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Author Topic: 5th wheel RV towed by semi tractor? possible?  (Read 4659 times)

nash0098

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5th wheel RV towed by semi tractor? possible?
« on: August 08, 2012, 10:16:26 PM »
I bought my first 5th wheel RV, and I am still in search of a suitable truck for my RV. However, the RV need to be towed from its current location. My brother has a class 1 license and a Freightliner Cascadia semi-tractor, he said we would do it when he get back, but he wasn't sure the 5th wheel RV is suitable for towing. His main concerns his the pin size, height, and brakes and turning lights connector. Anybody done this before? Any comments will be appreciated. Thanks (newbie  :D)

Lou Schneider

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Re: 5th wheel RV towed by semi tractor? possible?
« Reply #1 on: August 09, 2012, 01:22:54 AM »
The 5th wheel pin will mate to the commercial tractor's 5th wheel - the pin is identical to the commercial version.   The height may be a little off, but as long as you aren't in danger of dragging the trailer's  landing gear it should work.  Be careful of the 5th wheel placement - if it's a slider your brother will want to move it all the way to the rear to avoid having the back of the tractor hit the front of the trailer.

How long is the tow?  One problem is you can get metal fatigue in the 5th wheel's frame on a lengthy tow.  Even if it's air sprung tractor, the 5th wheel saddle on a commercial tractor rides rougher than one in a pickup truck and the tractor is a lot heavier, so bumps and jolts send a lot more energy into the trailer frame.  It's not an issue for a short, slow tow, but can be a problem on a long trip.  People who convert Class 7 tractors to tow 5th wheels almost always replace the commercial 5th wheel platform with an air ride hitch because of this.

The lights use a different connector - the standard RV connector has 7 flat pins while the commercial truck connector has 6 round pins.  Either replace the trailer connector or make an adapter.

The 7th pin is for the electric brakes.   You'll need an electronic controller like you'll put into your pickup truck to activate them - they won't mate to the tractor's air brakes.

You can take the 7th pin, the electric brake line, into the cab and temporarily mount a controller for the electric brakes. Or go without trailer brakes.  It's not exactly kosher but the tractor brakes by themselves should be able to stop the combination reasonably well.
« Last Edit: August 09, 2012, 01:33:00 AM by Lou Schneider »

nash0098

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Re: 5th wheel RV towed by semi tractor? possible?
« Reply #2 on: August 09, 2012, 04:37:26 AM »
This is a short tow within city limits, so metal fatigue would not be a problem. I would think a semi would have plenty of brakes power to covered both. The only remaining issue is the brake and turn signal lights connector, I wouldn't even know where to start to make an adapter .... do they even sell them? If worse come, then we'll tow it during the day with me following behind. 
« Last Edit: August 09, 2012, 04:54:13 AM by nash0098 »

winnie32v

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  • 2001 Winnebago Adventurer 32V, 2000 Jeep Wrangler
Re: 5th wheel RV towed by semi tractor? possible?
« Reply #3 on: August 09, 2012, 05:20:36 AM »
This is a short tow within city limits, so metal fatigue would not be a problem. I would think a semi would have plenty of brakes power to covered both. The only remaining issue is the brake and turn signal lights connector, I wouldn't even know where to start to make an adapter .... do they even sell them? If worse come, then we'll tow it during the day with me following behind.

This may be what you are looking for:

http://www.ebay.com/sch/i.html?_trksid=p3984.m570.l1313&_nkw=6+pin+to+7+pin+adapter&_sacat=0

Scroll down the page until you see some of the adapterd.
I'm not sure which way the male/female pins need to go, but you can search further & find them.

Also, most auto parts stores will carry a full line of these OR a RV shop, also.

Let us know how you make out.
2001 Winnebago Adventurer 32V,
30a Shore Line
Ford F-53 Chassis, V-10
2000 Jeep Wrangler Sport
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