Tow Hitch for 4106 wanted

[RJ]

Tom - The only thing about the Crown and Gillig skoolies is that those massive frame rails end just behind the back axle - unless it's a pusher model.  The mid-ship models have a huge trunk in the back, with virtually no support other than the exterior skin.

OTOH, the Gillig Phantom transit model DOES have massive frame rails that run from bumper to bumper.

HTH, y'all. . .

Mark- I realize you already have the 4106, but maybe you should consider using one of the mid engine framed buses like the Crown or Gillig since you can use the NTC350 or even NTC400 Cummins with a Allison 740.  With the 40ft, most had tandem drive rears, and then you could use the ever so cool looking Michelin X-one super single drive tires.  The 455/55R-22.5 is equal to the 11R22.5.  The 35ft version would have the same interior space as your 4106. Look at the classified ads in this site, there is a raised roof Crown that Red Skelton used that looks really nice.  If that had been available, I might have bought that instead.  Then also with a truck framed bus like the Crown, it wouldn't be much trouble to build in 3 or 4 sliders.  Even making a roof top observation platform isn't a problem either since the Crowns roof bows were made to be roll cages.  Just a thought-probably will be shot by the GMC nuts.  Good Luck, TomC

[HighTechRedneck]

Wouldn't you know it.  My first post here and I'm jumping into what appears to be a real hot issue.

I am 3000 miles from home about to pick up a 40' 1982 RTS II while on a vacation to the Northwest.  I am meeting with a hitch shop in a few days to discuss them putting a hitch on it.  I didn't expect a htch to be such a issue and it is critical to get my other vehicle home.

I presume these same concerns would apply to this bus since it is also GMC and uses a horizontally mounted engine..  Can anyone confirm that?  Anybody have any experience (that they would be willing to share) with putting a hitch on a RTS?

I don't need it for a heavy trailer but rather to pull a 2700# toad on a 500# tow dolly.  Would these same concerns be an issue with that load?  The tow dolly is rated as 200# tongue weight but as others have said the road shock will multiply that many times over.

[RJ]

HighTech -

Your presumptions are correct.

Geoff or Pete should jump in here soon, as both have RTS coaches, and have addressed this issue with theirs. . .

Geoff?

Pete??

Your comments, please.   

[OneLapper]

TomC,  if it wasn't for the fact that I love the looks of 4106, I'd agree that another bus would serve me better.   

As soon as I get back to the office I'll post some pictures of the brackets that I want to attach a hitch frame to.  I have to finish the muffler experiece first and wait a week or so for my hand to heal.  Gave myself a pretty good cut with my favorite tool; Leatherman Ti Edition!  LOL!

Mark

[phil4501]

Ah...progress. Your posting of pictures will be much appreciated.

[RJ]

  . . . if it wasn't for the fact that I love the looks of 4106, I'd agree that another bus would serve me better.

Mark

Hey Mark - whats the VIN on your 4106?

[OneLapper]

Ah...progress. Your posting of pictures will be much appreciated.

Here we go!

[OneLapper]

Russ, the VIN is 2853.  From what I know about it it's lived it's life in New England at Kelley Bus in Torrington, CT.  Maybe someone else can find out more about it, though.

Mark

[OneLapper]

And more pictures.

[OneLapper]

Okay, this lower frame member seems to be the largest/beefyest in the bus.  This part of the frame is the rear, lower radius arm pivot that runs back to the bulkhead.  The lower engine cradle bolts through the bulkhead to this frame. 

Follow this if you can (I'm not savy enough to make a drawing and post it yet, WAIT, I'll take a picture of a drawing)!  How about reinforcing the two lower frame members (pictured here) and the upper rear radius arm pivot brakets (pictured in previous post)?  Create a square reinforcement frame and triangulate the inside of the square frame. That would be very strong.  Now we take an 4" I-beam of metal and attach it to the large frame members directly on the axle side of the bulkhead.  The I-beam and the newly constructed reinforcement "square" frame are about  three feet apart, parallel to each other.  These are the main two supports to attach a frame similiar, but heavier, than Boutiller's setup.  I'll have some engineering buddies (automotive engineers, too boot!) calculate the guage of the metal based on the max trailer weight and 1000# tongue weight.

I'll make some drawings tomorrow (time permitting, big meeting at 3pm to get ready for) and try to get pictures taken, resized and posted by the evening.

Fire away, people!  The more input, the better the product.  To a degree. LOL!

Mark

[phil4501]

I guess it is time for me to get of my @$# and figure out how to post some pictures on here too. I read up on the weight distrubution hitches and they are not even close to what I thought they were. You seem to be on the right track as far as mounting points. How do you intend to support the tail end where the hitch slides in, under the bumper? If I misunderstood your post, I am sure the drawings will clear it up. Again, I will post some pics of my present setup as soon as I figure out how.

Phil Zisakis

[OneLapper]

I will work on the drawings in the morning.  I didn't have time to work on it today.

I did, however, talk to my rocket scienctist pal and asked him a few questions.  Bobbing up and down while travelling down the road will generate about 1g of addition downward force.  So if the trailer has a tongue weight of 700# static, that will easily reach 1400# dynamic on the tow hitch frame while travelling.  Now, this does not take into effect a large, sharp jolt to the suspension such as a bridge or pothole.  This will increase the dynamic load, but it's unclear as to how much.  In the case of my trailer toting race car, the dynamic load was very high because the car is light and the suspension is very stiff.  The coach is just the oppisite.  The coach as a very high mass (thus it take more energy to upset it's intended direction and plane of travel) and the suspension is very supple (four marshmello like air bags and shocks that have very little compression dampening). 

My I-Beam idea sounds like it'll work, but it'll have to be canterlevered much more that I thought.  Example:  take a 5 foot i-beam and put a pivot underneath it at the four foot mark.  If you apply a 1000# down force to the long end of the i-beam, the force acting upward on the end of the oppisite end of the beam is 4000#.  So, the longer the canterlever, the low the mulitiplication factor.  This actually make the design of the hitch a bit more simple, thus, less expensive.  There should be enough room to make this I-Beam work.  It will, how ever, need to be "bent" to follow the upward contour of the underside of the engine to tuck up underneath the rear bumper.

I still think I'll need to use the popular weight distribution bars just to help remove some of the tongue weight.

More on this tomorrow.

Mark

[kyle4501]

Hi Guys,
My $.02 -
Onelapper, don't for get that the load on the pivot in your example would be 5000#. Your example is exactly why it is so difficult to safely & reliably pull a heavy trailer with a bus. The distance from the ball to the frame is so long that the forces are multiplied.

Another thing you experienced is fatigue failure of aluminium. Aluminium has no fatigue endurance limit like steel & will eventually crack. That is part of the reason why these busses were "over built" to start with.

Are they still overbuilt after 30+ years of use & abuse from the owners, operators, passangers, & the elements? Only regular careful close inspections of the structure will tell. After all, that is what greyhound did & that is how they determined what needed reinforcing and when & how.

Sure you can pull a heavy (10,000+ lb) trailer. The next questions are;
for how long until problems arise?
at what cost?
how much reinforcing & where?
What kind of problems to expect? - small cracks? or engine falling out?

In the design of any complex structure, the material selection always involves compromise as each has its good & bad.

You are wise to approach this carefully & thoughtfully.

Good luck

[DrivingMissLazy]

Now is the time to look at an Eagle! LOL
Richard

Hi Guys,
My $.02 -
Onelapper, don't for get that the load on the pivot in your example would be 5000#. Your example is exactly why it is so difficult to safely & reliably pull a heavy trailer with a bus. The distance from the ball to the frame is so long that the forces are multiplied.

Another thing you experienced is fatigue failure of aluminium. Aluminium has no fatigue endurance limit like steel & will eventually crack. That is part of the reason why these busses were "over built" to start with.

Are they still overbuilt after 30+ years of use & abuse from the owners, operators, passangers, & the elements? Only regular careful close inspections of the structure will tell. After all, that is what greyhound did & that is how they determined what needed reinforcing and when & how.

Sure you can pull a heavy (10,000+ lb) trailer. The next questions are;
for how long until problems arise?
at what cost?
how much reinforcing & where?
What kind of problems to expect? - small cracks? or engine falling out?

In the design of any complex structure, the material selection always involves compromise as each has its good & bad.

You are wise to approach this carefully & thoughtfully.

Good luck

[kyle4501]

RE: Now is the time to look at an Eagle! LOL   Richard

Hey Richard, Why do I want to look at more rust?

BTW (If I remember corectly) the picture I saw of a bus on the side of the road after its DD fell out in the traffic lane was an Eagle.

They ALL have issues, each with its own merits/ demerits. That's why they made so many different ones.

kyle4501