Load Plus Helper Springs

hi ditto to that

As to bending the chassis rails on a 'Cruiser, I did 400,000 hard kms in mine with PolyAir bags, more than half that carrying a heavy slide-on camper, off road, Tanami, Simpson, GRR etc without any problems.

Rob VKE237 Sel 6678

Always one thats different Did it have coils or leaf springs Nothing wrong with them in coils , its the ones with leaves that have the problems

Not coils Tom, just the bellows type bags with leaf springs, rode well and sat level even when fully loaded.

Rob

Peter

Spot on the mark

Cheers

Quote "and remember ball weight is part of the payload of the tug."

The loading on your rear axle is worse than most people think. The loading on the rear axle of your tug is amplified by the lever action caused by the ball being so far behind the rear axle. The extreme case for me was the overhang on my Disco. The distance of the ball behind the rear axle was 60% of the wheel base. That meant that the 200 kg ball weight of the van actually imposed 360 kg of loading on the rear axle. Many vehicles, particularly twin cab utes, have an overhang of around 50% of the wheel base. That means that a ball weight of 200 kg will impose 300 kg loading on the rear axle.

Many forum members sling off at the limits that Nissan place on their vehicles when vans are hitched up. The thing is that Nissan have worked out the de-rating needed when WDH is not used (because they recommend that it not be used on their tow bars.) If you are towing with other vehicles you need to work this out for yourself.

If you add the maximum weights for the two axles of a vehicle and compare that with the GVM of the vehicle you will find that the combined axle weights is very little more than the GVM. What this means is that you can load up the vehicle, including the tow ball weight and have the total weight of the tug not exceed the GVM but have the axle overloaded because of the way the loading is distributed by virtue of the loading remotely located behind the rear axle. Twin cab utes are designed to be loaded with passengers as well as the loading in the tub/tray. Even without a van it is possible to overload the rear axle if you load it up to its GVM but do not have 5 substantial people in the cabin.

Thankyou very much for your help. We are aware of weight but are finding because Landcruiser have all the tray as overhang (would have been smarter to put the dual cab on a troupe carrier chassis for a bit extra length) even an empty van has the tail dropping. But from your comments we will put more attention into working the weights more accurately but we still need something else as well. We did one trip with just air bags and they were great but we're a little worried about the weight being in one spot and then having the chance of bending our chassis that is why we are looking for a better solution.
I really appreciate your info as well PeterD.
I am guessing the WDH is a weight distribution harness. As our van is off road we don't have a tow ball set up and we have been advised not to use them as they take away the advantage of our hitch.
Again thanks for your help

Quote "I am guessing the WDH is a weight distribution harness. As our van is off road we don't have a tow ball set up and we have been advised not to use them as they take away the advantage of our hitch."

WDH = weight distribution hitch.

You did not mention the actual hitch you are using so no one can advise if it will take the strain. I know they can be used on the Treg hitches, a friend enquired and the manufacturer posted out the heavier block so he could use the bars on the Treg. Al-Ko has approved them on their hitches (including the anti-sway one.) The bars must be removed when you are travelling in off road conditions with sharp bends, steep bank creek crossings and jump ups. You will only be travelling slowly in those conditions so you can get away without the WDH. Check with your hitch manufacturer to see if the hitch is strong enough to take the stress of the WDH. If they are not then should you be using them in rugged conditions? (As an aside, you are supposed to remove them before manoeuvring around caravan parks and the like but very few do.)

Thanks PeterD we have a Treg hitch. I will chase up the manufacturer as well and check if we have the heavy block and if not will get one so we can also use the WHD.
Thanks heaps for your help.

Quote "BUT..... the problem and the poor solution is still with us ......... the problem is too much load on the rear of the vehicle ....... and making the rear of the vehicle stiffer or higher is not the best solution."

In addition, adding heavier suspension does not raise the carrying capacity or the axle that is carrying that suspension.