question to think about

Good question Steve. I don't know the answer but I have been fortunate enough to break just the one over the Million odd towing Km's I've done and that was put down to a stress fracture probably from production (so I was told). My towballs have been changed with the purchase of each new vehicle so my current towball has probably done the most Km at 240000km, also the heaviest loads have been on this vehicle. Will keep an eye on this thread to see if any experts have a real answer for you.

Cheers Trevor.

IMO it should be a rated ball from a reputable manufacturer to start with. There's a lot of cheapie imports on the market which personally I just dont trust but a tow ball shouldn't break at all if it's only used for it's intended purpose: towing.

But when a stored energy load is put on it as in a snatch strap the force can be more than the ball can handle.
The weight of the 2 vehicles, the resistance of the stuck one and the stored energy or inertia of the snatch strap is astronomically high and can and does snap tow balls or the welds around the tongues. I read the calculations for all this on a couple of other forums and although they were only approximate they were still high forces.

You shouldn't need to change your tow ball unless it's been subjected to loads like these as I believe that they fatigue the metal over time and eventually it may let go.
A common and safer method of rear snatching is to remove the hitch and put the loop of the snatch strap into the hitch sleeve and refit the high tensile pin through the loop of the strap.
You need a hitch reciever type tow bar to do this of course or even better get some rated recovery hooks or recievers fitted.

Hope this helps.

Don't have that sort of problem.

Both the off-road trailer and Camper I own use the Treg coupling. Much better solution and totally quiet too.

Dont know Steve

I had a 2 ton rated tow ball and towed the 27footer for 200,000km and then one day....snap!!! Caravan lurched forward and re arranged the rear doors of the FJ55. Luckily I was only doing about 10kmh.

I have a towball for the box trailer and a Treg for the Off Road Trailer

Maybe you should have two towballs and change them around every year or so. Dunno, just and idea.

Cheers