Anything related to motorhoming not covered in any other forums.
 #143736  by William
 Sun Aug 19, 2018 4:49 pm
Recently bought 1985 Isuzu NKR 552 motorhome ex rental made by "Classic Caravans and Motorhomes"in Levin back arround 1986.This has short wheel base,single rear wheels,2.770 cc diesil engine.Structualy sound for it's age.VGM is 4000 Kgs on the papers .I received full specs for this model from an Isuzu Truck firm in New Plymouth after doing a search on internet, because I suspected the rear springs were changed or altered at time of being rebuilt from truck and chassis to a full motorhome or at some stage by previous owners.The specs show the rear springs having 8 leafs and a "Helper" on each side.Ive inspected and counted only 5 leafs and no "helper" leaf. There is no certification paper showing the change/removal of leafs.Is there anyone who knows about rear truck suspension know if removeing rear leaf springs, or altering the rear suspension, change the VGM of a Vehicle or motorhome? Reason I suspected leafs were removed or changed is because the motorhome does not drive like a truck,infact it drives very smooth in the road like a car,so I checked the rear springs and noticed only 5 with no extra over riders or load helpers. With having spring leafs removed,I cant see the vehicle ever being able to carry up to a 4000kg load,even if it was a truck.Certified Tare of this motorhome fully laiden is 2.440.Thanks all answers appreciated.
 #143781  by Zukiwi
 Mon Aug 20, 2018 11:15 pm
William, the tare is irrelevant. It just describes the unladen weight of the fully constructed vehicle. The GVM is the important number as that is the maximum combined weight of chassis, body and load allowed by the manufacturer (and thus by NZTA). It is possible that your springs have been changed by a previous owner, but it's also possible that the manufacturer made the chassis available in different spring configurations for different uses. It's also possible that the springs still handle the GVM but are differently rated - ie they still carry the same load but respond differently to it (eg, softer ride).

Do you know the fully loaded weight of your vehicle? If it's not more then the GVM and it rides and handles as smoothly as you describe, you don't have a problem.

 #143782  by vansvilla
 Tue Aug 21, 2018 7:08 am
John, I suspect that William is looking to lower the GVM of his vehicle to something like, say 3495 Kg. Think WOF.
This being based on lighter springs than one would normally find on that cab/chassis.
William I suspect that the reason the springs are lighter is to improve the ride. One of the criticisms of truck based campers is that they rode extremely hard as the springs were more suited to heavier loads. Spring replacements were carried out by some, if done long enough ago there would be no certification done or required.
By the same token RUC wasn't based on GVM then either although the vehicle would still be subject to a COF at 6 monthly intervals as were Wolf's so no gain there either.
 #143785  by BUSRSQ
 Tue Aug 21, 2018 8:17 am
The removal of springs/overloads is common on buses built on Truck chassis, gives them a "softer" ride and most of the time the buses are way under the vehicles designed in GVM,
At a guess these modifications were done while being converted to a Mobile home.
Can you lower the Factory GVM, easy answer is nope, if you want something with a lower GVM( under 3495 kg ) then go buy one, regardless of what modifications has been done to your chassis, it is still designed with a specific GVM in mind, I am sure if you had $1000's to spare you could get your chassis re engineered to a lower GVM, but it would require most likely a bare cab and chassis as a starting point, and would be way cheaper to either a/ sell yours and buy something lighter and live with the compromise b/ live with the higher costs of owning what you have, c/ buy a new one and have it recerted to a lower GVM
 #144443  by William
 Wed Sep 12, 2018 4:13 pm
Thanks for all the replies.Yes back in the 80s here in NZ , it was common for rear suspension springs to be either changed or altered according to their use and never certified and in this case it was the assembly of the campervan from bare light truck cab and chassis,when it was done according to what Ive found out.After talking to a vehicle engineer with correct qualifications,Ive also found out that even though the manufacture's VGM of in this case,4000 kgs and is set by NZTA, the VGM may not acturly be correct after springs were altered,hence the suspension becomes part of the manufacture's VGM effecting the safety of the vehicle if it were to carry a full payload of 4000. The design of this campervan body being built longer than the chassis and very wide.The suspension was altered for comfort reasons while being built as a rental campervan. So if it was still a truck,evidently it would be totally unsafe to carry the full payload with a weaker suspension. As a campervan,the ruleing should be the same,therefor in this case there should be an allowance to lower the VGM and not to over load the vehicle above say 3500.This camper does not have a body that is attached to the cab.Instead there is a cut out of the rear cab window and a flexi arch that allows a person access into the camper body.I believe campers/motorhomes etc are in a class of their own once built and should be recognised /classed as such.If built commercially on a light truck body,NZTA can not still class them as a truck,and the camper body a "Payload".But this is what they are doing to anything over 3500 and classing them subject to cof as a "heavy vehicle".So therefor you are paying road tax etc for a heavy vehicle an yet it would never carry the pay load of a heavy vehicle.There certainly needs to be a change in legislation concerning Motorhomes to de-rate them hence they will never carry the manufacture's vgm.I imagine there will be hundreds of members and non members throughout the country who are paying far more than they should on road tax etc,just to own and enjoy our responsible freedom camping.We don't own trucks,we own campers and motorhomes. Even buses need to have a change.Its common sense isn't it?I hope someone who knows about this can push for a change that's well over due.
 #144531  by Zukiwi
 Fri Sep 14, 2018 11:58 pm
William I think that race has been run. And for now at least we're not in the birdcage. I didn't understand your first post but now I think I've got the gist and I very much agree with your sentiment about RUC and vehicle weights. I have a bus with a GVM of 10100kg. Fully loaded on the road it weighs 7500kg. Because of the bands RUC is now calculated in I have to pay for a 12 tonne charge, virtually double what it cost before the changes 5 years ago. Given my advocacy for consideration of the special circumstances of motorhomes (GVM vs actual unvarying maximum weight) and the blow-off I got from ministers and NZTA as well as the absence of any real interest from NZMCA at the time, it's a lost cause.

 #144539  by vansvilla
 Sat Sep 15, 2018 7:32 am
John. I wonder if the appetite for change is there with the new Govt?
It would be interesting to read the Labour Party opposition to the bill and use that as an argument for change.
I have always believed the mechanism to allow for M/homes being charged actual weight exists already.
When your bus was converted so to was the registration status.
Mine changed to the Letter K on the registration label. I had to prove it was a M/home, ie 50% beds, sinks, living area etc before this could be registered as a M/home.
To me that gives the regulators a means of differentiating us from Goods services vehicles.
Now as to the policing of it, simple, we get weighed each 6 months during a COF when on the brake tester. Quite a simple matter for the inspector to see what RUC you are paying for compared to the vehicle weight. Any inconsistency means a Fail and an Audit.
IAW the new rules I applied for an exemption providing weigh bridge certificates etc and were turned down. I was invited to get a Judicial review on the matter. Any savings weren't going to recoup that expense :D
 #144541  by William
 Sat Sep 15, 2018 9:44 am
Our NZTA "In the know" NZMCA officers/members are not interested in pushing for any change.Ive already been down that track with them.There must be hundreds of motorhomes and the likes of members and non members throughout the country who are all trapped into wrongly classed vehicles,all because NZTA dont reconise them for what they are.There needs to be a big change in leglistration to get this fixed.In our life time??.
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