Sunday, Mar 06, 2011 at 23:28
John P
There is a whole bunch of stuff that is taken into account re computing GVM'S.
In October 2005 I had the GVM of my 1997 75 series Troopy re-engineered from 3100kgs to 3495kgs.
The engineering certificate shows:
Original Specs 1400kgs front axle, 2000kgs rear axle - GCVM 6350kgs
and
Re-eng'd Specs. 1400kgs front axle, 2500kgs rear axle - GCVM 6350kgs
The maximum a 75 series Toyota GVM can be upgraded to is 3500kgs before you have to add a ridiculous amount of emission control gear, plus arduous testing programme, that makes it totally cost prohibitive to do so. The Engineer said at the time that it would be cheaper to buy two new Troopys.
With this in mind he took the upgrade to 3495kgs so that it was just under the magical 3500kg mark so that there would be no arguments.
You will notice that the GCVM did not change during the aforementioned exercise, and the GVM only increased to that allowable under then current regulations for my vehicle, not that by adding the axles together.
However what did also change was the Tyre Placard which increased tyre size specs a tad.
Engineering computations - The Engineer had a book the size of the old Encyclopaedia Britannica, which had all the engineering specs for the original vehicle build ( Brakes, springs, shackles, Shockers, wheels, tyres, axles, chassis etc etc) which were entered into a computer program along with all his vehicle
test results, and bingo there you have it.
DD
AnswerID:
447526
Follow Up By: Ozhumvee - Monday, Mar 07, 2011 at 08:03
Monday, Mar 07, 2011 at 08:03
The ultimate limit is the combined capacity of the axles but as DD shows if done correctly other criteria come into it which may result in a lower limit.
It always amazes me that people expect to be able carry far more weight in a vehicle than the manufacturer who designed it and spent millions doing so and decided on the original figures expects it to. The more weight you carry the faster components wear out.
Remember also that few manufacturers expect you to want to carry or tow at the stated limits for more than a certain percentage of the time so operating the vehicle at its maximum carrying capacity will lead to a shortened life.
I suspect that many have the wrong vehicle for their situation and should be looking at small trucks to tow and carry their loads.
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Follow Up By: Member - Phil G (SA) - Tuesday, Mar 08, 2011 at 09:47
Tuesday, Mar 08, 2011 at 09:47
DD,
In which State did you get the engineering done?
I haven't heard of a 3,500kg limit before. In most States, the expensive rego and increased inspections come in at 4,500kgs.
And I'm amazed an Engineer can override Toyota's specs and upgrade the rear axle load by 500kgs!
Cheers
phil
FollowupID:
719962