New Hitch on our 68 Eagle 01!

[bevans6]

Just a FWIW on fasteners.  SAE rated bolts, which include Grade 5 and Grade 8, are not even rated in shear.  All there is for shear is a de-rating rule of thumb from the rated tension load.  They are designed for use in tension applications.  If an engineer has a shear load requirement, they design in a dowel pin, which is designed to locate parts in shear.  In that hitch application, the vertical bolts are supporting the tongue weight load only, which is minimal, maybe 500 lbs per bolt.  The larger load is the fore-aft load, which will be in shear on the bolts anyway, unless the bolts are done up to the proper torque in which case friction between the parts takes up all of the load.

Brian

[Dreamscape]

JimH (Busguy01), I appreciate your concern. What kind of bus did you have the problems with?

A little of my background. I worked on concrete block manufacturing machines for many years. They are the most vibrating and noisy machines you will ever see. If you didn't torque bolts properly, you had problems. One thing that is important is the mating surfaces. If not clean and flat, even if the proper torque was applied to the bolts, they will loosen up.

I know that's apples and oranges, but the same application applies.

Believe me, there is concern for me in this area. I don't want to see my toad or trailer pass me.

This is a new frontier for me, never towed anything with our coach, just with other vehicles. So your replies are taken seriously.

Thanks,
Paul

[bevans6]

JimH (Busguy01), I appreciate your concern. What kind of bus did you have the problems with?

A little of my background. I worked on concrete block manufacturing machines for many years. They are the most vibrating and noisy machines you will ever see. If you didn't torque bolts properly, you had problems. One thing that is important is the mating surfaces. If not clean and flat, even if the proper torque was applied to the bolts, they will loosen up.

I know that's apples and oranges, but the same application applies.


Thanks,
Paul

I would say that's apples and apples!  The exact same principles apply to any bolted joint.  Mating surfaces clean and dry, bolts installed in tight fitting holes, corrected unthreaded length on the bolt (which is one reason why SAE are poor in shear applications, you invariably end up with thread inside the joint, and the shear strength of a threaded rod is totally poor) and the correct pre-load on the bolt, which is created by stretching the bolt, and teh easy way of doing that is to torque them to the correct torque. 

FWIW AN and NAS bolts, for the aerospace industry, are designed for use in shear applications and come in length increments of 1/16" or 1/8" so that you can have a shear installation with no thread inside the joint. 

Brian

[luvrbus]

I would not worry to much about the bolts and shear a hitch is just a as good as what it is tied into, you have a hitch tied into a frame rail on a Eagle that was design for side to side torque not up down just be careful with the tongue load because a beefed up 10,000 lb hitch lb doesn't mean much.
I put some loads on my Eagle and so far no problems only thing I would have done different on Paul's hitch would be a pull strap to the bulk head he is pulling just from the cradle but it will work if his frame rails are in good shape.


good luck

[Dreamscape]

I checked my frame rails before I even considerd it. They appear to be in great shape, straight and no cracks. Not even any rusted spots!

I really don't intend to put much tongue weight on it, maybe 500# at most. I just wanted it beefy to make me feel better.

Heck, I don't even have a toad or trailer, which I want, yet. Just trying to think ahead for the day!

[luvrbus]

Paul, our van and the pickup both have 10,000lb hitches with tongue weight of 1000lbs  3 - 7/16 bolts on each side of the frame that's all and they don't look like good bolts lol and 1/4 inch plate on the sides for the bolts. 


good luck

[kyle4501]

You'll be fine as long as you keep an eye on it - sort of like the rest of the coach. You check the oil & water, the tires & lug nuts. You grease it & check the brakes & suspension. You do walk arounds when you stop. If you just add a visual inspection of the hitch, you should have plenty of warning before any catastrophic failure.

It isn't the static tongue weight that causes the unpleasant surprises & ruins an otherwise good day. It is the impact loading & momentum that the hitch has to resist. A balanced trailer & good roads are easy to plan for. It is the bad roads & shifting loads that make things interesting & test your abilities.
Dips in the road can impart awful loads on a hitch. There is a road near by that has heavy scaring on either side of a dip caused by the trailer frames after the tongue broke off - I saw it happen once. I believe a good visual inspection would have kept that trailer off the road that day.

I've gotten away with towing over 11,000# on a 7500# trailer with a 2" ball, but I'd never advise anyone else to do so. Sometimes, you "run what you brung" & keep your fingers crossed the whole time. All the while praying you don't have to do this again.   

[Chopper Scott]

One concern I would have are the 2 bolts going through the 3" channel in the rear of the hitch. If it is, and it looks to be, standard channel it will not have a thickness of 1/4" and could pull through. Cut some flat plates about 3/8 " thick that will fit between the channel side rails, mark and drill the holes and let them serve as washers. I'm not familiar with the frame work of your bus and someone like Cliff will not lead you astray.

[rdbishop]

Good looking hitch Paul,

That thing will be here when you and me are gone!!!!! Now to decide What to use for a toad. How does Becky like her new job?

Richard

[Dreamscape]

Richard, She says it's going great! At least she doesn't have to look at my ugly face during the day anymore!

Still undecided on what to do. Becky now has her mom's 04 Cad, and I have the 94 Lincoln. I'm thinking of getting rid of the Lincoln and getting a jeep wrangler and an enclosed trailer so I can have a small work shop. It will make it much easier if I had a place to tinker!

[Busted Knuckle]

Richard, She says it's going great! At least she doesn't have to look at my ugly face during the day anymore!

Still undecided on what to do. Becky now has her mom's 04 Cad, and I have the 94 Lincoln. I'm thinking of getting rid of the Lincoln and getting a jeep wrangler and an enclosed trailer so I can have a small work shop. It will make it much easier if I had a place to tinker!

\


Uh, I thought that was what a bathroom was for?

Opps never mind you said tinker not tinkle!
  BK 

[Bestekustoms]

Paul, Your Hitch Looks Great. !! I Have A Hitch On My Eagle And Your Going To Love It !!! Thats Right...LOVE IT. You Get To Haul More Junk With You On Trips !!

I Understand You Wanting To Pull A Jeep To Carry More Tools And Stuff Like That. But, Get Rid Of The Lincoln That Could Be A BIG Mistake. You Say 1994...So Thats The 4.6 Right. I Have Had A Few Of Them Hot Rod Lincolns....What A Great Car !!! I Sold The Last One Because My Wife Wanted A Black Cadillac STS. Also A Good Car But, I Still Think The Lincoln Was A Beter Dependable Ride ..IMO !! ( In My Opinion)

And Then You Said......
A little of my background. I worked on concrete block manufacturing machines for many years. They are the most vibrating and noisy machines you will ever see. If you didn't torque bolts properly, you had problems.

Heck, I Knew A Guy In Vegas Who Has A Harley That Could Beat That One..!!!  LOL !!...

Take Care

JOHN

[Dreamscape]

John, That's funny! I think I know the same guy!

I really like the 94 Lincoln, but it's a matter of needs right now. Besides, Becky has her car I can use now and then! It has just at 144,000 on it and it rides like a dream, gets about 19 mpg. I think it one of the best designs Lincoln had! IMHO