Portal Axled Trucks

[Corrode Finger]

Jez

Thanks for the replies, at the moment it is exploratory. Its got to be cheaper to explore a concept on here with 2000 plus members brains to pick than go out, buy it, and bin it cos its too hard.

I would like to do 'a something else', having completed a simple build(in your terms) i feel i have the comfort to explore ideas, and create and erase 'vapour trucks'( to quote fridge in his favourite line).

If i dont ask, i will never know. I am sure i will be back with some other crazy idea for a thread.

Its good to be able to use the forum, for exactley that, a place to explore and pontificate!!

It would be nice if anyone else has questions on this to carry on asking, as a new brain may actually spark something else off.

[sheeppimp]

ok, not quite along the same lines but related and one of those i wonder thoughts:

rather than a standard portal axle i.e. straight with drop boxes has anyone ever created a beam axle where the tubes are angled down in an inverted V. I would think the diff would need to be central. From my limited knowledge this would seem to be an obvious way of increasing ground clearance and keeping the diff well up while still keeping a simple construction. It would still perform as a 'normal' beam axle

I appreciate this is probably not a home build project what with the casting of the axle so am really thinking has a manufacturer done it? or am i missing something obvious?

[Ex Member]

You would then have CV or U joints at the diff and at the hubs (4 per axle). Plus the diff clearance to the vehicle would be hard to maintain.

[Astro_Al]

Yup, thought about it quite a bit.

Basically a 'fixed geometry' independent suspension style axle (for example with upper and lower A-arms / wishbones, but all welded instead of able to pivot). You just spring the whole shooting match as one unit like a beam axle.

Easy to do with a centre section and some hubs. Shafts between them just have joints to cope with the cycling angle each revolution. Exactly as an indy setup.

Probably a pretty easy axle to build as any crapness of angle is gonna be soaked up by the UJs.

I even went as far as posting the idea up on Pirate, needless to say it was shot down in flames. Then someone (Rusty, I think) went ahead and built one and it works great apparently...

Of course, nearer the wheel hubs you lose clearance, unlike a portal axle. Also the more joints and UJs etc you have, the more there is to fail / maintain.

No need to keep the diff central, the limiting factor will be the operating angle of the UJs - as long as the short side angle doesn't exceed this, I see no reason to keep the lengths the same.

It could be done at home - there is no casting. All you need is a frame that holds the hubs and diff in a fixed relationship. It could be open or closed, sheetmetal, tubework, plastic bags and zip-ties, whatever!

Cheers, Al.

[Corrode Finger]

sheeppimp and astro al.

being slightly dumb, i have tried with basic pics to visualise what you are saying.

Is it something like this very basic sketch(bunch of blocks)?

[Astro_Al]

Yup, thats exactly it!

Al.

[Bush65]

Jez,

Here is a pic of the Marks portal nissan axle.

And some more info from their web page where that pic came from.

Regarding the inverted V axle, Pete Antunac did that many years ago on his FJ40 toyota in Aus. There was a recent thread here with a video clip of his FJ40. From memory you could see the V axle in the video, but most people probably concentrated on the suspension.

There were some pics on pirate of a rear V axle that was used a truss made from tube (and hummer parts from memory).

Back on topic!

IMHO people putting volvo portals under rovers have taken the more appropriate route. Less work than another body and engine on a forward control C303.

The downside of the C303 portals, is getting spares - is that situation going to be better if you use even more C303 stuff

BTW, I have 6:1 volvo portals (not for sale, so don't ask). Will have to chase up portaltek again and hope to get better responses than before.

[bill van snorkle]

sheeppimp and astro al.

being slightly dumb, i have tried with basic pics to visualise what you are saying.

Is it something like this very basic sketch(bunch of blocks)?

This has been done before on a few occasions. Peter Antanuc,a bloke over here who wins Tuff Truck alot had got a setup like that on the back only ? with rear steer, and it worked quite well for the limited mileage that these type of vehicles actually do. It may work well on high mileage vehicles too but the mob over on Pirate, reckon it's a carp idea citing U Joint failure as their reason. I don't necessarily agree that UJ's or Birfields permanently operating through a relatively mild angle of 15 degrees (depending on axle width)or so would be problematical, but this arrangement more or less dictates that the differentials be centre mounted, which for a front axle may create engine clearance difficulties. Also steering joints are copping full torque rather than being protected by the gear reduction as in conventional portal axles.

If I seem over enthusiastic to respond to questions on this thread it,s because there are very few portalled vehicles, either standard or conversions here in OZ, and the subject still fascinates me.

Bill.

Sorry John. We must have been typing our responses simultaneously. You beat me to it.

The information on their website is a little misleading in thatthey say the track width is increased by 100 mm per side, then goes on to state that correct steering geometry is restored by altering the wheel offset. I think it should read that the drop boxes are 100mm thick, which would upset steering geometry, but this has been corrected by providing wheel rims with greater negative offset.

[Corrode Finger]

Bill,

As i have said elsewhere in this thread, i know only the minimum about portals, hence why i asked the initial question, it was a case of approaching a 'common'(relative in portal terms) installation from a different angle.

I had not been aware of anyone here asking the questions and thought that, if nothing else, it would be interesting and informative.

I like the idea of 'challenging' the accepted ideas, even if they are the best. At the end if the day if someone else besides me gets an idea, or inspired it must be good.

Please post other things related to this topic, as i have said, it possibly needs some new brains to ask questions, that i have not thought of or considered.

As has been said earlier, you are probably the person with the most experiance in this area because of what you have done.

At the end of the day, i am exploring lots of ideas in many ways, for future projects, and am happy to ask questions that some people may find simple, so that i can learn.

[Bush65]

Here is another pic of the Marks portal box

From this web page that has more pics/details of the internals etc. during the development project.

[bill van snorkle]

Bill,

As has been said earlier, you are probably the person with the most experiance in this area because of what you have done.

I honestly believe that quite a few members of this forum have as much if not more hands on general knowledge and experience on this subject as myself. Jez, John Aka Bush65, Dan Aka Dirty Deisel,etc etc all have enormous experience and street cred when it comes to building vehicles to do what their original makers never even dreamed was possible.

I feel a little uncomfortable wearing the Oracle tag among such illustrious company.

Bill.

[RPR]

I feel a little uncomfortable wearing the Oracle tag among such illustrious company.

Bill.

Bill,

Entirely unintended I know, but that is exactly the sort of statement that demonstrates expertise over yatta, yatta. Your candour is appreciated almost as much as your knowledge and expertise. Plain spoken Oz home truths: priceless.

[dollythelw]

"Bent beams" - already available - Overkill Engineerings "Atomic Axle" (have a peek HERE) looks groovey but (isnt there always a but ) the servicing looks like its gonna be fun if/when you do pop a UJ, the ground clearance looks cool though..

Thanks for posting those pics and links John - looks like a neat bit of work.

The spares availability for Volvos is in some ways getting better and others getting worse. Genuine track rod ends are gone AFAIK so we've machined up heim conversions and sorting out an adaptor to take you back into the stock tie rod, kingpin push conversion kits, STEFA seal conversion housings etc, all the seals/bearings/CVs/Shafts etc are easy to source, Ive been tied up with Portal Tek for a couple of years cooking up wierd stuff so the CTIS kit is inbound as are monster shaft upgrades, the new generation disc conversion is FINALLY shipping out

keep me out of the annointed list Bill - one day maybe, but Ive got a long way to go yet

[Bush65]

...The spares availability for Volvos is in some ways getting better and others getting worse. Genuine track rod ends are gone AFAIK so we've machined up heim conversions and sorting out an adaptor to take you back into the stock tie rod, kingpin push conversion kits, STEFA seal conversion housings etc, all the seals/bearings/CVs/Shafts etc are easy to source, Ive been tied up with Portal Tek for a couple of years cooking up wierd stuff so the CTIS kit is inbound as are monster shaft upgrades, the new generation disc conversion is FINALLY shipping out...

Yes for axle parts, enthusiasts like youself have helped with some aftermarket stuff.

But you can't compare availability of rover parts for the suspension, transmission, steering, brakes etc with a C303, which was not in wide use and is how old now (30 years ??).

[CosZuki]

If nothing else this thread has become a mine of information Re portals. i cant wait to actually see touch smell my own! ho hum soon enough they will be in my own hands. Just for point of note my main reason for heading this route is after seeing vehicles fitted with these in action and talking to people from these parts.

My tuppence is that using th eequation Jez posted, the 303 axles offer best results for money, are off best weight and reliabilty, yes some parts are a little scarce but can be found and getting easier from what i can gather as market demands go that way. its the wonderful supply and demand thing. people are demanding and supply is lacking so profit can be made and people are strting to try and make some profit.

Jez you may recall having a not too different conversation with The Muse onboard as he was intrigued to try and come up with a new method of drivetrain, i am emailing him this thread as i think its just what he was after! for the record Muse had never driven offroad before and never worked on a 4x4 but was on same track as corrode finger wnated to know more and try to make something different.

I'm afraid i only got as different as portals on a LWB SJ pick up as i thought it was a good compromise on weight, size with Jez we started looking at power plants alas my preferred choice of HOnda V6 has been ruled out so hence Cosworth came into the fray, small light(ish) and has some poke. ideally i would say a small light diesel but these are not quite so available, and as always cost was a key factor!

Sorry i thinki gone off topic and rambled here. cant even blame beer yet

James "you can carry on now" Robertson

[Corrode Finger]

Thanks Coszuki, i never imagined that this thread would evolve in such a way, i probably never really knew what reaction people would have to such a obtuse approach to a recognised solution.

I never knew that hummvees were a source of portal components, never knew alot of things before starting this. I honestly thought that portals only consisted of Unimogs, Volvo's and Maxidrive.

I geuss the next question, possibly too 'sensitive', is what ways can protals be improved. If you guys are working on stuff that is 'top secret' and dont want to say, i understand.

Is there an evolution to portals, by gaining more clearance/ better characteristics, something else?

[bill van snorkle]

I geuss the next question, possibly too 'sensitive', is what ways can protals be improved. If you guys are working on stuff that is 'top secret' and dont want to say, i understand.

Is there an evolution to portals, by gaining more clearance/ better characteristics, something else?

I think the 4 shaft portals as produced by Maxidrive and now Marks 4wd is the latest improvement in portal design in that the 2 idler gears effectively doubles gear tooth contact for increased strength. That's about it apart from the possible use of lighter materials to reduce overall unsprung weight.

Bill.

[dirtydiesel]

I geuss the next question, possibly too 'sensitive', is what ways can protals be improved. If you guys are working on stuff that is 'top secret' and dont want to say, i understand.

Is there an evolution to portals, by gaining more clearance/ better characteristics, something else?

The only avenues i feel i have got to play with are either mog60's or mog9's mainly to reduce the weight a bit and to improve the strength of the r&p wilst gaining a better choice of ratio's and a shorter diff nose would help with packaging.

The "other" little thing i'm looking at at the moment is to abandon portals alltogether, and go for a straight axle that uses epicyclic hub reduction for its strength and gear reduction.

I have my eyes on a set that'll spin 50's easy (not without a significant weight penalty like, but i've learned to live with the lard this long )

[CosZuki]

Dan? shed weight?

woo hoo nice post number

[bill van snorkle]

The "other" little thing i'm looking at at the moment is to abandon portals alltogether, and go for a straight axle that uses epicyclic hub reduction for its strength and gear reduction.

I have my eyes on a set that'll spin 50's easy (not without a significant weight penalty like, but i've learned to live with the lard this long )

Dan, silly question, Have you seen a Roadless Traction 109 Landy, sometimes referred to as a Forest Rover? Epicyclic (planetary reduction hubs) 11x00 x28'' (50'') or 13.50 x28''(55''?) optional tyres etc etc.

BTW, where would you use such a vehicle ?

Bill.

[Corrode Finger]

IIRC they were built in the 50's / 60's for forestry work.

Now very rare, like rocking horse droppings!!