Trailer hitch price

[5B Steve]

Just wanted to let everyone know the price for the hitch I talked about in my previous post, for any MCI, it would be  $ 200.00 plus shipping to your Zip Code.  Made out of 3/8 plate.  I have nothing to do with these, just passing the info on for thoes who might need one.

Steve 5B.....

[RJ]

Steve -

How is the hitch installed on your 5B?  I'm looking to add one to my 5C, and am curious as to how yours is mounted.

If you could take photos and send them to the email address in my profile, I'd appreciate it.

TIA,

RJ

[bevans6]

My hitch, and Steve said his is similar, is from Walker.  There is a picture on one of his web sites.  http://www.busrvparts.com/Towing%20Hitches.htm  It is pretty simple, it is two 1/2" thick steel plates that bolt to the flat plates on the rear frame that the engine rails come out to.  There is a removable frame piece behind the bumper that bolts across between those two flat plates.  The hitch is mounted between the stock removable frame piece and the bus frame plates with five 1/2" bolts on each side, and there is a stout tube welded across between them with the receiver tube in the middle, with 1/2" steel reinforcing plates.  I've towed my car hauler at around 7,000 lbs and it seemed just fine.  No reason to think that the hitch that Steve had made wouldn't be equally as good, and I like the basic design a lot.

Edit:  on my hitch, the receiver tube needs the bottom of the bumper trimmed for clearance, I presume to get the desired ground clearance to the receiver tube.  I also had to file the holes a little bit to get the bolt holes to line up with my bus frame holes.

Brian

[solodon]

I've seen a lot of discussion about stress to the engine cradle/rear frame when towing a trailer.  Would that still be a concern with this hitch??  Looks plenty strong enough, just wondering about long term usage and eventual problems.

[bevans6]

Time will tell.  I think that part of the bus frame is quite strong.  It is supported fore-aft by the engine rails, and up-down by the engine support framing.  It kind of is cantilevered out along the engine rails, and supported from above by the main bus monocoque.  I look at it this way - in a stock seated bus there would be the lavatory up there, the rear row of seating adding load, and the big AC compressor, all adding load to that part of the bus structure.  Now that's all gone and I'm adding load through much of the same frame structure.  It would seem to be a decent compromise.

Brian

[solodon]

Brian, I agree with the lack of the bathroom, a/c compressor and seated passengers reducing the weight in that area however none of that weight is like having a trailer hanging off the rear and trying to flex the frame up and down with the movement that a trailer puts on a hitch.  Seems to me it'll be OK with the hitch pictured however still a little concerned.  Hate to do something that is going to cause very costly problems later.

[bevans6]

Don, no doubt there is a degree of risk, as with everything.  I use a weight distributing hitch to reduce the torsion on the hitch receiver from tongue load, and so far so good.  A large part of the point of having the bus is to tow the trailer and if it couldn't tow the trailer I would get rid of the bus, so towing the trailer is not an option for me.  For others, they can make their own choices.  So far so good is just that,  I'll continue to inspect! 

BTW, weight is weight.  Tongue load weight obeys the laws of physics and is subject to the same force equations as any other kind of weight.  I honestly don't understand this idea that the forces developed by the tongue of a trailer are any different than the forces developed by any other kind of weight.  It is all subject to the same rules of nature.  You can draw out the force vectors and predict pretty exactly what the loads will be.

Brian

[Tikvah]

It is supported fore-aft by the engine rails, and up-down by the engine support framing.  It kind of is cantilevered out along the engine rails, and supported from above by the main bus monocoque.

I keep looking at all that support and wonder what's the problem everyone talks about.  It looks very strong.  Yes, there's a lot of weight back there, but you would think the roof would cave if the hitch was too much - seems impossible.

I have a hitch, much like the one advertised, but I just pull a car on a towbar... no weight.  But sometimes I think I'd like to.

[solodon]

Brian, I'm not trying to be argumentative here, I'm trying to wrap my mind around how the weight is applied to the bus.  It seems if the hitch is bolted to the cradle/frame and the trailer is connected even with a WD hitch that the load is applied directly to the the junction of the trailer and therefore adds stress to the frame directly.  Any weight that is in the coach is going through the monocoque body to the frame and is distributed over a much greater area.  I'll probably get this hitch as I see it as a good unit however I plan to have a suspension under the front of the trailer and a pivoting tongue so the vertical loads to the hitch are similar to that of a tow bar while the horizontal loads will be greater but more acceptable.

[bevans6]

Any load applied to a structure can be imagined as a point load - you put the load's mass at it's center of gravity.  The structure takes the load and is designed to distribute it.  Like a bridge - you have the trusses and spars and cables, and you go out and stand in the middle of the bridge.  You are a point load acting on one part of the structure, but the structure is designed to distribute that load throughout its entire construction.  Same with a bus.  In this case, there is a main body structure that comes back over the top of the engine bay and comprises the roof, the walls, the floor of the bus, and the structure that houses the radiators.  It's kind of a complicated tube frame and stressed skin monocoque and is quite strong.  You have two tube structures that act as the left and right door posts of the rear doors, and they come down and pick up the ends of the engine rails.  There are big triangular fabricated plate-like structure on each side that massively strengthens that specific part of the tube frame chassis at the rear of the bus.  This is what the hitch plates bolt to, spreading their load over the fabricated plates.  The engine rails run out from the massive structure at the front of the engine bay, and are cantilevered tube frame structures.  All of the comes together so that the load from the trailer hitch is distributed up and back throughout the entire rear structure of the bus - including the roof, the passenger floor, the walls, and the engine bay framework.

Brian

[Jon]

Every structure has its limit. MCI engineers should be able to advise what the limit is.

We know from experience that the structure on the rear of the Prevost coach will experience hidden and substantial damage if the limit is exceeded. The original engine cradle / trailer hitch design limit was 10,000 pounds, 1,000 pounds tongue weight, 8" from the rear bumper. Later and current models are now 20,000 pounds, 1,500 pounds tongue weight 6 or 8" from the rear bumper depending on the placard.

Since our coaches were designed as seated coaches and were not originally designed to carry or tow heavy weights it will not take much to damage the structure. For example some folks were putting a motorcycle lift on the rear of a Prevost. That put the CG of the added weight well past the 8" point, and the added weight was likely 1,000 pounds. The resulting damage was broken welds at the engine cradle and broken welds at the diagonal stressed members that are hidden by the outer skin and the interior walls.

The first visible signs were stress cracks along the lower portion of the rear fiberglass cap and at the rivets connecting the cap.

Just because the vehicle is a bus and its structure looks ample you become a test pilot when you start towing heavy loads, specifically those that impose large loads on the hitch.

[solodon]

Thanks to all for the enlightenment.  I think I'll get this one as it's stout for my initial towing needs (about 8000 lbs) but will add at a later date s suspension under the front to remove the vertical loading.  As good as the hitch is, it can't hurt to remove that load.

[Fredward]

Hey guys - real life example for you. Do with it as you will. (I don't know what to do with it!) I've had the 871 out of my MC-5A two times. Both times the weld at which the drivers side engine cradle attaches to the monocoque frame post was cracked. The first time, we welded a big patch in there to spread out the stress. The second time, cracked again although not as bad. I only pull a car dolly or light aluminum trailer with less than 150lbs hitch weight. We put about 6,000 miles a year on the bus.

I have an enclosed trailer I'd like use instead of pulling the car on the dolly, but don't dare hitch it up for fear of finding my 871 laying on the interstate somewhere.

-Just sayin'

Fred

[Jon]

When someone has their engine sitting in the middle of the interstate then they might understand what some of us are trying to say.

Until then some folks are just bound and determined to do what they want.

[RJ]

IMH,NEO, I think as long as I'm flat towing my VW, the only weight on the hitch is the tow bar.

If I decide to tow a trailer, be it open or enclosed, I'll spend the $$ to get a TrailerToad, even if it's a used one.  The TT takes the tongue weight, so you're back to the same hitch weight as a tow bar.

www.trailertoad.com

FWIW & HTH. . .