GVM staying within the law
GVM and what are the complications with building your next 4wd.
We have all heard about it, we have all read about it. Gross Vehicle Mass (GVM) and in building our Ford Ranger for touring I was surprised to find out, just how close we were to our GVM.
So, you go and buy a brand new 4wd. You ask at the time of purchase to put on frontal and side protection, as this is what we all want when we travel outback roads. After a few weeks we found our vehicle to be sitting on the front bump stops. When we asked ford about it, we were told most people throw away the factory suspension and put in aftermarket, and so the build begins.
We have always run Tough Dog 41mm bore shockers, with a 2-inch lift. You only really get around 40mm once it settles in, but we were happy with that.
After a couple of trips, we found once more the factory bash plates are completely unsatisfactory for off road work. After nearly putting a basketball size rock through the front factory bash plate and nearly damaging the radiator we decided to opt for a full ARB under body protection kit with recovery point to match the ARB Summit bar and rails.
Now we have a vehicle starting to look like a 4wd. Thinking about not getting stuck in the mud we added a winch, which come on boys and girls we must admit is on most wish lists. So now we think we are getting there, 4wd is looking good, we are set and ready for the tracks.
Now its time to get out and get the rig dirty, chuck in the food and a bit of firewood, hitch up the camper to the back and we are off on our adventure. Making memories along the way.
This is where the complex weight of the GVM starts to show its ugly head. Creeping up on you like a bad dodgy vindaloo.
Let us take a quick step back to when we bought the Ranger.
New – 3.2 litre T/D motor. 147kw and 470Nm@1750-2500rpm. Factory kerb weight of 2278kg. GVM of 3200kg. Add a 6-speed auto and rear diff lock, oh what more would you want. We get a massive 950kg payload and a fair 3500kg towing capacity with a gross combination weight of 6000kg that is more then acceptable for a touring rid, Right?
Here is where the Dodgy vindaloo creeps in.
- ARB Summit Bar – approx. 70kg
- ARB underbody protection including recovery point – approx. 40kg
- Side rails and steps – approx. 40kg
- Winch – approx. 25kg
- off road tyres and rims – approx. 10kg heavier each than standard per corner.
Remember these are just the simple things we all want in a touring rig, but the weight slowly adds up. 215kg is nothing to sneeze at, and most of it on the front axle.
So, after a few more trips we decided to change out our tub and roller shutter for an aluminium tray and Canopy set up. We have all seen these driving around, Spare tyres hanging off the back, aluminium boat on a roof rack or roof top tent. They look the ducks nuts.
Well I ordered our tray, jack off canopy and kitted it out with a fridge and second Battery. Wow this made touring and trips way easier to manage, but now the rear of the Ranger looks a bit saggy with the camper hooked up.
So, I thought we better measure the tow ball weight to see what it was on the Tvan, only to shock me of a weight of 180kg.
Here is the thing about GVM in our 4wd’s we build up. Take the 200 series Landcruiser for instance. Add the weight of all the protection gear, add the camper ball weight to the rear plus a berley bloke of 120kg and the handbrakes weight (aka the missus) fill the fuel tanks full and pretty quickly we are getting close to our 660kg payload we can have without even putting a set of rear draws or tinny on the roof.
This got me thinking about the Ranger. Off to the weight bridge with the new tray and canopy set up. First, we weighed the rear axle without the canopy, and it came in at a reasonable 1080kg, this included a full undertray draw and side toolboxes, fitted out with tools and recovery gear. Standard tare with a ute tub was 1019kg, not bad. Then we placed the canopy on and put it back on the weight bridge and added another 380kg so up we go to 1460 kg over the rear axle. This we thought was a good weight to be at. With a maximum rear axle load of 1850kg it gave us 370kg we could pack into the canopy of food etc.
Boy we were wrong.
At this moment we thought all is good. Plenty up our sleeve. We put the entire vehicle on the weigh bridge, with me in it and a quarter of a tank of fuel the rig came in at just on 2980kg. ‘Holy cow’. Now this is the part we all forget, put on the camper. Remember the ball weight? 180kg now we are adding to the GVM of the Ranger, 3160kg. Its looking like the handbrake must walk to camp. Remember the Ranger can only weigh a maximum of 3200kg not a lot left for packing.
To stay within the law, we must seek a GVM upgrade, and with only a few suppliers being able to meet the standards we went back to ARB at Jacksons 4×4 to upgrade our vehicle.
The recommendation was OME BP51 with 600kg constant load leaf springs in the rear. Once engineered this will give us a GVM of 3500kg for the Ranger.
After been through the entire roundabout of GVM weights to find out we were close to our max capacity of our vehicle it’s really important to make sure you are properly informed about the weights of the accessories you are about to put on your beloved 4wd. Our experience over this build, no one pulled us up on maximum axle loads. No one tells you the weights of their products they sell. Do your research, make sure you know how much all the bolt on aftermarket product weights, other wise once you have packed and set off on your adventure’s, you just might fine yourself on the wrong side of the law.