******TOWBALLS CAN BREAK******

[MRFJ55]

G'DAY V-C'ERS , The other day i was driving along the highway and noticed a caravan being towed by a new Falconie thingy jackknived on the side of the road outside a motel. An old couple were just standing there scratching their head what to do next . (starting to sound like a joke , hey . )I't turns out they had gotten a flat on the van the night before ,at speed , and were forced to stay the night . When turning out of the motel driveway the next morning , and luckily at low speed , the tow ball snapped , sending the van's A-frame into the tar ! The ball had sheared off were the thread and ball meet ! I would say the troubles the night before had fatigued the metal , and the cool morning air made the metal brittle and weak . Anyway we sourced a new ball and it took 5 guys to lift the van out of the tar and re-hitch . The old couple couldn't believe the speedy help they had received , as we got them going again within 1 hour . I know there is a warning there somewhere , but how would you know that this was about to happen ? Really , i suppose we cant blame the falcon , CAN WE !!! KIND REGARDS , MAURIE . "

[Roehm3108]

It would be interesting to know if the towball shaft was a true fit in the gooseneck, or whether it was slightly undersized. Another possibility could be that the towball wasn't bolted on tight enough, or worked its way loose over time. Did you have a chance to check whether the thread of the shaft was mutilated - that's generally a good sign. Some people think their towball is on tight, if they can't rattle it by hand. Others won't use a stillson wrench to hold the ball tight whilst tightening the nut.
In this case, we probably will never know.
Cheers
Ray

[Deleted]

G'Day Maurie & Ray

Interesting story. Sometime back the topic of "Towball weight " was touched on. Towball weight was expressed in the amount of weight forcing down on the towball. Maurie mentioned that it took 5 blokes to lift the van back onto the new towball. This seems excessive in anyones language.
Given that each bloke could contribute up to 80 or a 100kg each to the lift this would mean a towball weight of almost 1/2 tonne. a big ask for a small ball especially if the van has been towed around australia??

Metal fatigue!!!

I aint no injuneer but i know that it is good engineering practice not to machine stress points at a right angle as is the case of tow ball threads where they meet the ball flange that sits on the top side of the gooseneck. Always thought it would be better to leave a radius of some sort when machining these things up.
Just another one of my half baked theorys.

What Ray has suggested is probably right . a loose ball flogging backward and forward combined with excessive towball weight would certainly cause metal fatigue and become a recipe for disaster.

Good to hear you played the good samaritan Maurie . I am sure anyone of us who come across this type of thing would have help the old couple out.

Cheers
Reddo

[Deleted]

Hi All
Further to this thread.

The fairway van is fitted with a 2 5/16" coupling . the old bloke handed me an old cast 2 5/16' ball complete with 5/8" cuphead bolt through the middle. I used it to tow the van home. All the while thinking about mauries horror story. got home OK.

I ordered a 2 5/16" machined ball last week from ISP.
$63.... .
I went down yesterday to collect it and found that the thread diameter is about 1 1/4". So my plans to leave everything original on the van coupling and just fit a later/safer style of ball was buggered up.

I took the ball back and have now bought a 50mm mechanical overide coupling as well as a new seperate base plate to replace the old setup.

lesson learnt ... dont stuff about with old setups . spend the bucks and upgrade.

Reddo

[Jim]

Hi Col.

Something doesn’t quite add up with the weights you’ve stated for the different towballs.

Maybe the weights are pounds, not kg’s?

3500 lbs = 1590 kg’s .. and .. 5000 lbs = 2270 kg’s
The kg figures make more sense for non complying towballs..

It’s common on cheap towballs to state the weight in pounds, such as 3500 lbs to give the impression it’s 3500 kg’s, which is the requirement under the ASA Standard for towballs.

I’m sure I’ve mentioned this before, towballs have an Australian Standards Association rating..
The standard is..ASA 4177-2

In fact the Standard requires the marking to be “3.5 T” on the small flat top of the ball (not 3500 kg’s).

It’s difficult to imagine a marking of 5000 kg’s when the Standard only requires 3.5 T.
Besides, towing regs over 4.5 tonnes are a whole different ball game.

If you’re going to buy a new 50mm towball buy one that complies with ASA standard 4177-2.
Oddly they are often the same price, or cheaper, than a non-complying one.

That said, its only 50mm towballs that have the “standard” (as do other current tow hitch components), but NOT older Imperial size towballs (less) commonly found on older vans and trailers.

But as this is a vintage van site with lots of old stuff, people on here should be aware of what’s available and how standards have developed and changed.

I don’t have one on hand at the moment, but I salvaged this wrapper from the bin.
Look for the ASA standards marking 4177-2.

[Jim]

Something else to consider if you’re thinking about the weak links in the towing system..

I’ve seen older towbars with removable tongues that have two ½ inch bolts instead of two 5/8 (16mm) bolts.
These bolts are in sheer with the total weight of the van as well as tension with the download.
Upgrade if necessary and make sure those bolts are good quality and tight.

A further consideration is vehicles with heavy load distribution hitches..
The total load is in sheer on one 16mm pin.

Chain attachments should be on the main frame of the towbar, not on the removable part.
Any shackles used should be rated at the least the same, or higher, as the chain it’s fixing.

[scootman]

Jim you wrote
"Something else to consider if you’re thinking about the weak links in the towing system..

I’ve seen older towbars with removable tongues that have two ½ inch bolts instead of two 5/8 (16mm) bolts.
These bolts are in sheer with the total weight of the van as well as tension with the download.
Upgrade if necessary and make sure those bolts are good quality and tight.

A further consideration is vehicles with heavy load distribution hitches..
The total load is in sheer on one 16mm pin.

Chain attachments should be on the main frame of the towbar, not on the removable part.
Any shackles used should be rated at the least the same, or higher, as the chain it’s fixing."


I READ "ASDKFJAIDUS SIDUFAWEJRF IASLIKHFLWIDJLI ASLDFHLKADHFKLDJ ALSKDJFLAKSDJF ALSDKFJ ALSKFJ ASKLJ$E)"%RTKLF<MODRIT)(EE )E(R)_( #$)(%)FODKOF )#()#(%#())E( DLRIOE .

Please explain.

[Jim]

I'm not sure what all that gobbledygook is at the bottom of your post Scoot.
Is it redhead fish shop owner mode maybe??

There are three points I was making about what may be weak links in your towing system.
It may not be the towball that's the weak link, although it probably gets more attention.

1.. The bolts on a removable tongue.
2.. The pin in heavy duty hitch assemblies, such as (but not confined to) Hayman Reese.
3.. Chain attachment points and shackle load ratings.

Is that what you meant?

There are other things as well, such as..

Some removable tongues are ridiculously long.

Some older (poor design) towbars fitted on older cars have very little in the way of load speading mountings.
They have little resistance to twisting and are probably only suitable for a 6x4 trailer with a load of prunings.

A classic mistake is to hook up an older van with a 2 inch coupling on a 50mm towball.

And on and on it goes -- the point being, look further than just the towball.

[scootman]

Thanks James

[Deleted]

Hi All

Jim . All valid points you have alerted us to. One other i was told of not so long back is .
Where trailers or vans have two safety chains they should cross over before attaching to the tow vehicle. Again i am not sure why but i was told by the mechanics here at the council that was the correct procedure.

Also the new 2 5/16" towball that i had to order up from hayman reece was chromed and rated at 1000 lbs.
I remember glancing at it when i was handing it back.
and seeing a "1" followed by a string of "0"s . i doubt if it was 10,000 lbs.

Chroming does affect the metal. a few blokes in the bike club had their bike wheels laced up with chrome spokes at the same time i had mine done in stainless. there is about a dozen bikes in the club that have been running stainless spokes for years without a problem.
Each of The blokes that installed the chrome spokes have had problems with spokes snapping at the cross over points.


Reddo

[groovy]

The purpose of crossed safety chains is, if the van does come of for any reason, the chains will cradle the drawbar and stop it hitting the ground.
Greg