Newbie: Disco 6x6 from Spain

[mickeyw]

Looks like something Lady Penelope should be driving

[bill van snorkle]

Teunico,I think you may need to emigrate to the USA or Russia to have a chance of actually being able to use your creation .

The regulations in Spain,and to a lesser extent the UK and even here in OZ seemed to have evolved to stifle individual creativity.

I did originally consider cutting the side walls out of tractor tyres for tracks to surround the rear bogie wheels on my old 6x6, but didn't think they would last very long before tearing.Might be ok for belly tracks though with steel belted radials.

Your revised drawing is fairly close to what I had in mind.Anyone browsing this thread should be aware that you have intentionally exagerrated the differential offsets for clarity.

The toothed belt drive should work ok. Is that an overload clutch mechanism inside the right side pulley hub? Might be usefull to relieve transmission windup between the diffs.

Regardless of whether gears, chains or belts are used, they really should be enclosed in a water/ mud proof housing and to prevent sticks etc from getting between a pulley and belt.

Morse chain, as used in Rangerover borg warner transfercases or similar, for some reason (possibly heat) have a very high wear and failure rate when used for 6x6 pinion mounted drop boxes. A couple of firms here in OZ have and still do use them for converting Toyota LandCruisers and Nissan Patrols into 6x6 offroad tour buses, fire engines etc, but the chains/sprockets appear to be consumable items requiring periodic replacement. Then there is the additional problem of incorporating disconnects to isolate drive to just one differential for road use.

I believe gear drive is still the most durable long term solution.Series 1,2 and 2 a diffs have a 6 bolt flange on the front of the pinion housings, on to which the drop boxes can be easily bolted, and the transfercase gears are already made for dog clutches to disconnect the drive.

Thanks for the tips on conserving bandwidth Fridge.Every little saving helps.

[bill van snorkle]

Incidently, if anyone is wondering why my old 6x6 LandRover no longer survives, the reason was that I ran out of crown wheels and pinions. The reverse mounting of the rear bogie differentials meant that the diffs were driving on the 'coast' side of the gear teeth, which is significantly weaker than when driving on the correct side.That vehicle was built and used well before there was a strong aftermarket industry, supplying reverse cut crownwheels and pinions, difflocks etc.The installation of a pair of Ashcroft or KAM reverse cut ring and pinion sets would make that vehicle much more successful, but alas it's too late, as the remains of the old truck was consumed in the bushfires we had back in Feb 2009.

[Landy-Novice]

what you trying to find out about 6x6 land rovers?? i have sandringham 6

got any more pictures? and/or could you update your topic?

[Nigelw]

Yuck, horible looking thing!!!

Something better?

[bill van snorkle]

STOP PRESS! BREAKING NEWS ETC!
Bloody hell ! I was only going to visit this forum for a few days after a long absense. Caught sight of this 6x6 thread, and now I can't let go. Anyway, the breaking news is that I am on the cusp of working out how to bolt an actual series LandRover transfercase onto a diff pinion housing and converting it to a 1:1 ratio vs the normal 1.148:1.Anyone intimately familiar with Series transfercases should be able to follow my explaination.If availability of Series T/cases is similar to over here (free in many instances) doing it this way will greatly reduce the cost and labor involved with making a dedicated drop box for the job. I've dug out an old t/case and pinion housing and it appears quite easy to do by making a steel adaptor plate that replicates the shape and bolt pattern of the back mounting face of a Series gearbox, with the additional bolt pattern to match the 6 bolt flange of early series pinion housing,but offset about 6mm to accomodate the larger diameter of the high range gear, which would be bored out and have a pinion flange welded to it to match the pinion shaft.
Well that's the simple explaination, but because the transfercase at 150mm wide (face to face) is more than twice as wide as my original drop box, that eats into propshaft length.So I have decided that to win back some of this length, the webbing of the pinion housing can be machined back and a 210mm diameter steel mounting flange, containing the t/case mounting bolt pattern is then welded to the machined face, similar to how Ashcroft and Foley through drive pinion housings are modified. The principal once again as with my 6x6 is for the vehicles main transfercase propshaft to drive into the thru shaft of the leading differential drop box to the rearmost differential. The train of 3 gears in the drop box sends the drive down to the pinion of the differential, and the drive can be disconnected via the dog clutch on the thru shaft.
As far as I can determin at this stage, a milling machine would not be required. All machining can be done on a centre lathe capable of swinging the 125mm radius dimension of the diff pinion housing.
The transfer case for this application would not have the bulky heavy front wheel drive housing,shaft etc fitted to it.The low range slider gear spur gear can also be deleted and replaced with a PTO dog clutch. The high range gear that is fitted to the diff pinion is supported by the pinion bearings themselves. No additional bearing carriers are required in the casing, just the correct shaft spacing has to be accomodated.

BTW, this is just a hypothetical 'Vapor' project for me. I no longer possess a lathe and don't really have the energy to do another build. I 'm just putting my ideas out there.

[bill van snorkle]

This could be cheap and work properly

Blue:pulley

Green:belt

Red:propshaft

3rd to 4th proshaft will be located left hand for easy belt tensioning and diff clearence when on full articulation.

Rearmost axle pointing rearward as in Bill´s 6x6 for longer propshaft.

Teunico.I assume that you intend to turn the rearmost diff upside down inside the banjo housing to correct the direction of rotation? The actual diff offset of 160mm measured between the pinion and A frame ball joint is much more agressive than for series axles, so I'm not sure that turning the diffs back to front with the offset to the left would work well with drop boxes made from Series t/cases, because the distance between input and output shafts is only 224mm, where it would really need to be in the order of 350mm to realign the t/case output shaft with the drop box input shaft.

Could we get some idea of desired wheelbase, front to leading rear axle to calculate propshaft lengths, u joint angles and potential suspension travel limits? For example, I have just measured the rear propshaft on a rangerover at 79cm cross to cross.Shortening the wheelbase down to 80 inches will make the shaft only 29cm long. Even with 45 degree universal joints and the propshaft level in the static position that will only allow the leading axle to rise and drop a total of about 50cm.That is only 25cm up 25 down.RangeRover wide angle propshafts only go to about 27 degrees, so you would be looking at a lot less travel with them.

That was the reason why I reversed both rear diffs on my 6x6 and used a drop box on each, and that was to have relatively long propshafts with a short wheelbase.

[Nigelw]

is there no way to use a rockwell type design and put the rear most diff nose up? I ask as then a PTO could go to a second box and then to the rear axle giving a much longer prop length?

[o_teunico]

My brother is a lathe/milling machine technician. He worked in several companies in the Basque Country and also at the GKN Driveline factory in Vigo. He works now in a petrol station and unfortunately does not have lathe or mill at home

[bill van snorkle]

is there no way to use a rockwell type design and put the rear most diff nose up? I ask as then a PTO could go to a second box and then to the rear axle giving a much longer prop length?

To make a Rover type diff into a Rockwell style would require a 90 degree drive bolted to the vertical pinion that would raise the propshaft height excessively. Would be easier to get hold of some Ford M151 jeep diff axle assemblies as used on the 8x8 Willys wagon .

[o_teunico]

Webby, it will be grat if you could post some info about everydady driving a 6x6: tyre wear/wind up, braking, turning circle, ubdersteering at high speeds...

You could post it here http://forums.lr4x4.com/index.php?showtopic=81152

[bill van snorkle]

It's been an interesting thread, and certainly got my long dormant grey matter working again.And as much as I would love to see this build go ahead, I have to be brutally realistic Teunico. Taking everything into consideration, Spanish modification restrictions, unsuitable base chassis, lack of access to a lathe, together with limited finances to farm out machining work etc and a long list of additional excetras, with the best will and enthusiasm in the world, I doubt this project could be a viable proposition. Certainly not in Spain.To even have a hope of getting a 6 wheeled LandRover approved in Spain, I think you need to abandon the Disco chassis and body, and start with one that you won't have to cut up in order to make space for the 3rd axle within the parameters of a compact package. The series one 107 pick up chassis is what you should be starting with. The rear bogie suspension should be the centrally pivoted inverted leaf spring style with 6 control rods as you have shown on post number 53.. No upper A frames, as these will get in the way of propshafts and drop boxes.

Lateral location of the axles is through the inverted spring pivots. Forget the 4th axle under the belly and fit your track arrangement there. Once you have all that built, you can work out how to fit the disco body on top of it all. Failing that, A series 2/3 body is much easier to rearrange to fit.Series 1 pickup body even easier.

[bill van snorkle]

Ok, for the 3 or 4 people in the universe that might still be interested, i have done some calculations based on measuring up my RangeRover 100'' without moving engine/transmission forward. It should be noted that reversing the diff adds 39cm to the length of the primary propshaft .That is an increase from 29cm for 200cm(80'') wheelbase,out to 68cm.

Axle or bogie articulation in this case, unlike for a 4x4 vehicle is measured with both rear axle housings parrallel with each other in the horizontal plane.Actual inter wheel articulation can be significantly higher.

To shorten the wheelbase down to 80'' (200cm) and by turning both rear axles back to front and mounting a modified series transfercase to each pinion, with an axle spread of 40''(100cm), both primary and secondary propshafts would be

68cm long from ujoint cross to cross. With 27 degree range rover wide angle propshaft joints, this will allow interaxle articulation of 66 cm (26.6")total. With special 45 degree joints this can be increased to around 95cm(38") total, dependant on kickup height of chassis rails.

Last bit of detail for now= bottom rear corner of drop box will protrude beyond radius of tyres under 29 inches diameter.

[FridgeFreezer]

I realise the conversation has moved on a little but here's some pics of the shortened 6x6 Volvo & drivetrain:





















Also, the Volvo method for extracting drive from the rear, there is a gear on the diff input pinion where the 6x6 takeoff stub bolts to:



And the suspension & drivetrain layout:

[bill van snorkle]

I realise the conversation has moved on a little but here's some pics of the shortened 6x6 Volvo & drivetrain:

Also, the Volvo method for extracting drive from the rear, there is a gear on the diff input pinion where the 6x6 takeoff stub bolts to:

And the suspension & drivetrain layout:

ThankYou for posting that Fridge. I have never actually seen the undersides of a 306 before. only bastardised axle assemblies we got from Malaysia,minus the PTO for 3rd axle.

The rear bogie suspension is fairly close to how mine was set up.

Despite what I posted earlier,about not having the energy for yet another build, I did a 'stocktake' yesterday, of surviving components from my old 6x6, plus a few other bits and pieces I have gathered over the years. I could actually build this thing that I've been hypothesising about on this thread.

I have a 107'' pickup chassis that I prepared about 15 years ago, I still have the original leading axle drop box that I fabbed for my original 6x6, the rear leaf springs and central pivots are still there, a couple of Rangey wrecks to donate their axle assy's etc.

What is holding me back is the sense of 'been there, done that', and the knowledge that I wouldn't be happy unless I transferred the running gear from my portall axled vehicle over to the 'new ' 6x6 chassis, and that would involve making another pair of portal boxes.

What has rekindled my interest however, is that when I made a scale drawing of the engine/transmission and driveline layout yesterday,I realised that there was a lot more uptravel available on the U joints of the leading axle propshaft ,but the chassis gets in the way and prevents that, so I had the idea about hinging the chassis just forward of the leading axle bumpstop position, so that it would still be rigid to down forces , but could arch its back like a cat, for when clambering over steep hummocks, big logs etc. When i retrieved the wide angled propshafts from my old 6x6 remains, I remembered how I'd modified the yokes to increase their maximum angularity to 40 degrees.

I'm going to try the principal out in Meccano before I committ, but it looks like it works on paper drawings.A Jeep enthusiast mate of mine has just sold his steel fabrication business, and is moving out to a property not far from me. He has built a huge shed and stocked it with a lathe, milling machine and most of the other good things in life, and he told me yesterday that he is itching to do something unique and interesting. We'll see!

Bill.

Sorry Mods. I didn't intend for all of Fridges photos to be repeated on this thread. I tried deleting them without deleting my post, but they are not co operating. If you can delete them, please do.

[dirtydiesel]

I realise the conversation has moved on a little but here's some pics of the shortened 6x6 Volvo & drivetrain

Have you noticed how they've rearranged the prop shafts an axle directions to shorten the wheelbase down?

Very very clever, is that from offivaruste? Doesn't look soumi-tech enough for the kari's

[bill van snorkle]

Have you noticed how they've rearranged the prop shafts an axle directions to shorten the wheelbase down?

Very very clever, is that from offivaruste? Doesn't look soumi-tech enough for the kari's

Can't really see it all, but does the spur geared PTO on what was originally the leading axle now basically drive both diffs? In the normal configuration is there a dog clutch in the PTO to disconnect the drive to the rearmost axle,or are they permanent tandem drive?

All it needs now is to reorganise the shock absorber location to get some real articulation out of that sucker.

[bill van snorkle]

Webby, it will be grat if you could post some info about everydady driving a 6x6: tyre wear/wind up, braking, turning circle, ubdersteering at high speeds...

You could post it here http://forums.lr4x4.com/index.php?showtopic=81152

Til Webby replies, i'll point out that the standard Sandringham 6 has some type of limited slip differential in the thrudrive to prevent windup, and the wheelbase is significantly longer than what you intend, so turning circle and understeer data wouldn't really apply in your case.

[Troll Hunter]

There was an article in LROI a few years ago that featured a "Defender" 8 x 8, and as far as I can remember it was a series of connections between transfer output shafts and PTO take offs. Unfortunately, I don't have the article still, but I'm sure that a forum "librarian" will have it.

Mike

[Happyoldgit]

Just to let you knw that I have merged the two 6x6 threads as the newer one was heading in a similar direction to the old.

[FridgeFreezer]

Have you noticed how they've rearranged the prop shafts an axle directions to shorten the wheelbase down?

Very very clever, is that from offivaruste? Doesn't look soumi-tech enough for the kari's

Yes, that was one of the Offivaruste crowd - he offered to swap it for the 109, and I did have to pause to think...

Bill - if we had a forum whip-round to fund your data plan, would you be able to post more / upload more pictures of your various creations and modifications? Either that or we'll just post Dan over with a notebook, although I realise Aus customs take issue with importing vegetables.

[bill van snorkle]

Fridge,Dan, I am assuming the shorty Volvo's original leading rear axle assy is now the rearmost axle.The propshaft from the transfercase runs over the leading axle to the rearmost diff, and another propshaft from the PTO on that diff runs forward to the leading diff which has been turne back to front ? So I would assume that the suspension uptravel for the leading diff stops before the axle housing makes contact with the propshaft from the transfercase to the rearmost diff? Probably works ok on that vehicle with the t/case output 36'' off the ground, and what appears to be relatively restricted articulation. Would probably need to lift a Disco chassis up a long way to achieve a similar result I feel.

[bill van snorkle]

Yes, that was one of the Offivaruste crowd - he offered to swap it for the 109, and I did have to pause to think...

Bill - if we had a forum whip-round to fund your data plan, would you be able to post more / upload more pictures of your various creations and modifications? Either that or we'll just post Dan over with a notebook, although I realise Aus customs take issue with importing vegetables.

It is said that once it goes on the internet, it is there forever Fridge. Because I am hopeless at storing Data etc at home, or on my cheaparse computers, I am taking liberties with Teunicos thread here and using it as a data base for my possible future reference.

I really could have used the kind of tech we have discussed on these pages back in the 1970's when I built my 6x6, but there was no internet then, and really no books on how to build the type of vehicle I wanted to create. Some enthusiasts naively believe that if 4 wheel drive is good then 6 or 8 wheel drive just has to be better. Building that 6x6 taught me that is rarely the case, and most conversions end up as a disapointment to their builders, unless a lot of additional engineering and carefull thought and planning goes into the design.The type of 6x6 Teunico is dreaming of and the type I'm interested in is nothing like the LWB expedition camper conversions, Sandringham 6's etc,and the design principals ar quite different too. So if some other nutcase can benefit from the knowledge and experience I have accumulated then they are welcome to it.

Unfortunately, all past records and photos that I had were all destroyed when my cabin went up in smoke in the bushfires we had here in 2009. Whatever data i have posted comes from memory and what I can glean from combing through old bones in my vehicle graveyard.

[Landy-Novice]

maybe its time to create another 6x6 like you old one.

[o_teunico]

I started this tread to see if what I wanted was possible and/or had been ever done. I am taking a lot of ideas and advice on 6x6 building. I hope all the info going here will be extremly usefull in a near future for all the LR4x4 comunity.

Road regulations in Spain can be a limiting factor for me, but would´t affect to people in other places with better regulations.

That Krupp Protze has been a great inspiration. Those belly spare tyres will be easier to build/MoT approve than the tracked arrangement I imagined at first instance. I could even try to get it legalized as "spare wheel carrier".

There will be lots of issues to overcome once a setup has been choosen to build: chassis/axle/propshaft clearence, shock absorber type/location, brake lines limiting articulation, exhaust pipes running where new components should be located...

In my case the most limiting factor is road regulation and intended use of the car. It should have, at least, five comfortable places and be able to be a usefull every day car.

Height could be a problem. Extreme suspension/body lift will solve clearence problems, but with my intended +80mm track I will be allowed by regulations to lift the car a maximum of 150mm. "Calzada da Ponte" is a street I use nearly every day, wich has a height restriction of 2 metre.

If I add that I want some 9.00R16 tyres...you see that I will need a RRC low roof conversion and a suspension/running gear layout that will involve no more than 100mm height gain.

As Bill said "Some enthusiasts naively believe that if 4 wheel drive is good then 6 or 8 wheel drive just has to be better. Building that 6x6 taught me that is rarely the case".

Maybe a 100" bobbed Disco with belly wheel wil do the trick for me. Belly axle beeing driven with a toothed belt from pulley located at t-case brake drum will be easy to do and cheap.

I have three series t-cases at home. Sourcing more will be extremly difficult. Back in 2004/2005 some african buisnessmen saw this area as the perfect source of secondhand parts for african market and took with them all the series stock from local scrapyards.

My soul is worthless and I need all my internal organs, so, an underdrive from Ashcroft will be something unaffordable for me (BTW, they are out of stock). How could I obtain a cheap underdrive? My extra LT230 idea saw clearence problems with chassis, and I will need three gears instead of two. Three gears? Chrysler is the solution! Chrysler A727 auto box used in 80s RRC has a 3rd 1:1, perfect for stock 205R16 road tyres, a 2nd 1.45:1, perfect for 9.00R16 off-road tyres, and a 1st 2.20:1 that will make a good underdrive. And best of all, it is already converted for LT230.

I could source a cheap Getrac 6 speed box from a Ford Transit or ZF from Iveco Daily. After addapting it to Tdi, a short propshaft from 6sp box will drive the A727 (with no torque converter and moddified for no auto-shifting) and it will deliver power trough standard LT230. In this setup engine will certainly need to be moved forward, or alternatively, rear axle flipped and matted to drop-box, as in Bill´s original 6x6, for propper propshaft length.

As consecuence of big-sized tyres in belly axle, door window will have very little down travel. There are situations where you need to take your head off the car to see where are you doing. Solution? Lambo doors! Engineering company said they can be fully legalized if I mount some hinges with "CE" approval.

Lastly, another 8x8 setup, simpler than the one I posted before. Clearence between 3rd axle and 4th axle´s propshaft could be an issue.

Fridge, what are the wheelbases of that superb VOLVO?

I read about a tread called "Bill´s cars" or "Bill´s vehicles" that someone in this forum created to show info on those great machines that Bill made, but have been unable to locate it. Any link?