Unimog Axles

[FridgeFreezer]

Am I right in saying that's a sort of epicyclic portal or what?

[dollythelw]

yep

[Daan]

I am only guessing here, but I think the UK and Australian for that matter competition scene will evolve and courses will be designed to accomodate proper offroad cross country vehicles. Then the superiority of well designed portal axled competition rigs will become clear. It has been said that no Portal axled truck has ever won the Malaysian Rainforest Challenge. I have prepared 3 pairs of ex Malaysian RFC Volvo axles that were under LandRovers over there, and the dogs breakfast that I had to remove that served as suspension mountings and difflock actuators suggests to me that fabrication and design skills among the portal axled fraternity over there was in short supply, and there is no way those vehicles would be competitive against professional outfits from overseas.

Bill.

With regards to the RFC comment: Yes in the past (and there still are) there were some heaps competing, however, in 2006 there was an interesting duel between two very similar (both Toyota based) vehicles, one fitted with toyotas axles and one fitted with volvos.

The endresult was toyota 1 - volvo 2. The portal showed definate advantages on some stages, but not on every stage, and in the final standings, the toyota axled version was better. This very much depends on the event, the stages and driver skills for sure.

Still, I am sitting on the fence to see what happens, and not making a preference at the moment. Interesting to see 13 pages of bitching about them though...

The UAZ is definately the way to go in my opinion, not to extreme and the best of both worlds; I have looked into them, most people that knew anything about them did not recommend them, as the shafts in them are weaker than the usual land rover carp we know. Maybe jez can tell us a bit more?

Daan

[dollythelw]

I can do some nosing for you Daan, I'll ask a nice man in Russia and see what he says, I know they seem happy with stock UAZ sized tyres (31-33"), the front axle is 170kgs and the rear is 150Kgs. For the price of these axles I'd be surprised if anything more exotic than rolled tinfoil is used for the halfshafts, theres no reason they couldnt be uprated with something funky though - let me see what I can find out

Its merely and observation (and not intended to cause another round of debate) but its interesting to me that the only people that knock portals are those that have never had them.

[RPR]

Its an evolution thing - the Mog 404's are a 1950's axle - Series I timeline. Yet they getting compared to stuff that is made out of unobtanium and then cryogenically treated.

"unobtanium" ..................................... is that definitely better than 1430 ?

[bill van snorkle]

Am I right in saying that's a sort of epicyclic portal or what?

Not quite Epicyclic.

It appears to be a large internally toothed ring gear at the output(wheel) end, driven by a smaller pinion gear at the diff end. similar to some forklift axles I have seen. Should be quite strong due to having several gearteeth in mesh, but to get much drop or lift the hub ratios would have to be very low.

A guy in Aus (Glen Dobbins) built a set for his FJ40. They only had 3'' drop but the ratio was about 3.7:1

Bill.

[RPR]

On the GAZ/UAZ stuff, I spent rather a lot of time in the USSR/FSU in the last Century and despite all the jokes about Soviet design and quality, I came to respect their thinking, especially on the military stuff. The designers knew that they would have quality and availability problems with their raw materials, they knew that their manufacturing techniques were not exactly state of the art, and they knew it would probably be assembled by somebody drunk as a sailor on shore leave, so they built around all that. Everything has triple redundancies and built in safeties.

Take the different approaches to the Main Battle Tank between yon Soviet Bears and the Yankee Eagles.

T82 tank - reactive armour, solid, relatively uncomplex, less power and speed and less accurate than the M1 Abrahms, but a lot less expensive to make and easier to repair than the M1. At least up through the T72, the gearbox cam fitted with a hammer on a chain on the gearbox. The M1 breaks and they need six physicists and a clean room to fix it. The T82 breaks and they expect a drunk squaddy barely litterate to be able to fix it in the field.

People often underestimate Soviet stuff. It may look carp, but it will probably work (albeit often not so well) under the most ridiculous conditions for far longer than anyone would think possible....

[dollythelw]

I can attest to that one

[callum]

if you could still search on pirate you'd find a reasonable thread about uaz protals with some piccies.

if i recall corectly i think there was some sort of flaw or at least not very good part about the design. It could be my hazy memory or it could have been some pirate folks needlessly bleating.

i should expect with a little time and google you could find it, or you could go get a yellow star.

sorry that wasn't much help.

here's some links,

none quite as long as i recall, but nevermind

http://www.pirate4x4.com/forum/showthread....tal+axle+thread general info

http://www.pirate4x4.com/forum/showthread....tal+alternative uaz stuff not very long though.

quick skim read revealed no ne talking about a big flaw, so i must have remembered incorrectly.

[Astro_Al]

Interesting axles! They seem to have the weight penalty of a portal axle but only a minor lift / gain in clearance. Which may or may not suit the application, but for me the deal breaker is the lack of a locker.

There appear to be discs available, perhaps you could rig up a kind of wheel-spin-related differential braking system to 'lock' a spinning wheel and send some torque the other way.

Sound kind of lightweight too - might work great in a lightweight nimble single seater, but we don't really have those in the UK...?

Still, interesting.

Al.

P.S. just seen the clearance gain is 3 inches, so not too bad.

[reads90]

I have not been reading the last few pages just scaned them.

Ali what are you up to you, Your sounding like Mark with his Yank 440 V8 with blower and nos 125 kit. I still think even the yank axles he is useing will struggle to hold all that power in and its only on 12,50's.

I recon the tyres will melt with his driving on tarmac..

mmm jules the YELLOW one on the vid, saw it the other day in a garage mmmm not a landy but nice, and nice sound

[Astro_Al]

mmm jules the YELLOW one on the vid, saw it the other day in a garage mmmm not a landy but nice, and nice sound

...anyway... portals.

So I thought I'd throw in the hummer suggestion.

Anyone got any thoughts? Personally I don't think they're a bad option. The rumours of 100 USD per box never seem to lead anywhere real, but they can still be bought and are build for some pretty heavy trucks, and I think would survive pretty well under a Uk sized vehicle - especially with UK power levels too. I see them somewhere between a Volvo and a Mog box.

The main issue, of course, is the fact that they need to be grafted onto an axle...

Still it's not rocket science.

Al.

[bill van snorkle]

...anyway... portals.

So I thought I'd throw in the hummer suggestion.

Anyone got any thoughts? Personally I don't think they're a bad option. The rumours of 100 USD per box never seem to lead anywhere real, but they can still be bought and are build for some pretty heavy trucks, and I think would survive pretty well under a Uk sized vehicle - especially with UK power levels too. I see them somewhere between a Volvo and a Mog box.

The main issue, of course, is the fact that they need to be grafted onto an axle...

Still it's not rocket science.

Al.

Humvees have independant suspension and inboard brakes which means the portal boxes do not have flanges to adapt to beam axles, or brake caliper mounting points, so it makes them difficult to fit the closed swivel housings as on LandRovers etc. The gears, shafts, bearings etc look good , the drop is 3 3/4'' compared to around 4 1/2'' for Volvo's and Mogs, but if they were available cheaply enough, for anyone with fab and machining abilities it's not to difficult to make some steel boxes to suit. I wish I had a load of Hummer gears and shafts when I was making my own portals. Apperently there are lots of them at the US military garbage dump in Bagdad. Anyone care to go there for a scrounge?

Bill.

[dollythelw]

Apperently there are lots of them at the US military garbage dump in Bagdad. Anyone care to go there for a scrounge?

Bill.

Having bounced in Brixton and Slough amongst other centres of culture I'd take that as a bit of a holiday

why not an indy buggy with hummer portals?

[Hybrid_From_Hell]

RIGHT !

I have the answer - its so simple its amazing we haven't thought of it before.

We need to Get Simon R involved,

With some clever pics, balsa wood, sticky tape glue and bits we get him to 'fabricate up' (with some clever photoshopping done on it all) he then "Launches" the 'New and exciting' :

X-Portal Kit

404 axles, with disc conversion, prop conversion flanges,complete with a full nuts and bolts and brackets fitting kit, all fully refurbished too - launch price say £500 complete................

Within a month or 2 Scrapiron' will copy the idea, ......and launch their own "Unique"

SIR Portal Kit

404 axles, with disc conversion, prop conversion flanges complete with a full nuts and bolts and brackets fitting kit, finished in Puke orange, all fully refurbished too -but only £499 complete

Orange - well, we can't have it all

Nige

[Astro_Al]

why not an indy buggy with hummer portals?

Man I'd love to build a lightweight single seater. Real small and light. That'd be an interesting setup for sure. I'd never considered keeping the inboard brakes and I.S., but...

Of course with indy susp you get moer clearance in the centre anyway - so are the portals necessary...? Discuss...

It's more a question of shoehorning in the driveline - I've never been a fan of the idea of having the gearbox/propshafts between my legs though. I guess it's irrational.

Anyone know why we don't see this kind of truck in the UK (yet...?)?

Nige - sounds like a plan! Maybe we could 'buy' enough to put them out of business.

Al.

[Mark90]

You mean something very like the 'Rock Rod' that Neil Whitford built for modified trials? That's where you see the single seat stuff in the UK.

[Astro_Al]

Kind of...

Got the specs on it?

Al.

[dirtydiesel]

I now belonds to rog (898kor).

It has 2.7 bmw engine, 4sp auto, thwaits tfer case, bmw diffs (rear now lsd) and it has 14" under its diffs

[bill van snorkle]

You mean something very like the 'Rock Rod' that Neil Whitford built for modified trials? That's where you see the single seat stuff in the UK.

Too many bits below axle centreline. Take a look at a Jaguar rear end. The upper lateral control arm is the universally jointed halfshaft. The bottom control arm is a tubular link rod. Now redesign it for offroad use by making the halfshaft the lower link and placing the former lower link above. Articulation will still be not as good as beam axles though.

Bill.

[jules]

I have always thought these look so much fun..

One of the racing boys I don't know who had a gear box blow up and take a big lump out of his co-drivers leg

so I with you in that with the box between your legs..

[Mark90]

Prop speeds much slower in trials/challenge than speed events so less likely to punch through if yo have some decent plating in the floor/tunnel. 10mm or 1/2" plate Nige?

[dollythelw]

ahhh but is ultimate articulation the end game? an indy with portals would in theory give advantages in terms of ground clearance over a beamer with no portals and still be able to hold higher speeds as the unsprung would be much lower.......

what d'ya reckon? can you tell I've been scribbling on the whiteboard recently

[Daan]

I believe the way forward is a de dion axle; both wheels in line, but the diff fitted solid to the frame. The swiss army vehicle called duro has got this and it combines the advantages of both systems.

[bill van snorkle]

ahhh but is ultimate articulation the end game? an indy with portals would in theory give advantages in terms of ground clearance over a beamer with no portals and still be able to hold higher speeds as the unsprung would be much lower.......

what d'ya reckon? can you tell I've been scribbling on the whiteboard recently

I think it really depends on the conditions you want to compete in. I am still not convinced about stability of independant suspension in relatively low speed severe axle articulating stuff. The Hummer on the ramp episode and watching Haflingers and Pinzgauers getting all tippy in places where a beam axled 4x4 just walks through is what sticks in my mind when independant suspensions are mentioned.

Bill.