Heavy duty axles to survive hard landings?

[simonr]

I've been given a project at work, to design a vehicle based on one of the big, old American 'muscle car' Pickups, capable of jumping and landing repeatedly, preferably without bending axles or wheels falling off.  The track is likely to be about 70".  I hope to absorb most of the impact energy with the suspension (which will be fairly novel, and use Land Rover parts).

It will be rear wheel drive with beam axles front & rear.

It needs to be based on parts we can get in the UK.  I wondered if any of you had ideas for where to look?

Van & Truck axles seem to be about the right width - but truck axles at least 'feel' too heavy.  It doesn't need a huge diff.

We can of course make the front axle tube easily, if we can find suitable knuckles - but I'd prefer to find an off the shelf rear with a diff.

I wondered about 101 axles - and lengthen them a bit.

I'm afraid I can't give too much away - but you'll understand when the film comes out!  We're going to start prototyping / testing in the next few weeks - mostly on the suspension.

Any ideas?

[Chicken Drumstick]

What sort of weight is the vehicle?

The rock bouncer guys run things like modded Dana 80’s

https://www.wideopendesign.com/off-road/axles-and-components/differential-housing

But suspect difficult to find in the U.K. unless you are prepared to ship. 
 

UK spec lwb JK Wranglers used Dana44’s with lots of upgrades available as something possible to source more locally. 
 

Not sure what a Ford Ranger uses. But the Raptor version is designed to be jumped from the factory. So I’d assume the axle is up to the task. 

[uninformed]

Avoid Salisbury type housings is my opinion.  Over heavy centre section with abrupt change in stiffness at axle tube connection. Yes they can be braced but again overly heavy due to the nature of the housing type. There is a reason no trophy truck, 6100 or top end ultra 4 ever use Salisbury type housings. 

why not full floating y61 axles braced (properly) I also think Mitsubishi shogun rear solid axles fairly stout. 

[simonr]

I'd hope the vehicle coul come in under 1500kg.  It will have a space-frame and an electric drive (Tesla most likely) with a very small (5kWh) battery pack as it doesn't need to travel far, but needs to go fast.

[muddy]

If its a space frame you could have a very tall truss to massively strengthen the case. for the front, the boltable swivels of a landcover would mean you could quickly change an end assembly should the worst happen, What track does two long half shafts give?

 

Failing that twin wheel transits have substantial wheel bearings and I regularly see them running at 6-9 ton gross (even over 10!) so they are obviosly fairly durable, granted the are IFS but could be glued onto a tooob?

 

Will.

[simonr]

I'd forgotten the swivels on a Defender were bolted on - that's one good reason to use them. 

Are any of the big, open steering knuckles used in the US, bolted on?

I reckon, using two long shafts would be about right!  Good idea that man!

Using Land Rover axles on a very American car / film would make me smile on the inside   Particularly if they can be made to survive what's in store for them.

 

[RedLineMike]

2 hours ago, simonr said:

I've been given a project at work, to design a vehicle based on one of the big, old American 'muscle car' Pickups, capable of jumping and landing repeatedly, preferably without bending axles or wheels falling off.  The track is likely to be about 70".  I hope to absorb most of the impact energy with the suspension (which will be fairly novel, and use Land Rover parts).

It will be rear wheel drive with beam axles front & rear.

It needs to be based on parts we can get in the UK.  I wondered if any of you had ideas for where to look?

Van & Truck axles seem to be about the right width - but truck axles at least 'feel' too heavy.  It doesn't need a huge diff.

We can of course make the front axle tube easily, if we can find suitable knuckles - but I'd prefer to find an off the shelf rear with a diff.

I wondered about 101 axles - and lengthen them a bit.

I'm afraid I can't give too much away - but you'll understand when the film comes out!  We're going to start prototyping / testing in the next few weeks - mostly on the suspension.

Any ideas?

spidertrax or evo axles from blackbird @discomikey

 

i wouldnt rush to use landrover axles with bolt on swivels as its pretty easy to eject a complete hub on heavy landings, however the "cheap" opton would be a d2 axle with suitable strengthening & bracing do last a little longer but they do also bend right at the inner knuckle

 

Edited September 19, 2021 by RedLineMike

[simonr]

27 minutes ago, RedLineMike said:

spidertrax or evo axles from blackbird @discomikey

Spidertrax are clearly good but fairly expensive.  I have a slim budget for the prototype - but a decent one for the final build, if it works.  Also hard to get in the UK.  D&G are probably the easiest I guess.  I was holding Spidertrax in reserve for the 'hero' build next year.

Someone else mentioned Evo axles - but there's very little info on line. 

The same someone also mentioned D2 Axles.  It would be easy to chop off the knuckle & glue on a boltable flange.

Whatever we use will get boxed in / reinforced heavily to stop them bending in the middle.  However, the problem is the front axle where there's not much you can do to brace the outer end, from the spring outwards which will be subject to considerable moment forces.

 

[RedLineMike]

27 minutes ago, simonr said:

Spidertrax are clearly good but fairly expensive.  I have a slim budget for the prototype - but a decent one for the final build, if it works.  Also hard to get in the UK.  D&G are probably the easiest I guess.  I was holding Spidertrax in reserve for the 'hero' build next year.

Someone else mentioned Evo axles - but there's very little info on line. 

The same someone also mentioned D2 Axles.  It would be easy to chop off the knuckle & glue on a boltable flange.

Whatever we use will get boxed in / reinforced heavily to stop them bending in the middle.  However, the problem is the front axle where there's not much you can do to brace the outer end, from the spring outwards which will be subject to considerable moment forces.

 

rob at ORA would most likely have stock of spidertrax,

 

 

i definetly wouldnt rush towards a bolt on axle end as from my experience with landrover ones, it causes more problems that it solves, Especially if you are jumping said vehicle

 

are you trying to use conventional springs & shocks or using coilovers / bypass's

 

 

[SteveG]

Have you spoken to Dave at Ashcroft to see what he has on the shelf from his earlier HD axle sales?

[Stellaghost]

Unimog portal axle  406 axles on eBay at the moment at around a grand,that's all I'm saying regards Stephen

Edited September 19, 2021 by Stellaghost

[RedLineMike]

Just now, Stellaghost said:

Unimog portal axle that's all I'm saying regards Stephen

he wants to jump it, not stay on the ground 🤣🤣🤣

[Stellaghost]

Can I have it when your finished with it pleeeeeeeesssssse regards Stephen

[simonr]

23 minutes ago, Stellaghost said:

Unimog portal axle  406 axles on eBay at the moment at around a grand,that's all I'm saying regards Stephen

We have previous for bending them.  The scene in Fast9 where they were driving through a minefield - the armoured car was in fact a mog.
They did survive about a dozen jumps though.

 

44 minutes ago, RedLineMike said:

are you trying to use conventional springs & shocks or using coilovers / bypass's

.Err...no...not even slightly similar.  It's going to use one of my (daft) ideas for suspension.  Simulations in Solidworks Motion look promising.

What is the axle pictured?  The knuckles look the kind of thing I was hoping for.

 

[RedLineMike]

Just now, simonr said:

We have previous for bending them - jumping a Unimog maybe 2m in the air.  If you watch Fast 9, there's a scene driving through a minefield.  The 'Armoured' vehicles were Mogs underneath

 

.Err...no...not even slightly similar.  It's going to use one of my (daft) ideas for suspension.  Simulations in Solidworks Motion look promising.

What is the axle pictured?  The knuckles look the kind of thing I was hoping for.

thats an evo axle from blackbird,
i had tagged you onto there post of FB as its easier than trying to crosspost to here

reason i ask about the suspension is with the d2 axles once you have removed the standard spring platforms, you can truss right to the cast knuckle, much like you can with patrol axles (which are another option as they would be likely strong enough internals wise, once they have been trussed)

 

[simonr]

I'll have a look on FB - I gon't go there much any more, every group seems to turn into a flame-fest for armchair experts.

[simonr]

31 minutes ago, Stellaghost said:

Can I have it when your finished with it pleeeeeeeesssssse regards Stephen

You'd have to join the queue!  Unfortunately, this movie franchise hangs on to everything!

[Stellaghost]

6 minutes ago, simonr said:

You'd have to join the queue!  Unfortunately, this movie franchise hangs on to everything!

Ah well shy bairns get nowt lol regards Stephen

[miketomcat]

Simon have chat with jez before he gave up proto he was talking to I think simca or something like that ( @FridgeFreezer may remember), for axles for the next truck. I know they were commercial digger type affair but jez was not renouned for going slowly or staying on the ground.

Mike

[simonr]

I'd love to chat with Jez again.  I figured he'd moved on from all this & probably wouldn't want to be bothered!

[uninformed]

I’d definitely stay away from LR stuff, especially for the rear. Given its rear wheel drive, the diff /axles will see all the power/torque and even built Rover diffs are marginal 

 

another thing to consider, the stiffer you make the housing the more force the stub axle absorbs (housing will absorb very little) LR stub axles are not great in strength given their size. 

[miketomcat]

1 hour ago, simonr said:

I'd love to chat with Jez again.  I figured he'd moved on from all this & probably wouldn't want to be bothered!

He's on faceache failing that I should have his number somewhere.

Mike

[FridgeFreezer]

Jez is indeed off to greener pastures and other projects, ISTR the diffs/axles he was looking at were something quite heavy designed for the truck / armoured market - but with the prospect of sponsorship the price would've been right even if the weight & package may not have been optimum.

I don't think portals bring anything to this problem though - they tend to be better engineered than regular axles purely because, as TSD put it "when someone's designing a portal axle by definition they're not thinking about cost cutting" but hard landings are not any better for them and you've got more mass than a straight axle of similar strength - plus the leverage putting more stress on everything else.

All I can say based on what I saw & heard from back in the days was that some folks can break anything, and that it's not so much which axle as how you mount it & brace it & design the springs/shocks/bump stops to spread loads / transfer them to the suspension. I've seen folks snap an end off a Volvo or Unimog axle, Jez managed to bend a LR hockey stick fully Z shaped and the axle & mounts were still fine.

I wouldn't even think of 101 axles, they're "only" a Salisbury - they're just a rare and hard to find variant with quite low gearing and welded-on swivels. HCPU's and 130's had a heavier duty Salisbury than 110's but I'd still brace it and probably lower the PSI in the tyres to cushion the blow

TBH for the money I'd look at P38 or D2 axles and just make the design very "quick change" as you can stockpile cheap axles easily - one call to Martin at RR Parts you could probably have him deliver a skip full of working LR axles for very reasonable money - perhaps complete with arms & links to make swaps faster. Stick rally-style quick release fittings on the brake lines and call it good to go, with a motivated team and power tools I'd wager you could swap a bent axle out in less time than it takes to get fresh coffees delivered to set.

If the vehicle is (or can be) significantly lighter than the average P38 or D2 then you're already winning -  but I'm sure you know that and I'm sure your CAD package can tell you a lot more than we can about all the loads etc.

I'd guess that whatever the suspension does, for jumps you want a lot of droop so the load is taken up more gradually (over a longer travel) on landing, and some good hydraulic bump-stops to lessen the blow - I know Jez said they made a hell of a difference on Mouse.

 

Also worth mentioning Nige has (or was developing) ready-made weld-on reinforcement for LR axles so may have bits off-the-shelf that make your life easier;

https://megasquirt-v8.co.uk/diff_offroad.php search "Domex" in the page

[simonr]

 

Thanks John,

A lot of heavy armoured cars are built on F450 or F550 running gear.  This one was built on an F550 chassis, made by Delta in Tbilisi, Georgia.  The axles were massive - but would probably weigh more than the rest of the car.

I think you're right - ill try the initial testing at least with D2 axles (which coincidentally have the same stud pattern as the car it's meant to be!).  As you say, we can swap them out easily - and the crew certainly are motivated!  The Director shouting at you tends to do that!

 

Thanks everyone for your help.  Project starts in ernest today - you've given me a lot of options / fallbacks if something doesn't work!

Si

[Maverik]

Going by how many D2's you see lying around off the road due to chassis rot, There's a good healthy market of axles on ebay for peanuts.

I wouldn't be wanting to put high impact loads through a standard rover ball joint - especially due to the lack of quality balls on the market you dont know what you'll be getting.