Tare weight of XT cab/chassis?

Planning to build a light weight (under 4.5T) camper.
Anyone know the tare/empty weight of an standard XT cab/chassis?
Cheers,
Peter

Hi Peter,
I can't answer your question precisely, I am sure someone will, but I think it was about 2.9 tons with bare chassis. Mine weighed in at about 4.3 tons finished, but no luggage, tools or water. I have a lot of heavy things that could be deleted, and I am thinking of going the same way as you - light weight lest we have our heavy licenses taken off us for being old!

Oh, and I have 6 alloy wheels that saved about 200 kgs.

Peter

I am sure you realise that the under 4.5 ton Oka is merely an administrative exercise. There is no Oka in Australia that goes under this with a camper body fully equipped with supplies, equipment ,fuel and water for an extended trip.

The best you will do is get a vehicle light enough to undercut the registration limit basically empty with probably only one tank of fuel and no supplies or water. The 65 kg nominal passenger weight for registration helps the cause. This is the point of the exercise and I think your plan is well worth the effort to avoid yearly truck inspections, reduced registration fees and to have car only drivers.

It is a very interesting exercise and quite satisfying trying to shave kilograms. I had to struggle but managed to do it.

Have fun.

Lang.

Thanks Paul, and yes Lang, I know I can not achieve like for like and simply get rid of a ton or more, but I reckon I can get to the point where it can be a question of "how much water", particularly if the emphasis on weight reduction is "all consuming" and starts with a full attack on the cab chassis including roof, door skins, bumper bar, engine cover, seats, glove box lids...there are a lot of 500gm savings to be made I reckon.
What can you include/not include in the 4500kg Lang?
Cheers,
Peter

Peter

The engineer who gives you the blue plate is key to everything. Ask around and find one who is "reasonable". The hot rod blokes, for obvious reasons only deal with "reasonable" engineers, try them for names.

You can do what you like to get it under the weight but it must be practical. If you say "I will only have one person and half a tank of fuel and no bedding" even a reasonable engineer would say it is not fair dinkum.

For instance I have 4 water tanks totaling 200 litres but my engineer said ""80 litres is the standard motor home water tank, of course you will only be filling the other tanks for off road desert expeditions, won't you?" and "I see you have a standard fuel tank and a second reserve long range tank for cross country expeditions only"

We have 4 certified seats and he mentioned we may have to reduce our 80 litres of official water with extra people.

None of these provisos appeared on the certification form or blue plate but he was covering his bum by telling you the restrictions, knowing full well they meant nothing in real life,

Lang

Thanks Lang. I have a good engineer, I just hope he does not retire on me
Plastic rotomoulded fuel tanks are the go if they are approvable. I have 2 inside the chassis rails now, but I am not sure about replacing the standard ones outside the chassis rails yet.
When I wanted our rear side facing seats approved for passengers, I suggested that I would need to remove the table between them when they were occupied because the "rules" specifically required that. His response was "If you did everything strictly according to the rules, you would not need me." The table is still there and the seats are approved.
I also have an approved child restraint that allows a kid to sit on top of the engine hatch. That was separately approved by 2 engineers, one in Queensland and mine in SA.
Cheers,
Peter

I vaguely remember reading somewhere that a single cab with bare chassis came in at around 2.9t too.

Peter

When I built my body (See OKA #200 on this forum) I copied the original bus lines but reduced the thickness of all the box sections and sheeting by 50% effectively saving half the weight. It is more than strong enough with no cracking after lots of long distance trips. All the panels have insulation and there is no sign of drumming or oil-canning'

My fibre glass pop top is human lift (with gas struts) avoiding heavy electric motors and screw jacks. It is extremely light and although it does flex on rough roads it has not cracked anywhere.

I am sure the alloy wheels helped in a major way to meet the weight limit.

I left the heavy ROPS construction for the front cab for safety but mostly because it was just too much work to replace.

Lang

We looked at buying one of those fancy vehicles made up a bit north of Brisbane that were registered under some shonky deal because they weighed 50kg under the 4.5 tonne limit.

Apart from the very rough ride on standard bitumen suburban roads despite their fancy suspension engineering, I asked how it could get on the road legally given it had to be all but empty to comply with registration weight restrictions. He said it was easy - just drive out a bit and then add water, copilot, fuel, tools and food. I asked where in Australia can you legally drive an overweight vehicle and got a BS answer so that was the end of that sales enquiry.

Lang wrote: I left the heavy ROPS construction for the front cab for safety but mostly because it was just too much work to replace.

When I built #196, I asked the factory about the roof panel and was assured that it was not part of the ROPS structure. I expect that also applies to a lot/most of the other sheet metal in the cab.

Tony, I have always advocated that a 4WD expedition vehicle under 4.5T was a pipe dream in reality.
Now I will try and build one.
Cheers,
Peter

Like most things Tony, if you want it right, you are best to do it yourself - as you did on your Oka. At one stage I think you were talking of glueing the panel straight to the chassis of the Oka - in hindsight, that is a great idea, or at least an offshoot of that idea. On mine it would have saved 200 Kgs - the weight of the sub-chassis. Overall height would have been reduced by 100mm, not much but it helps.
You do wonder how they got that past rego......

Peter, I am convinced it can be done. As I wrote, mine weighed in at 4.3 tons - just my rear veranda and the front skylight take 100 kilos, my 2mm steel side boxes weigh close to 60 kilos each, superficial body work around the rear another 50 kilos - it goes on and on. I used 3mm aluminium to join the panels, inside and out, but I am sure 1.6mm ally would also have been fine. My drawers are all heavy timber, not light plastic like yours, another waste of weight in mine, another 30 kilos could be saved going LiFePO4 batteries, etc etc. It will be an interesting exercise.

Peter

I think you are correct in assuming no sheet panel comes into ROPS calculations. I am sure you could strip it all off the cab and still meet the specs with the heavy frame in skeleton form.

I wished I had replaced the cab roof because it took ages to chase down all the water entry points on seams because once inside, the water tracks along the path of least resistance. A persistent leak on my right knee from behind the sun visor was eventually tracked to a seam gap above the passenger side top corner.

Lang

With #196, the cab roof is the base of the bed, so it is also flat instead of sloped up to the back. That did not raise any eyebrows with the engineer.
The new one will probably have a raising bed at the rear over the seating & table rather than a bed over (which we love) and I will probably make the new cab roof flat also (made from sandwich panel) and put an aluminium pack rack directly on top of it (with no floor of its own) with tube scrub bars to the top of the full height "box" which will not have a pop top.

And, yes, I am planning to glue the glass reinforced floor of the box directly to the chassis without any steel. Might have to add some safety chains to satisfy the engineer.
They are some of the thoughts so far.

This is not going to be a short term build. I expect to take a year to work on the cab chassis alone.
Cheers,
Peter

Hi Peter, I have a weight figure from 2008 for my LT with no tray.(so cab chassis)
Front 2340 (I have a heavy bull bar and angle under neath)
Rear 900
Total 3240

Cheers

Thanks Ewart. That is 200kg greater than the nominal for an XT.

A few thoughts on some different weight saving possibilities....
Fibreglass rally style seat shells in fixed positions. They weigh about 10kg each.
Replace motor cover hatch with fibre glass sandwich panel (about 6kg/M2).
Sun visor an extension of the flat roof panel from the same material.
Aluminium exhaust terminating in front of the rear wheel.
HDPE mud flaps (very successful on #196).
Lithium crank battery, no battery tray.

Some that need some EXTRA research.
Aluminium or carbon fibre drive shafts. Need to check the racing/rally boys.
Parabolic springs. Existing spring packs weigh in excess of 250kg. Probably custom size and no one in Australia makes them. Anyone have any info? EDIT. Carbon fibre springs have also been made for trucks.
Alternatively, a 2 leaf only pack and air bags.
Alternative transmission/T.C options???
Cheers,
Peter

Peter

You are really serious about this project. You did not tell us you had won Lotto.

The alloy visor being produced by Nugget on the forum is a beauty less than half the original weight. I think you saw mine at Lake Cargelligo

Lang

I have also wondered about aluminium composites - much lighter than the usual fibre glass sandwich panels, and much thinner. Obviously the insulation properties would be poor, but there are other lightweight insulating materials available.

I am hoping that the more complex (read expensive) actions such as lightweight springs won't be necessary - besides, the standard suspension works SO well that I would be nervous about changing anything there. What other cab-over vehicle is comfortable without the need for air sprung seats?

Of course some of us have the penalty of a couple of hundred extra kilograms for an extra two cylinders......might have to be a trade-off in the size of the wine cellar.......no no, only joking!

Thanks Lang, No lotto win I plan on taking 5 years for this build project so completion coincides with the likely loss of my heavy license, so there is time to consider some more radical options. Many will be rejected at the end of the day, but a win now and again would be good.

Yes the aluminium sun visor is a vast improvement, no question, but since I will be replacing the cab roof with a piece of sandwich panel, I can simply make it longer, a bit like our bed-over extension. Total extra weight would be about 6kg (500 x 1900 x 6kg/m2 plus some edge strip). It would also be a 500mm x 1900mm extension to the cab roof rack rack floor where I hope to put spares, depending on weight distribution.

Thanks Paul. My experience is with the FRP/urethane composites and they have given spectacular performance in #196 for 16 years of serious work, so I need to be reminded about the other alternatives, because each has its strengths. I should keep the aluminium versions in mind, particularly for interior applications where skin toughness is less of a requirement.

Please keep the criticism and ideas coming and I will keep sharing what works and what doesn't.
Cheers,
Peter