equation:

Motor home 99" wide corner to corner at rear
Trailer is 84" wide at front of deck corner to corner.
Trailer tongue is 40" from ball hitch to front of trailer deck.
Center of rear axle to ball of trailer hitch receiver 146" (I believe this number needs to come into play when figuring the fulcrum/pivot point. On a F250 this distance would be 56")

My choices would be to take the trailer as it sits....however not sure about how the above numbers would add up to making trailer to motor home contact on a tight turn.

Have the front corners on the trailer cut diagonal at about 12" from the ends making kind of a boat tail front cut.

Extend the tongue of the trailer by 12"

Since the trailer is built as deck on wrap frame, have the deck moved back 6 to 12" (however this will change the center load point over the trailer axles, this may not be that big of a problem when loaded, but empty could result in a light tongue weight).

FWIW: The trailer is 20', 83" deck width, wood floor, dove tailed, medium duty, 2 each 5,200# axles with brakes on each, 2 5/16 bulldog hitch, 5" frame, with ramps stored under the rear of the deck, 7K drop jack.

OK back to the math, again the point is that I am looking to avoid any expensive fiberglass work from the trailer making contact with the motor home rear corner on any tight turns.

HELP, I appreciate your assistance,

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I had the same problem with my toad because it a 1/2 ton Silverado pickup. Another thing to consider is the turning radius. Without going through the math I just went to an empty parking lot, with the truck hooked up and turned a corner with my wife walking along side of the back bumper. When it got too close I straightened out. I extended the tow bar back 6 inches to get the proper clearance.

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I ordered an enclosed Haulmark trailer and had the tongue extended to close to 5 feet. Never had a problem. The real deal is to aim your eyes high forward and plan your turns. Think big- like an 18 wheeler

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With a little patience you can build a template to measure your turning radius. You need two pieces of wood in an L-shaped pattern. One board would be the length from the middle of your hitch to where the tongue meets the body of the trailer. Then measure from there to the corner of the trailer and attach another board of the same length to form your "L". Now move the board, pivoting it from the middle of your hitch until it hits your motorhome. That will be the maximum turn you can make.

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vtbigdog, on 17 Apr 2013 - 22:10, said:

With a little patience you can build a template to measure your turning radius. You need two pieces of wood in an L-shaped pattern. One board would be the length from the middle of your hitch to where the tongue meets the body of the trailer. Then measure from there to the corner of the trailer and attach another board of the same length to form your "L". Now move the board, pivoting it from the middle of your hitch until it hits your motorhome. That will be the maximum turn you can make.

With the way I did it I can turn as sharp as it will go and it doesn't hit. No guessing or calculating.

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Jonrgen,

The maximum cut angle would be very close to 45 Deg. if my math is correct and it has been awhile since I have worked out this kind of problem.

You could pull around a trailer in a large parking lot. As mentioned by DD and set up some cones or just use the lines panted in one to check your turning radius and the maximum distance / room needed to make a turn to the right. this is the tightest turn one needs to make. A left turn in most cases gives you the extra room of a left lane to make the swing.

That being said the radius required for a 20 ft. trailer is more then one 10 ft. long.

You did not give us the total length of your coach!

I know that someone posted information regarding the turning radius information on one of the threads. I just can not remember what one it was. That helps one understand the mechanics of a turn. With the distance of the hitch point from the rear axle, makes a big difference in the distance required to make a turn. Just because you reach the 45deg. point much faster between the coach and the trailer and a longer trailer tongue increases the turn angle, but increases the radius covered by the trailer.

What you are proposing is not something you would want to drive in an area with narrow streets.

Rich.

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Don't forget backing. I assume by a car hauler, you mean a trailer that will carry the second vehicle. If your set-up is capable of being backed up, remember the possibility of the corner of the trailer hitting the corner of the motor home.

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