Outer Limits 4x4 Board

Question:
Can you increase a vehicle's legal towing capacity and have it certified by modifying the vehicle by say, engine suspension and brake modifications, or does it have to do too much with weight?

Chris

I'm also interested in this......

Yes it also depends on the wieght of the vehicle.The vehicle has to be able to control to certain extent what is being towed.Improving the vehicle as you stated would if that vehicle was rated a low towing capicty due to a small motor crappy brake etc bring it up to it`s max towing capicty with the weight of the vehicle taken into account.
Cheers

In SA ... no

Tried for two years to get the towwing capacity of my Navara increased

My understanding is that no matter what you upgrade you can never get the towing capacity increased past what the manufacturer states as the maimum.

So even when you have a landcruser and you do a 6 wheel conversion and get the carrying capacity increased you still carnt tow anymore than a stock cruza.

One example is a current model F250 which has a towing capacity of 3500kg in Australia. My understanding is that if you get a engineered tow bar that allows 4500kg you can get it engineered (in Qld) to tow this amount because the manufacturer states (in the US) that the vehicle can safely tow this amount. Dont know of any other light vehicle that this happens too.

Sam

There was a black F250 in 4WDmonthlly a few months ago that supposedly had it's capacity upgraded. Not sure if it was load/towing/combo or whatever, or exactly how it was done though.

-Stu

[quote="One example is a current model F250 which has a towing capacity of 3500kg in Australia. My understanding is that if you get a engineered tow bar that allows 4500kg you can get it engineered (in Qld) to tow this amount because the manufacturer states (in the US) that the vehicle can safely tow this amount. Dont know of any other light vehicle that this happens too.

Sam[/quote]

thats scary seing its hevyer then the f250 to start with then upping it to allmost doubble the weight of the tow car. rangerovers and early discos were rated at 3500kg also for a braked trailer but that iilegal as far as im aware in every state of australia. just because ford or land rover say thay can tow it does not mean its safe in nsw what you can tow can only make a certan % of the weight of the car towing it. and in australia it dont matter if your in an f truck or a 120y with out trailer brakes its iilegal to tow more than 750kg includeing the trailer

NZ has a werid way of doing it. simply put you have to "stop withen 7m at 30km/h" and that about it. you can legally tow 2.5ton (braked) with a mini if you wish provided you can stop in 7m at 30km/h. it can be on any rated tow bar, the only thing needed to be rated is the trailer coupling. however if you snap the towbar no doubt you willl be done for overloading.

in NZ you don't bother about upgradeing a vechile for towing because manafacturs towing limits don't apply.

thats scary seing its hevyer then the f250 to start with then upping it to allmost doubble the weight of the tow car.

Question - What happens with trucks, B-Doubles, Road Trains then?
The rig is no where near the same weight as what they are leagally allowed to tow.

460cixy wrote:in nsw what you can tow can only make a certan % of the weight of the car towing it.

NSW/ACT changed their rules a few years ago to fall in line with the rest of Australia. Manafacturers specified limits apply, and on vehicles with no specified limit it is set at 1.5 times the tare weight of the vehicle.

What about 5th wheel conversions?

I have been looking into this and spoke to aranda tow bars about getting stuff up graded and approved ,but they didnt think it was possible.I have a 7 metre haines signature i want to tow home from the mariner but i dont want to ditch the hilux,i have a 2001 model falcon ute in manual form ford only rate it to 17ookg in auto form the same car is rated to 2350 kg,try explaining that ,cause ford cant.

Jeff80 wrote:

thats scary seing its hevyer then the f250 to start with then upping it to allmost doubble the weight of the tow car.

Question - What happens with trucks, B-Doubles, Road Trains then?
The rig is no where near the same weight as what they are leagally allowed to tow.

If you tow with a 5th wheel (as semi's do) then the limits are different. Lots of people in the US and UK fit a 5th wheel to a ute if they want an increased towing capacity. Don't know if it is possible in OZ though???

ISUZUROVER wrote: If you tow with a 5th wheel (as semi's do) then the limits are different. Lots of people in the US and UK fit a 5th wheel to a ute if they want an increased towing capacity. Don't know if it is possible in OZ though???

There's more focus on licensing in Australia than the states. That is a major factor into vehcile weights. You can technically build a f250 to move 6-8 tonnes gross combination, whilst keeping it within the limits of a car license, but the question of wether a person with a class C license can handle it.

If you need to haul this kind of weight than you have to look at trucks and truck licensing

Jeff80 wrote:

thats scary seing its hevyer then the f250 to start with then upping it to allmost doubble the weight of the tow car.

Question - What happens with trucks, B-Doubles, Road Trains then?
The rig is no where near the same weight as what they are leagally allowed to tow.

semi trailers put 50 percent of the trailer weight on the prime mover, opposed to a 'pig trailer' that puts maybe 10 percent max on the tow ball, and the rest of the load tries to balance on an axle setup somewhere in the middle of the trailer.

as a result handling with a semi trailer is different, and alot safer than any possible car/trailer configuration

In the ACT it is possible. Two guys in our club ungraded the towing capacity of their TJs approved by ACT RTA. They have gone from 900 braked to 1500 braked (to tow caravan / campers). Engineers report required. They had rear disc brake conversions and also custom (engineered) towbars I believe.

If you tow with a 5th wheel (as semi's do) then the limits are different. Lots of people in the US and UK fit a 5th wheel to a ute if they want an increased towing capacity. Don't know if it is possible in OZ though???

Does anybody know the technicalities of a 5th wheel conversion in Oz?

Im looking at doing this to my ute

bastard wrote:I have been looking into this and spoke to aranda tow bars about getting stuff up graded and approved ,but they didnt think it was possible.I have a 7 metre haines signature i want to tow home from the mariner but i dont want to ditch the hilux,i have a 2001 model falcon ute in manual form ford only rate it to 17ookg in auto form the same car is rated to 2350 kg,try explaining that ,cause ford cant.

I think it was because its a manual when i use to fit towbars (hayman reece) ford said was cause people were burning the clutches so they gave it a lighter rating

Jeff80 wrote:

thats scary seing its hevyer then the f250 to start with then upping it to allmost doubble the weight of the tow car.

Question - What happens with trucks, B-Doubles, Road Trains then?
The rig is no where near the same weight as what they are leagally allowed to tow.

A believe the weight ratio is spread between the rig & the trailer rather than all being on the trailer, they are also driven by drivers licenced & train to drive such combinations.

Rainbow Warrior wrote:

Jeff80 wrote:

thats scary seing its hevyer then the f250 to start with then upping it to allmost doubble the weight of the tow car.

Question - What happens with trucks, B-Doubles, Road Trains then?
The rig is no where near the same weight as what they are leagally allowed to tow.

A believe the weight ratio is spread between the rig & the trailer rather than all being on the trailer, they are also driven by drivers licenced & train to drive such combinations.

and they are fun too!

How do you find out the towing compacitiy,Ring the local dealer?

4sum4 wrote:How do you find out the towing compacitiy,Ring the local dealer?

for Toyota`s 84 and up ring 1800252097

and for years lower it goes by 1.5 times the tare weight

A truck and trailer (or ute and trailer) become a "semi" (or "5th wheel)when the trailer is attatched to the tow vehicle ahead of the centre line of the rear axle group (or rear axle for a ute).

The easiest way to explain the increase in weight allowed by this is to think of the combinations whilst braking.

When a vehicle with a "pig" trailer is braking the weight transfer goes from the trailer to the towbar which is usually a fair way behind the rear axle. This pushes down on the towbar and lifts the front of the vehicle potentially causing instability through reduced steering ability.

When a "semi" brakes the weight of the trailer is still thrown forward, but instead of being pushing down on the towbar behind the rear axle it pushes down on the turntable in front of the rear axle and this also transfers a proportion of the weight transfer on to the steer axle as well.

You will find the actual capacity of the F250 in the example previously mentioned is still the same GCM (gross combined (tow vehicle and trailer) mass) but because the trailer throws weight ahead of the rear axle instead of behind, the weight of the trailer can increase (so long as it doesn't exceed the manufactures GCM)

Confused still??????

I know 2 guys that have fitted 5th wheels to vehicles, one was a TD GU and the other was a Mazda T3500.

The guy with the GU did it to tow his race car and the other guy did it to tow a huge 4 horse float.