Increasing the ATM on my Windsor Caravan

Submitted: Friday, Oct 24, 2014 at 12:00
ThreadID: 109915 Views:4879 Replies:6 FollowUps:8
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We travel & live in our 19.6 Windsor Genesis and I have been worried about the payload restrictions.
I made some enquiries around Townsville (as suggested on a previous thread) and found an engineering firm (recommended by a couple of caravan sales people) and had them give me a quote to take the ATM up to 3000kg from 2243kg, their recommendation.
Labour: Raise van, remove spring pack & hangers fit new hangers & 3-4t spring packs to meet requirements $950.00 Alco Spring kit $936.00 Engineers inspection and new compliance plate $586.00= $2472.00 plus unknown cost of consumables & envioronmental disposal.
I'm happy with their service and whilst the cost seems more than I ever dreamed of I have booked it in for next Wednesday.
Do I need to increase to 3000kg? My Nissan Patrol will pull it OK
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Reply By: The Bantam - Friday, Oct 24, 2014 at 12:26

Friday, Oct 24, 2014 at 12:26
HELL, that is a near 50% increase......serioulsy do you need to carry another 3/4 tonne of stuff.

As for the nissan pulling it.....UM have you checked the carrying and towing capacities in detail.

Remember the payload of the tow vehicle will be reduced by the attached load and ball weight

check your
Agrigate trailer mass
trailer GVM
Vehicle GVM
Gross combination mass
permitted ball weight of the tow vehicle...remember tow vehicle payload is reduced by the amount of the ball weight.
tow vehicle maximum axle loadings in particular rear axle.

All in realtion to how the vehicle combination rolls now..and how it may roll once modified.

Oh..have you weighed it...with all aboard.

how does the tow vehicle sit as far as the current loadings...will the tow vehicle be overloaded with the increased trailer ATM and ball weight.

AnswerID: 540794

Follow Up By: Member - Peter M (QLD) - Friday, Oct 24, 2014 at 13:14

Friday, Oct 24, 2014 at 13:14
Thank you Bantam. You are so right.
I have just sent an email to the engineering firm to re-quote to raise the ATM to 2500 or 2600kg.
All the initials confused me plus the GM of the engineering firm gave wonderful service he called out to inspect the van on his way home from work and I just accepted his advice. Without working out the numbers.
The only numbers that I realy looked at were the dollar numbers.
Thank you again
PeterM (Qld)
FollowupID: 826685

Follow Up By: The Bantam - Friday, Oct 24, 2014 at 14:54

Friday, Oct 24, 2014 at 14:54
There are some very good pages and booklets about the various load limits.
Possibly the easiest to access is in the back of the caravan parks guide.

But a quick run down.

GVM ( gross vehicle mass)of the trailer is that mass that presents at the wheels of the trailer
Ball weight is the mass of the trailer that presents it the ball.
ATM...agrigate trailer mass is the whole mass of the trailer....the GVM pluss the ball weight.

Tow vehicle GVM is that which presents at the wheels of the tow vehicle.
That is the total mass of the vehicle including its occupants, accessories' load AND the ball weight.

GCM, Gross combination mass, is the toal mass of the vehicle and the trailer it tows and everything in or on them.

Permitted axle loadings are the maximum load that can appear at each axle.

Curb weight...ahh well that is a beauty....that is the weight of the car as ir rolls off the production line with the sump and radiator full.....but with the fuel tank only partly full.

Payload is that which the vehicle can carry after alll fuel tanks have been filled, the weight of all permanently fix accessories and the like have been taken into account.

The irritating this is and a couple of other things are specified and legally regulated....BUT...they are not all to be easily found in the one place on a passenger car or in the manual....if they are there at all they will be strewn about the car and the manual.

In the heavy vehicle business, if you own, manage or drive a heavy vehicle, you are an absolute fool if you do not know these figures or have them available for immediate reference....and they are generally redily and prominently documented......many vehicles have them painted on the side or printed somewhere redilly viewable by the driver.
AND they are considered important in sales documents.

But unfortunatey our passenger cars all we seem to hear is towing capacity.....we have to trawl thru the manual to find them on different pages and different sections and GCM may not even be in the documentation the owner recieves.

Peter mate...time to do some homework and find out what all these figures mean and what they are in relation to your vehicles.

Most of the station waggon 4wds have very poor payloads in the range of 600KG some of them.
It is possible to find them overloaded with bullbar, rear bar additional spare wheels, roof rack, two average people and their bagan aboard.

Remember if you have a 300KG ball weight ( 10% of a 3 tonne trailer) and two 100kg people aboard....that don't leave much to spare...and that is no bullbar, winch roof rack or long range tank. you go do your homework....then go down the nearest public weighbridge ( most tips and gravel yards) and see how she goes over the scale........don't forget to take your heart pills.

FollowupID: 826694

Follow Up By: TomH - Friday, Oct 24, 2014 at 15:22

Friday, Oct 24, 2014 at 15:22
Kerb weight is normally taken with full FUEL tanks included

Tare weight is dry weight as you describe and normally with 10L of fuel.

Another thing to consider when upping the ATM of a van is.

A. Limit of brakes, they come in different ratings
B Springs The same
C. The rating of the chassis 2.5T or 3.0T, its stamped on it
D. Axles also have weight limits
E. Wheels and tyres all have weight limits.
F. Axle group rating.

Also Nissans are notorious for having reduced ballweights above towed weights of 2500KG.

All should be considered before paying out the money.

I had a Roadstar done and all it entailed was a check of each of the above. Mine was limited by the Chassis which was rated at 2500kg.

It only cost $475 for the certification plate.
FollowupID: 826696

Follow Up By: The Bantam - Friday, Oct 24, 2014 at 16:00

Friday, Oct 24, 2014 at 16:00
I think you need to check your facts on kerb weight.

It may in fact vary from manufacturer to manufacturer and differ depending on the market the vehicle is sold in.

it pays to check what the kerb weight actually means for that manufacturer and that vehicle.

If the vehicle for instance has two fuel tanks totalling 160 litres and the kerb weight only accounts for one tank being half full....hmmm yeh that is an issue.

various definitions I have seen.
fuel tank full
fuel tank half full
30 litres of fuel
45 litres of fuel
Primary tank half full.

Its not a regulated term ands can not be relied upon to be standard world wide.

FollowupID: 826699

Follow Up By: TomH - Friday, Oct 24, 2014 at 17:12

Friday, Oct 24, 2014 at 17:12
Not entirely sure about Nissans but 200 ser Toyos kerb weight is with full tanks Nissan weights are shown all over the place.

One shows 1907 tare others show 2345 so who would know.
Just make sure it doesnt exceed GVM with van attached
FollowupID: 826704

Follow Up By: The Landy - Tuesday, Oct 28, 2014 at 17:12

Tuesday, Oct 28, 2014 at 17:12
Perhaps “Kerb Mass” and “Tare Mass” being confused here.

Kerb mass is usually unladen with all resevoirs filled, including fuel; tare is unladen with all resevoirs filled, with exception of fuel which is 10 litres only.
FollowupID: 826917

Reply By: Member - Jim B8 - Sunday, Oct 26, 2014 at 07:52

Sunday, Oct 26, 2014 at 07:52
Well I didn't know that the ATM was able to be altered, but there you go, it is. I knew about altering the GVM of the tow vehicle.
This is one of the least understood items on the road I reckon, there is so much detail and acronyms involved, that confusion reigns, this topic surfaces all the time. We need an expert to spell it out. And I am not that person ha ha. But one thing I was told, is that the gvm (and it appears the ATM) be altered, the GCM can never be altered. - Meaning, if you load more on the tow rig, the same weight has to be removed from the item being towed. And vice-versa, increase the van ATM, and the same weight must be removed from the tow rig, to keep the GCM the same. Combined mas cannot alter ever (I was told)
Correct me if I am wrong, that's just my understanding. I think Bantam alluded to that above as well?
I would not alter either GVM or ATM, myself, I would look at the loading, remove what is "nice" but not "needed"
Or crack a beer, and consider upgrading the tow rig, or downsizing the van....A lotto ticket?
AnswerID: 540867

Reply By: Slow one - Sunday, Oct 26, 2014 at 08:20

Sunday, Oct 26, 2014 at 08:20
Peter M,
could you tell me the company that quoted to raise and compliance the ATM in Townsville as I have a friend that needs to raise his by 100kg.

Thanks, very slow one this morning.

AnswerID: 540869

Follow Up By: Member - Peter M (QLD) - Sunday, Oct 26, 2014 at 12:24

Sunday, Oct 26, 2014 at 12:24
G'day Slow One
The company name is: ADiT Engineering 4755 5222
I was given their name by an engineer at Rupertswood: Christian Avendt; 0400 699 656 or 4788 7412
I'm waiting for a new quote to raise the ATM to 2.5t which will keep it under the towing capacity of the Nissan and will be far more than we need.
I'm sure we travel at just on the current load capacity without water but I would like to be able to travel with water and both gas bottles filled and not pay any State Government any extra taxes
peterM (Qld)
FollowupID: 826767

Follow Up By: Slow one - Sunday, Oct 26, 2014 at 16:38

Sunday, Oct 26, 2014 at 16:38
Peter M,
Thanks for that and I will pass it on as he comes from up that way.

He has the same problem with being just overweight with a full load of water.
FollowupID: 826778

Reply By: PeterInSa - Sunday, Oct 26, 2014 at 17:40

Sunday, Oct 26, 2014 at 17:40
Been there, Done that.
You may be interested in.......

AnswerID: 540887

Reply By: Droving on the long plain - Tuesday, Oct 28, 2014 at 13:03

Tuesday, Oct 28, 2014 at 13:03
G,day Peter M,
I read your thread and replies from others, if you increase the ATM as you suggested your quoted figures ma be fine did the engineering firm check the vans axle carrying capacity. the axles should be stamped to their maximum carrying weight. The van GVM can not exceed the axle loading.
Good luck,
Droving on the long plain.
AnswerID: 540972

Reply By: Nomadic Navara - Tuesday, Oct 28, 2014 at 16:19

Tuesday, Oct 28, 2014 at 16:19
I'm not sure who makes the chassis for Windsor vans but some of the larger manufacturers attach a chassis makers plate. This is in addition to the compliance plate the van manufacturer attaches. The chassis makers plate will have a maximum weight for the wheel load. Alternately the compliance plate may have a maximum axle load figure on it. You can have the GTM of the van increased up to that figure without having any chassis/axle upgrading. Then the ATM will be the GTM plus your ball weight (have the ball weight measured with the van loaded, vans commonly have increased ball weight when they are loaded.

If that increase will suit you then your upgrade will only be $586 for the engineering inspection and compliance plate issue.
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AnswerID: 540984

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