Newbie: Disco 6x6 from Spain

[TD Man]

I agree that there are better ways to achieve the outcomes I am looking for but as Bill has eluded to importing is a hassle and shipping is expensive here.

I am a fitter turner anyway and work for a firm that specializes in pneumatics so air bags are a well supported option and the engineering in other parts of the build is within capabilitys that I have or can draw on.

I would love to just pay the 16k and own one but then I would still have to put a body on it, shorten the chassis, certify it, put air bags under it etc so I reckon by the time I do all that I may as well sort the drive through and use what I have.

The primary wheelbase is quite long but I still need to get 6 people seated so am slightly limited by this.

Hope all this makes sense, more to come

TD

[miketomcat]

Wouldn't it make more sense to use a disco chassis and extend the back/stiffen as necessary than to shorten then extend a 110 chassis.

Mike

[Jamie_grieve]

He's modifying a double cab 110. I'd guess the deeper chassis and different outriggers as well as keeping the same registration would be advantageous. Cutting and shutting a chassis is a fairly straight forward job on a double cab compared to trying to do something that looks right to a Discovery for the sake of one welding job.

TD Man, will it have a ute style body or will you do something with a long wheelbase tub?

The LT 95 option is a good option where you are as there are loads over there but how easy it would be to get something together with two outputs I'm not sure?

By using a P38 axle for the third axle which has the diff on the other side you could keep all Rover parts if it made getting a cert easier? Centre bearing on the middle axle wouldn't be difficult to come up with and would be all the modifications required other than adding suspension mounting points. The P38 uses a panhard rod that might be easier to package?

The Praga and many other trucks use this system and it gives a longer drive shaft between the axles than a driven through diff or avoiding the (potential) weight, height problems and drive shaft angles of a diff mounted through drive. Maybe inventing a separate splitter box from an upside down transfer case using the centre diff from the front output shaft as the input, the rear output going to the second axle and the PTO going to the third axle to give you an interaxle difflock controlled from the cab and saving the use of free wheeling hubs on the rear?

I just mention the interaxle difflock in case you require 'road friendly' suspension and drive trains that don't scrub tyres for certification. To be fair, neither my Volvo or Praga have inter axle diffs and they seem to get on fine without.

[bill van snorkle]

The Australian Army are replacing their 6x6 Perentie Landrovers with 6x6 G wagons.so eventually spare transmissions and components, including the high/Low range PTO will appear at military surplus auctions. Failing that it wouldn't be too difficult for a fitter and turner to make one from a second rear output housing and scrap centre differential. The Perentie PTO has a dog clutch to disconnect drive to the third axle, as does my old drive splitter drop box, but in practice, due to the relatively light weight spread over 4 large tyres, transmission wind up and tyre wear was never an issue so I kept both rear axles permanently engaged.

Defender style body mountings are fairly easy to make to fit the Disco/RangeRover chassis, and seeing as they already have the desired wheelbase, IMO one of these would be easier to deal with than shortening a 110 chassis, where it may be difficult to find 2 points 10" apart where the depth of the box section is the same. The shallower depth of the disco/RRC chassis may offer slight ground clearance advantages also.

[o_teunico]

This is another aproach...tridem!

.

Axles 2 and 4 will be lifted 95% of the time. If the terrain is soft, all three axles will give extra flotation. Need a super reduced turning circle? Lower axle 2 and lift axles 3 and 4.

Making the tridem compact could be possible using narrowed series axles for 2 and 3 and a widened coiler axle. Could be easy with the correct offset reversible wheels, just in the same way as seen in front vs rear axle in twin wheeled vans.

That will give an axle arrangement similar to Nazi tanks.

.

Problem? If you need to take out one wheel from axles 2 or 4, you will need first to take out axle 3´s wheel.

Packing transmissions for 3 axles in so little space is another challenge...

[Josh NZ]

There's a bunch of perenties on trademe currently... Asking big money though!

[bill van snorkle]

There's a bunch of perenties on trademe currently... Asking big money though!

Yes, the vehicles themselves will fetch good money, but the spares are auctioned separately and usually are quite reasonable.

The only real problem I foresee with using the PTO position to drive the 3rd axle is that it won't be possible to fit an underdrive also, and personally I don't consider the overall gear ratio of a standard 110 at 48:1 to be anything like low enough for a serious cross country 6x6 with difflocks and 37" tyres. Hard to believe, but there has been the odd occasion when I thought the 270:1 low low low ratio of my 4x4 LandRover on 36" tyres could have been a tad slower.

[TD Man]

There's a bunch of perenties on trademe currently... Asking big money though!

Yea, 55K was a bit steep for a project truck.

[TD Man]

Yes, the vehicles themselves will fetch good money, but the spares are auctioned separately and usually are quite reasonable.

The only real problem I foresee with using the PTO position to drive the 3rd axle is that it won't be possible to fit an underdrive also, and personally I don't consider the overall gear ratio of a standard 110 at 48:1 to be anything like low enough for a serious cross country 6x6 with difflocks and 37" tyres. Hard to believe, but there has been the odd occasion when I thought the 270:1 low low low ratio of my 4x4 LandRover on 36" tyres could have been a tad slower.

I have a 110 chassis that has been shortened 90" I think, but I don't think I will fit rear foot space if I go that short.

I would like to shorten the hole thing up but the reality is I have a family that enjoy coming 4x4ing so I have to have the seating, I they cant come I can't go so already there's a compromise, but hay, it's not as entertaining by yourself...

TD

[FridgeFreezer]

This is another aproach...tridem!

And that is the answer to which question?

[bill van snorkle]

And that is the answer to which question?

I couldn't work that out either.Especially when O'Teunico mentions axle number 4 !

the 3 axles interlink appears to be how I understood the Berliet 6x6 suspension to be laid out, but certainly couldn't be applied to Sam (TD Man's) project plans.

[o_teunico]

Yes, something inspired in the Berliet. Not any answer, just another idea about multi axle.

Today I have crawled under the Series I hearse, and I have discovered those six bolts under tons of muck and grease. Now I have two diffs for experimenting

[TD Man]

Yes, the vehicles themselves will fetch good money, but the spares are auctioned separately and usually are quite reasonable.

The only real problem I foresee with using the PTO position to drive the 3rd axle is that it won't be possible to fit an underdrive also, and personally I don't consider the overall gear ratio of a standard 110 at 48:1 to be anything like low enough for a serious cross country 6x6 with difflocks and 37" tyres. Hard to believe, but there has been the odd occasion when I thought the 270:1 low low low ratio of my 4x4 LandRover on 36" tyres could have been a tad slower.

270:1, I'm impressed, is that one of your creations?

[bill van snorkle]

270:1, I'm impressed, is that one of your creations?

Yes, I have a hybrid undedrive made by combining the input shaft and output gear from a fairey overdrive with the High/Low range planetary reduction box from a Jeep Quadratrac transfercase. bolted behind a series 2 Landy transfercase and Warner T98 truck 4 speed.

[bill van snorkle]

Yes, something inspired in the Berliet. Not any answer, just another idea about multi axle.

Today I have crawled under the Series I hearse, and I have discovered those six bolts under tons of muck and grease. Now I have two diffs for experimenting

most Landrovers built up to 1971 had diffs with the 6 bolts.

[TD Man]

If you want 6x6 with portals / walking beams, why not start with a 6x6 vehicle on portals, would save a hell of a lot of engineering that you'd then throw away later.

I agree but finding them is the issue here. I have looked on ebay but there must be better places to try.

In NZ you can import a vehicle over 20 years old without any major drama but any newer and there is a ban on it up till 2 years old.

I would look to bring in a Volvo if possible but I don't know what I'm looking at and would need to do some homework.

Our Army use the Pinz 6x6 but no parts are on the open market as yet.

I'd agree with fridge here, get a Volvo C304 if you need a six by six chassis with portal axles. It'll save a lot of time and trauma and would hold it's value better than developing another vehicle so similar.

I'd agree with Bill about a 6x6 not being as ultimately capable as a well developed 4x4 but I'd also add that compared to a 4x4 using a production chassis with standard type suspension then a 6x6 will outperform cross country in most circumstances except speed.

As Bill says, for a 6x6 to really perform it's important to have proper load sharing throughout the whole range of suspension travel. I'd suggest using oversized pipes between the bags to improve reaction time and to avoid one bag being at a higher pressure than the other on bump. That said, even with standard pipework they would be a lot better than coils in the same circumstance.

You could still use the existing land rover suspension but not have a walking beam but just employ a leaf spring in the conventional fashion. This would probably be the simplest and best performing method even above that of the air bags for serious cross country work but not as good for rough gravel tracks and pot holes.

One problem with walking beams other than their huge weight is also that the front wheel becomes unloaded climbing and they bounce and the opposite on braking. A good modern comparison would be a Moxy / Komatsu dumper with a walking beam versus a Volvo with a balance beam and A frames and panhards. The Volvo outperforms at speed and climbing, the Moxy will crawl through a bit of bad ground better.

I had a wee look for the 'Scammel constructor' Land Rover, it was amazing. Anyone got a link? It would be worth looking at.

Suspension is the big one, I have contemplated using pneumatic cylinders to replace the springs, this would mean load sharing, ride hight adjustment, the ability to lift an axle, tilt the cab or lock the cylinders so the hold the same position to reduce body roll on the road. The only issue would be seal life but I would probably only drive it twice a month.

[TD Man]

Yes, I have a hybrid undedrive made by combining the input shaft and output gear from a fairey overdrive with the High/Low range planetary reduction box from a Jeep Quadratrac transfercase. bolted behind a series 2 Landy transfercase and Warner T98 truck 4 speed.

Nice work mate!

[TD Man]

Ok, So drive-line.

I am thinking I would like to split the drive after the hand brake and run a shaft to the rear axle right of the chassis, I will be on the farm on sunday and will have a look then as to the reality of this.

I will also check the other landy and see if I can use its chassis as it is already shortened and has a cert, I just need to check the room for fitting a body on it.

Bill, I was thinking of using a chain drive box as opposed to the gear drive box you built, what are your thoughts on this and the position?

Thanks,

TD

[bill van snorkle]

Ok, So drive-line.

I am thinking I would like to split the drive after the hand brake and run a shaft to the rear axle right of the chassis, I will be on the farm on sunday and will have a look then as to the reality of this.

I will also check the other landy and see if I can use its chassis as it is already shortened and has a cert, I just need to check the room for fitting a body on it.

Bill, I was thinking of using a chain drive box as opposed to the gear drive box you built, what are your thoughts on this and the position?

Thanks,

TD

TD, there is a company over here called 6x6 Australia that have Morse Chain splitter boxes.However, if you are prepared to make your own casing, A Nissan GQ/GU transfer case Chain and sprockets are proven and tend to last very well, and the transmissions are cheap as chips over here because they are so long lived. However, mounting the splitter box within the 100"wheelbase will eat into the length of the propshaft to the leading rear axle which it turn may restrict the amount of articulation that you can build into the suspension. If you mount the splitter box directly to the leading diff it doesn't shorten shorten the propshaft by much, but in that location, overheating of the chain seems to have been a fairly common experience over here with our generally longer distances and hotter climate.The Icelanders apparently use pinion mounted chain drive splitters successfully in their climate though.

For twice a month usage chaindrive would probably be easier and cheaper for you to make up and likely last many years. Incidently, At the LandRover Club 4Wd show last weekend, a bloke had 2 6x6 Volvo's that he imported from Sweden on display. One was for sale at $40,000. He's dreaming I reckon ! Aside from Volvo's portal axles, I'm not convinced that the remainder of the vehicle is all that desirable. The Chassis is dead straight over it's length, so for a passenger vehicle it's always going to be a pain to get in and out of. The gearbox and transfercase doesn't provide anything exciting in the way of gear ratio's, and would be better replaced with an R380/lT230 anyway, and the engine is nothing particularly special either.They also lack power steering and disc brakes. Be better taking a trip to Malaysia to see if you can dig up a set of axles and slip them under a LandRover.

[TD Man]

TD, there is a company over here called 6x6 Australia that have Morse Chain splitter boxes.However, if you are prepared to make your own casing, A Nissan GQ/GU transfer case Chain and sprockets are proven and tend to last very well, and the transmissions are cheap as chips over here because they are so long lived. However, mounting the splitter box within the 100"wheelbase will eat into the length of the propshaft to the leading rear axle which it turn may restrict the amount of articulation that you can build into the suspension. If you mount the splitter box directly to the leading diff it doesn't shorten shorten the propshaft by much, but in that location, overheating of the chain seems to have been a fairly common experience over here with our generally longer distances and hotter climate.The Icelanders apparently use pinion mounted chain drive splitters successfully in their climate though.

For twice a month usage chaindrive would probably be easier and cheaper for you to make up and likely last many years. Incidently, At the LandRover Club 4Wd show last weekend, a bloke had 2 6x6 Volvo's that he imported from Sweden on display. One was for sale at $40,000. He's dreaming I reckon ! Aside from Volvo's portal axles, I'm not convinced that the remainder of the vehicle is all that desirable. The Chassis is dead straight over it's length, so for a passenger vehicle it's always going to be a pain to get in and out of. The gearbox and transfercase doesn't provide anything exciting in the way of gear ratio's, and would be better replaced with an R380/lT230 anyway, and the engine is nothing particularly special either.They also lack power steering and disc brakes. Be better taking a trip to Malaysia to see if you can dig up a set of axles and slip them under a LandRover.

Thanks Bill,

That is what I was wondering but did not know, I will (and have) looked into the axles but again it seems to be a right place right time sort of thing with some of this. I will keep looking and have a friend with a Nissan he is wrecking so will look into that to.

TD

[o_teunico]

Suspension is the big one, I have contemplated using pneumatic cylinders to replace the springs, this would mean load sharing

Here some good detailed pictures of the 6x6 perentie arrangement, with leafs and rocker. Bill, was something like this what you used in your 6x6?

[bill van snorkle]

O'Teunico, The Perentie rear suspension was designed for load carrying over normal 4wd terrain. It has very little articulation and the long underslung leaf springs compromise under axle ground clearance. In other words, It is not a design that a serious cross country vehicle builder would consider, and NO it is nothing like my old 6x6 rear bogie suspension. My suspension was very similar to that of the Volvo on page 6, with the exception that the cross beam that the spring pivots and control arms were bolted to, was itself connected to the chassis via a 4 link arrangement that the axles to droop further. The effectiveness of this double articulating design was only possible due to the relatively long interaxle propshaft that linked the twin drop boxes(one for each rear axle).

[FridgeFreezer]

This of any interest? Volvo 6x6 rear end.

[Jamie_grieve]

Great picture of the Perentie, first time I've seen it. If they went to the trouble of putting a rocker in, I can't for the life of me understand why they didn't use a conventional system like the that of the Volvo in Fridges picture which is the same as nearly every other 6x6 on the planet. It would have been cheaper, lighter, more durable, able to carry the weight with more wheel travel and better load sharing on more severe terrain. It would have had more clearance....the list goes on...They must have had a good reason for it?

It does look like it would be really easy to modify to a conventional arrangement.

[bill van snorkle]

The propshaft to the rearmost axle is a two piece affair with a centre support shaft on the chassis above the leading axle and a short double cardan jointed shaft down to the rearmost differential.On the couple of civilian versions of the Perentie's that I have worked on, these double cardan shafts had been replaced at around 45,000 Kilometres. why they didn't mount the centre support shaft on the leading rear axle as traditionally done has got me baffled. It would have lasted much longer and allowed more articulation.