25 replies to this topic

[Zook]

So I'm about to buy this one tonner. It's got some cool mods that need to be engineered, one being the 6 wheel conversion. I have been researching it while talking to Byron but so far we're drawing blanks on where, when and how the conversion from a standard 4 wheeler was done. I'm pretty sure they could be done from new but it was not done by GMH. Does anyone have any history on these things?
Cheers

Edited by Zook, 22 August 2020 - 07:10 PM.

[arrimar]

Is it the HQ one on Carsales? Guy says he has had it 20 years. Maybe he could fill in some gaps.

[Zook]

No, this one is not advertised but it might be worth checking in with him, thanks.

[WhiteA9XS]

I had a WB 6 wheeler in the eighties which I used for country newspaper and airfreight runs , originally a 202 and later 308 , used to load it to 2 tons , no other small trucks were as quick as the freight was time critical so they were perfect .
, they were a lazy axle set up with extended chassis , not sure who did the conversions but the dealers would organise it for you .

[S pack]

Perhaps old street machine magazines and the like might have advertisements for those conversions.

[Bigfella237]

Somebody did a bogie drive one of these for Summernats burnouts many years ago, from memory I think it was some transmission/diff business' work ute, I can't remember their name though.

 

I'd be interested to see how they set up the diffs and whether they are doing them as a kit or similar. Anyone have pics or even remember their business name?

Edited by Bigfella237, 23 August 2020 - 11:22 AM.

[yel327]

Just a Dana pass through middle axle.

[Zook]

I've contacted Street Machine asking if they have any articles, thanks Dave.
Yeah I've heard you can put two tons in them and one of the things we're trying to certify is the actual capacity. It has a semi-lazy axle; it's not driven but it is braked. The rest of the driveline is VS SS.

[rodomo]

Have a l@@k here http://stretchpack.com.au/ it says originally developed by Hayman Reese...……..the tow bar mob.

[Rockoz]

Brickie friend of mine had a HQ based one in the 80s.

He loved it apart from one problem he had.

On uphill sharp turns, like Bulli Pass, the lazy axle took weight of the driven axle.

He took about 4 goes to get around that corner once.

If you remembered to drive it properly you could reduce the wheelspin.

An LSD would have solved the issues no doubt.

He liked it because it was nicer to drive than the F150 and F250 that were also in his fleet.

He sold it though not long after having the difficulty and bought an F100.

 

Cheers

 

Rob

[yel327]

The biggest hassle getting it rated for 2 tonnes today will be the maximum front axle loading. The rear obviously increases but unless it loaded like a Ute with an Elephant on the back, adding 2 tonnes over the rear axles has to see some increase in the front axle loading. Maybe it can be loaded to keep the front below the maximum rated capacity, but I can also see braking bias issues under that situation. I’ll get you the original front and rear axle loadings. Remember GMH added significant capacity to certain parts of the vehicle to get to 2660kg GVW, namely heat treated front stubs, fully welded 14x6 wheels, Salisbury rear axle with far wider bearing retainers, heavy duty front and rear springs and heavy duty front and rear uni joints plus a big tailshaft. Even with these the chassis still cracked badly around the lower control arm welds and around the “shock tower”. So by giving it a GVW of 3760kg I reckon it’d be a challenge to load it right and keep the front axle weight below the original maximum. Not sure how they rated them back in the 70’s when converted.

[Zook]

Hi Rodomo, nah it's not one of those. They look to have a bolt on axle and the extension from the rear of the chassis rails. Mine looks to be extended from just behind he cab and everything is properly welded including fish plates. Need to pick it up and get some photos! I also found a crowd (Em-Care) who used to do it as part of creating an ambulance from the one tonner variant.

 

Hi Rob, I can see how that would be a problem. The guy who rebuilt it with the new driveline says its got an LSD in it so that should help.

 

It's also a tipper, rad.

 

Edit. Thanks Byron, having the load ratings would be very helpful in determining what we can go to. It's not that I want to go to 2T but we are looking to go higher than the GVM that is currently listed (2660Kg) obviously. Good to know that all that other stuff is uprated and I'll pass that to the engineer. Unfortunately we haven't been able to find an uprated GVM placard. The point about brake bias has been considered and I'm going to add adjusters between each of the three axles to get that right. It will need to be brake tested so doing this will help passing that, especially since we need to test it loaded to whatever GVM we arrive at!

Edited by Zook, 23 August 2020 - 05:01 PM.

[yel327]

See if you can get a look under an original Overlander and see what was done from where the new gearbox crossmember is all the way forward to where the back of the front leaf springs go. These were 2800kg or so, and had far bigger rear leafs and front & rear axles. Plus huge brakes. I remember when I was building my house and I had to get a pallet of bricks on my HZ Overlander, as my Daihatsu tipper was out of action with a load of sand and gravel. With about 1.5 tonnes on the back and over the rear axle I remember being amazed how much was actually on the front axle, the front was almost on the bump stops.

[arrimar]

We had Landcruiser 6 wheelers at one place I worked. Forever spinning the inside wheel when unladen. Pretty rough ride too.

[rodomo]

Were they from Four Wheel Drive Hire? They had a few back in the day.

[RallyRed]

Common problem...all hire vehicles seem to spin wheels

[yel327]

Here are HZ commercial weights. These are the standard vehicle, so for the cab-chassis that will be 3.3L, 3spd and salisbury rear axle with front disc brakes. This is why only 2600kg is shown for the GVW. V8 is 2660kg. The top line of figures on each row is lbs, bottom line is kg.

 

The cab-chassis Curb weight (full of fuel) is 1287kg as you can see this leaves you 1313kg for a tray plus load, so only allows for a 313kg of tray leaving you with 1 tonne of carrying capacity which obviously includes people and other stuff like towbar and options such as A/C, power steering, L31, M41 etc. Note that on the second file the V8 cab chassis GVW is 2660kg but its Curb is 1359kg which is 72kg extra for the 4.2L V8 plus whatever extra stuff the V8 gets, which means you have already lost 12kg from your GVW as the V8 cab-chassis is only 60kg higher in GVW than the 6cyl. Add on L31, M41 (100kg over standard), A/C (43kg), bucket seats (6kg), power steering (9kg), towbar (12kg) and with a decent tray you can really soon see your "1-tonner" has suddenly become a "900kg" without accounting for driver.

 

You can also see that there is no max and min front axle loadings for the V8. So using the 6cyl figures, you can only put 1000kg on the front axle out of 2600kg, and on top of this you cannot have less than 757kg on the front axle when the vehicle is fully loaded at 2600kg. So by upping the GVW to 3600kg with an extra rear axle, sure you can probably now fit 1792kg+1000kg directly over the pair of rear axles but that leaves you with only 808kg on the front axle which is in between the minimum and maximum allowable. However if you move that 2000kg forward a fraction to distribute the load better, it wouldn't take much at all to suddenly see in excess of 1000kg on the front axle. What I'm getting at is properly loaded with 1 tonne and with a light alloy tray the front suspension of a HZ cab-chassis is at or near full capacity. By converting it to a "2 tonner" and distributing the load you'd have to be really carefully that very little of that 2 tonne is loaded biased towards the front axle or it will be overloaded as the front axle has not been upgraded. Then loading in this way you may find the car is not all that stable as the back would be very heavy and the front would be light in comparison. The Engineer you are talking to will be far more versed in this than me though! 

 

 HZ commercials weights.pdf   90.91K   3 downloads

 

 HZ V8 weights.pdf   55.54K   3 downloads

[arrimar]

Were they from Four Wheel Drive Hire? They had a few back in the day.

No I think the owner had them done from new.

[Bigfella237]

 ~ I also found a crowd (Em-Care) who used to do it as part of creating an ambulance from the one tonner variant. ~

 

 

 ~ it will be overloaded as the front axle has not been upgraded. ~

Just keep adding axles...

 

[Statler]

My painter is about to start work on a 6 wheel Statesman ute. 

My God it's fugly !

[Rockoz]

Byron, isnt the lever from the chassis to the brake system the solution to brake bias with a load on it?

I was told that is what it was for.

 

Cheers

 

Rob

[yel327]

Not all had it, especially the 4 wheel drum examples.

[Zook]

We bought it today and so are pretty excited to be bringing it home. Our engineer is on board which is good cos there's a bit for him to do. He's very thorough btw. Certification will include 6 wheel conversion, VX LS1 and gearbox, VS diff, 15" wheels, seats, Hoppers Stoppers.

[yel327]

You may have to use a VY-VZ 1-tonner diff as a VS one won’t be built for the load. Ask your Engineer to be sure. Same with 15” wheels, hard to find 15” wheels rated to 750kg that aren’t Sunraysia style, most are 690kg. I looked everywhere for my box trailer which is 1540kg ATM / 1400kg GTM and had to use 15x7 Holden VY-VZ cab-chassis rims.

[Rainman]

Thought some mentioned    Brazier Mobility - Les Brazier Special Vehicles in Adelaide . Not sure but you can find there number in Google Search. Ray