TRANSIT CAB CHASSIS GVM UPGRADE BEYOND 3500kg

[ramtec]

The VIN plate on my 1996 Transit Cab Chassis states axle group 1 limit is 1500 kg and axle group 2 limit is 2600 kg
GVM is only 3500kg which is 600 kg lower than the combined axle groups
Question: Can I upgrade the GVM to 4100 kg provided I do not exceed the axle group loads ?

[twin wheel camper]

The front axel should be 1600kg
As far as changing the gross weight it isn’t that simple I afraid.
You will have to prove the springs brakes etc are upgraded (even though there the same )
Also when you go over 3500kgs you need a tachograph and a haulage licence or whatever they call it nowadays that’s unless you do non paid work for yourself but for business use you have a heap of crap to get over when you gross over 3.5T.
Also not 100% sure but I think you have to have your van tested every 6 weeks and have paper work to prove it was done
You can do this yourself but you have to have a pit or lift to qualify, that’s what I understand but maybe I’m wrong but either way it’s a major bal**ache and just not worth it.

[ramtec]

Thank-you for responding.
Ok, Some more information sorry I didn't put this in before
I live in Australia and a standard car licence will allow you to drive a vehicle up to 4500 kg.
I believe in England that the limit is 3500.
There are no restrictions such that you mention on the vehicle, it only needs a roadworthy certificate similar to a car before it can be driven on the road.
There are no other stipulations made on the vehicle.
The Transit I have is being converted to a motorhome and the engineer that will certify the vehicle is reluctant to go outside the vehicle VIN plate loads.
I am confused that the axle loads are 1500kg on the front (which I accept is the limit) but the rear axle, dual wheels, can go to 2600kg as per the VIN plate.
Now that adds up to more than the GVM of 3500.
Is it the fact that to limit the vehicle to 3500kg it will allow anyone in England to drive this vehicle ? because if the the axle groups were added together (4100 kg) then that would exclude anyone with a standard licence from driving it.
All trucks that I know of in Australia the axle group loads add up to the GVM.
Why put a GVM lower than the axle group loads ?

[ramtec]

This is the VIN plate

[paul2012]

Here in the UK I've seen a T350 chassis cab (GVW 3500kg) fully loaded weighing in at 3920kg on the weighbridge at local yard.

You could see it was well overloaded to the point it didn't sit level. Axles may handle the weight. It's if the brakes are up to the job of stopping you.
With an increase in weight brakes will have to work harder & wear out faster.

[ramtec]

Yes I do understand that,
There are procedures for testing the vehicle braking system with heavier loads and that will be the case here. If the vehicle passes these tests then that will be included in the certification report.
There are air bag aftermarket suspension kits that will bring the ride height back to spec.

[Altransit]

The axle weights are there to make sure that you don't overload either axle, as it is possible to be legally loaded at 3500kg, but be overloaded on the rear axle (or front!) due to poor weight distribution of the load.
It does seem slightly bizarre, but basically, you can't load the van up to the max of both axle weights, due the the GVM being 3500kg.

You have to be mindfull of all 3 limits if you want to stay legal.

[ramtec]

Does anyone have experience with GVM upgrades ?
Please understand that this vehicle is a flat bed truck not a van.
I have increased the wheel base 820 mm and the rear overhang has gone from 600 mm to 1300 mm, the overall length is now 7580 mm
These modifications have already undergone FEA analysis and have passed inspection, of course the tray has gone and has been replaced by structure for the motorhome.
Due to the larger overhang I have placed the heavy items there, so that these items reduce the front axle load to be within the 1500 kg limit with passengers.
The rear axle is capable of 2600 kg as shown on the VIN plate so I therefore would like to increase the GVM by 400 kg to 3900 kg.
Axle loads would be 1500 kg front and 2400 kg rear (3900 kg total)
I know that there may be other modifications necessary to the vehicle like possible brake and rear suspension upgrades (although the rear suspension is allowed to go to 2600 kg as per the VIN plate so this should not be required)

[dumper]

When I had mk mk6 jumbo camper it was allways the wrong side of the gvw I contacted Sv tech hear in the U.K. and they said it could be uprated to 3800 kgs gvw by uprateing the surspention to 430 spec got this done but never did the paperwork side even before we uprated it by loading it right it never looked bad .as mentioned early in the post it’s right about the brakes as well as the surspention need uprateing to carry the extra weight my current van is based on a 460 Minibus and is running a lot more heavy but the braking is so much better and to honest the old van at times was scary even tho it passed the mot brake test no problem

[ramtec]

I cannot see why the suspension needs uprating .
The VIN clearly states that the maximum load on the rear axle is 2600 kg, so if I put a lower load than that, say 2400 kg, then I have exceeded the capacity ?
There is also a brake proportioning valve on the rear so when carrying a high load on the rear an adjustment must be made to the tension of the spring on the valve.
Thus putting more braking effort on the rear axle.
This vehicle has drum brakes on the rear which at first I was not in favor of, however most trucks including semi trailers use drum brakes ( these vehicles carry up to 40,000 kg.)

[dumper]

The load sensing valve is there to reduce brake force when not fully loaded so You don’t lock the wheels it’s not a matter of the more weight you put on the better the brakes you can only get the max design efficiency of the brakes when you overload them you don’t stop as well .as for drum brakes on hgvs their not many new ones on drums even the trailers are on discs

[ramtec]

I thought that is what I said but from the opposite view.
Less load less braking effort required (so you don't lock up the wheels)
I didn't say that the brakes would be more efficient.
What I did say is that more braking effort is applied when the load is heavier by adjusting the spring tension.
There is a graph on a decal near the VIN plate to do this.

[dumper]

Yes it’s sometime difficult to get in writing what’s in your head your van has not got abs as they don’t have a l s v and rely on abs to stop lockup so you’re getting full braking all the time it’s easy to do the mechanical upgrades but difficult to get paper work sorted

[MK7 user]

The VIN plate on my 1996 Transit Cab Chassis states axle group 1 limit is 1500 kg and axle group 2 limit is 2600 kg
GVM is only 3500kg which is 600 kg lower than the combined axle groups
Question: Can I upgrade the GVM to 4100 kg provided I do not exceed the axle group loads ?

In theory....yes.

Complete the appropriate paperwork, send it to DVLA, they'll send you a new registration document with the increased GVM, change the details the M.O.T. station need & you'll then need to obtain a new Vin plate that shows the new GVM.

I don't have a data sheet for a 1996 model chassis cab, but the 2600kg rear axle is not compatible with T350 suspension, so it will have been built with T420 rear suspension, so no modifications needed.

In practise....later models have a higher front axle loading, your 1500kg will be easy to overload using a 'uniformly distributed load'....so you may well be stuck with a maximum limit of around 3800~3900kg GVM.

There are plenty of coachbuilt motorhomes in the UK that have had a GVM increase....who does the registration documents in Aus?....I've chimed into more than one 'Outback Caravan Forum' & read posts about uprating a Landcruiser to 3900kg, so it can't be that hard.

[ramtec]

Thank-you for replying
You are the first person to come back with a positive reply
Do you know of any specific vehicles that have had a GVM upgrade so I can show my engineer a precedent ?
Kind regards
Tony