Tow Ball weight

Quote "Most vehicles do not have suitable shock absorbers to be able to cater for the additional forces and mass transfer of weight distributing hitches. Upgrades of shocks would be the most important item on my list. Without the control good suitable shocks provide an emergency situation is often called an accident."

Ross, where did you glean that little gem from. Can you please supply me the links so I too can be educated.

Ross,
Light ball weights on long heavy vans spells disaster in the making.
While 10% has been the accepted level for may years research and testing has show that it is indeed a good starting point, but longer heavier vans may require even heavier ball weights up to 15% to maintain stability.
I suggest you read articles by Colin Rivers (Google) for more information.
Ozjohn.

Nomadic Navara
The shock absorbers on most vehicles are usually only sufficient for the mass control of the vehicle mass and unsprung weight.

By adding a van to the equation the amount of mass to be controlled on side sway and porpoising is far greater and no OE shocks are really up to the task.
Not sure what you are on about with the "show me the links" comment.
Why does there have to be a link to something before anyone thinks a comment is valid. Having had a lot to do with shock absorbers and their operation, shockers should be matched to a situation, adding a van alters the situation quite considerably, but as usual no one really cares about it or even considers the situation to be different, possibly because it never enters their heads and isn't the normal issues talked about. Poor/unsuitable shock absorbers cause more accidents than people realize.
Monroe company has the Motto "Don't discover your shocks are worn by accident"
Most Japanese based vehicles like Navara, Dmax, Colorado are fitted with shocks only good enough to sell it but not for the work it is designed to do. Most do not dampen at all well after 30,000km and that is for the vehicles weight only, no extra.

ozjohn0
I haven't mentioned having the ball weight insufficient for stability just don't have too much.
The tow vehicle characteristics ie suitable suspension, body roll control, matched shockers, appropriate tyres sizes and inflation and the distance from drive axle to towball, all play a huge part in inherent stability. Unfortunately people think it is all to do with the caravan.

Ross M
A grade Automotive Engineer

Ross – you’ve suddenly become an engineer.
You previously described yourself as a technician.
Have you just been accepted by The Institute?

Dennis Ellery
I can list it all but I thought I would put it into perspective for electrical engineers.
Listing credentials doesn't improve the road handling of a tug and caravan but suitable loading, suspension, and shockers fit for purpose sure do.
PS I'm not describing myself at all. Accredited Automotive organisations do that.

Hi Ross,
I know you didn’t mean degree qualified engineer but rather a title awarded by an automotive organisation.
It’s pointless listing your engineering qualifications as they mean different things to different people.
Old steam engine drivers and some mechanical and automotive tradesmen call themselves engineers.
When I was working, I used to hire out engineers to consulting engineering companies and government departments.
I came across a lot of self-titled engineers who lacked the qualifications that would entitle them to be classed as engineers by our clients.
The clients required engineering degrees issued by recognised universities, or eligibility for membership of the Australian Institute of Engineers
Dennis Ellery
Aeronautical Engineer, Electrical Engineer, Mechanical Engineer, Structural Engineer, Doctor of Bulldust and too many more to mention LOL.

What has all that got to do with towing a caravan and having a safe vehicle to tow it with?
It sounds like you have been a theoretical desk jockey and not someone who has necessarily had experience with anything mechanical.
I am confident I could diagnose your vehicle and you seem to not value the people who can diagnose and repair your vehicle.
I have seem this before.

Qualifications are just one aspect of life, experience and ability to apply it is another.
I know my capabilities and don't care if you feel the need to continually dispute issues with others.
Oh, how are your shock absorbers going, do you really know if they are ready for the all important emergency you may face on the road even at 80 or 85km/h while towing the van. If you value your life and your wife, it might be best to know if they are suitable for purpose or not. Comment based on experience not qualifications.

Good luck and all the best in your future motoring.

Ross M

Hi Ross,
I didn’t mean to denigrate your experience.
My mechanic says I have two stuffed rear shock absorbers on my Troopy.
What would you suggest as a replacement – towing a 3 tonne van with a towbar ball weight of around 200kg – mostly for highway towing?
Regards Dennis

Is is a sad situation when you "come the bounce" with people who are trying to tell you something.
I feel sorry for you if you can't tell your shock absorbers are stuffed and need a mechanic to do it for you.
If they are stuffed, you would have been able to feel the progressive degradation of the performance over time and change them. Any undulating road will tell you.
There are very few shock absorbers which have a lasting performance past 50,000km. I changed three sets of ARB OME shocks on my 60 series in 150,000km. They don't last at all well, poor product for the money.
The ability to steer, brake and control the additional caravan mass, which is trying to tell the tug what to do, is of paramount importance.

If I drove your vehicle on an average road I will tell you within 1/2 a km if they are ok or not.
Unless the shocks are of well recognized quality they will be unsuitable for purpose long before the tyres are worn out.
Go with a Good brand not necessarily a popular brand.

Ross M

The shocks are original – done 85,000ks.
The ride feels ok but the mechanic noticed fluid on the outside of the shockies at the last service.
I will take his advice that they are on the way out.
Thanks for the info

Hi NN

Thanks for the input. Basically the two vans are the same. Both size and manufacturer. The difference on the two models is the position of the door, and an angled interior kitchen bench. Other than that all interior equipment is the same along with the fittings.
Our preference is for the angled bench design but in order to have this, they move the door, hence the difference in ball weight as it alters the postion of the axles on the chasis I presumme.

Cheers

High Peter - those are interesting studies.
It shows, amongst other things, that those large vans with centrally located wheels are inherently unstable.
Stability increases with high tyre pressures, heavy tow ball weights, centrally located loads and slow speeds.
I have such a van and travel between 80 to 90 ks an hour – much to the annoyance of others.