bespoke portal drop boxes/axles

[carl hurst]

I am thinking about making some new axles for my project,i will be making a pair of new tubes to suite, this is no problem as i have done this type of work before but i have not had many dealings with portal boxes,i have got some designs and good ideas but before i commit to any machining i would like some input from you guys,

[pugwash]

Bill Van Snorkle made his own from scratch. Must be worth talking to him.

[FridgeFreezer]

You could just buy some ends from Portal-Tek, they've done all the hard work for you then. What are your reasons for not using a pre-existing end?

[carl hurst]

You could just buy some ends from Portal-Tek, they've done all the hard work for you then. What are your reasons for not using a pre-existing end?

I cant justify spending all that cash on portal-tek when i am capable of making my own,And it would be nice to make my own as well,

Carl.

[najw]

Given what you and Saley have managed to achieve with the new winch, isn't there the possibility of bolt-on portal boxes for Land Rover axles?

Cost dependent of course, but I am sure there would be a market!

[carl hurst]

Given what you and Saley have managed to achieve with the new winch, isn't there the possibility of bolt-on portal boxes for Land Rover axles?

Cost dependent of course, but I am sure there would be a market!

I looked at this option but it would make the truck wider,maybe to wide so this is my reason for wanting to make my own axle tubes,plus if i run the portal boxes with two gears the wheels will turn the wrong way so to resolve this turn the diff over,I can make new axles quicker than altering old rover tubes,

Carl.

[gsr341]

I looked at this option but it would make the truck wider,maybe to wide so this is my reason for wanting to make my own axle tubes,plus if i run the portal boxes with two gears the wheels will turn the wrong way so to resolve this turn the diff over,I can make new axles quicker than altering old rover tubes,

Carl.

hiya Carl

depending on the ratios you plan on running in the drop box couldnt you put an idler gear in there , wouldnt adjust the ratio just the direction ? cutting the end off a landrover axel and rewelding a new flange on should be straight forward , athough would then require custom half shafts with the short side beeing very short

recon there coulds be a market for a complete kit , could just sell it as an axel swap , of fitted at saley in a few hours

got a fron and rear axel here if you wanted a go , would obvesly need them back once you where done though

[simon red90]

i'd say that there would def be a market for a "so called bolt on" portal package to suit a rover axle. regarding the width issue, i'm going on guess work but volvo and unimog axles are significantly wider than standard rover axles and they have taken off big time. dana 60's are huge in comparrison to a rover axle but in comparrison to other stuff on the market their strength and simplicity is far superior.

take tires as an example. in the last year, challenge truck tire sizes have grown so much, the width aspect will undoubtedly follow, albeit at a slower rate, as some will be prepared to change almost anything to gain the "edge" on other competitors, in this case the extra 4inches beneath the diff is well worth the few inches on each side.

[bathtub]

I am thinking about making some new axles for my project,i will be making a pair of new tubes to suite, this is no problem as i have done this type of work before but i have not had many dealings with portal boxes,i have got some designs and good ideas but before i commit to any machining i would like some input from you guys,

In the Us they just seem to put Hummer drop boxes on any axle & just fit new CPs to fit

[steve_d]

If the extra width was an issue could you not just change the offset of the wheel rims?

Steve

[simonr]

What about using multiplex chain to take the drive between the two shafts?

If you were to hollow out the middle of your drive gear / sprocket, you could wrap it round the end of the axle tube to minimise the additional width.

Another option i've not seen is to use a pinion driving inside an internal ring gear connexted to the wheel. That maximises the contact area between the two - so the gears can be narrower

Si

[carl hurst]

hiya Carl

depending on the ratios you plan on running in the drop box couldnt you put an idler gear in there , wouldnt adjust the ratio just the direction ? cutting the end off a landrover axel and rewelding a new flange on should be straight forward , athough would then require custom half shafts with the short side beeing very short

recon there coulds be a market for a complete kit , could just sell it as an axel swap , of fitted at saley in a few hours

got a fron and rear axel here if you wanted a go , would obvesly need them back once you where done though

Hello,

the idler gear sounds like a plan,then diffs can be left in standard place

What about using multiplex chain to take the drive between the two shafts?

If you were to hollow out the middle of your drive gear / sprocket, you could wrap it round the end of the axle tube to minimise the additional width.

Another option i've not seen is to use a pinion driving inside an internal ring gear connexted to the wheel. That maximises the contact area between the two - so the gears can be narrower

Si

Hello Simon,

I am not a big fan of chain driven stuff,The pinion may be a bit high-tec for what i am trying for but may be worth looking at later,

[Milemarker Type S]

I believe I have said it before... but if you can make a set of portal boxes that simply bolt on the the end of rover axles for sensible money then you will have an awful lot of takers... Yes some people are perfectly capable of welding up portals from other vehicles to fit a different vehicle (I am not definitely not one of those people ) but they are in the huge minority compared to those who just want to be able to bolt stuff on...

As has already been said the use of a idler gear to keep rotation in then same direction is a straight forward option but I do like the the sound of simonr's suggestion- small pinion running inside and internal ring gear...mmm massive reduction ratio... As has also been said the axles would get wider with drop boxes but any portal axle is wider than a rover axle anyway...

Shrek

[carl hurst]

So it seems to be that going from simply making a pair to fit to my own project that the masses may well be interested in 'Bolt on' portal boxes,mmmmmm i will have to come up with something good now,

But still need more ideas,

Carl.

[Milemarker Type S]

So it seems to be that going from simply making a pair to fit to my own project that the masses may well be interested in 'Bolt on' portal boxes,mmmmmm i will have to come up with something good now,

But still need more ideas,

Carl.

Just call the ones for yours a prototype!!

Shrek

[Lewis]

AFAIK Maxi Drive used to manufacture a portal box that bolted onto the end of Rover axles. Perhaps it would be time well spent investigating the success or failure of that product before committing to one of your own

There have been a few threads on this forum where members have expressed opinions as to the suitability or otherwise of the Maxi Drive kit, and/or portal converted rover axles for this application. If I recall correctly the consensus was that they were not suitable

[ThreeSheds]

So we are after:

1) Speed reduction (so that we can fit big/huge tyres and still go slower than std).

2) Improved clearance under the diff.

I did think of 3) Improved clearance under the chassis, but that can be achieved with big tyres...

So I had a thought: How about putting the drop/reduction boxes next to the diff? This would effectively move the tubes down and remove the diff-bulge^* (or move the diff up depending on your viewpoint.

Only problems with this that I see are that you would have to fit seriously uprated half-shafts and CVs, but surely that sort of thing is easier than squeezing in the box outside the chrome balls?

If you then fit longer springs/dampers so as to put the diff input flanges in the original position relative to the transfer box, you have effectively achieved your (my) goals above...

Now whenever I do this sort of thing (have an idea) I think to myself that either somebody has done it already or it's got to be stupid. So.. Although I commend the idea to the Forum, I do it with Teflon hat, coat and running shoes on, and facing the other way...

TwoSheds.

p.s. If by any chance this IS a good idea and somebody makes a fortune from it, the usual fee applies - a free set for me

^*Of course some people might enjoy having a diff-bulge

[Jen]

isn't there the possibility of bolt-on portal boxes for Land Rover axles?

I'm not pretending to be technical in anyway so don't make any technical comments to me, but having visited the Portaltek workshops last october and seen the number of Rover and non-rover axle casings they've been through to find something strong and reliable enough to take portal ends Rob actually ended up manufacturing his own. This was even with the incredible amount of modeling and computer programming to attempt to engineer out the weak points, evenutally the axle casings were just left lined up on the wall and either broken or abandoned.

I think he's still working on the problem but it maybe worth consideration before working on the ends themselves?

[Top90]

The Maxi Drive portal ends were about £9,000 or more for a set of four with all the costs when I asked which put me off the idea.

[Jon White]

Maxi drive used to make one that bolted on to the end of the axle tube.

The problem comes that there is alot of machining to be done, and getting custom made gears produced in relatively small quantities is very expensive.

From what i read the maxi drive solution worked very well, but due to the machingin costs and parts count they were not cheap! Frankly it was cheaper to put C303 axles on.

I think the issue you will find is that you can make something up yourself to fit on your own truck, but producing anything commercially means that the parts become so expensive that very few people will buy them! Can anyone reemeber what the Maxi-drive portal kit cost? I have a figure in my head of around the £2500 mark.

Jon

[Astro_Al]

This thread is getting seriously out of whack. I'm no expert, but I've fiddled with my share of portals & axle ideas, and while I don't see much point to this compared to using something that has already been done, here are some thoughts:

1. Two Sheds - no offence mate, but that is not a good idea. The whole point of portals, apart from torque reduction on the drivetrain, is clearance. All you do by putting the drop boxes at the diff is lose it again, at the expense of a lot of weight. If you don't believe me, draw a piccy on squared paper of 2 undercarriages - both same size tyres, axles, diffs etc, one with dop boxes in the wheels, one with them at the diff. Count the squares under each.

2. Maxidrive boxes were nearer the 10k mark I think, and sold accordingly.

3. If I recall correctly, Maxidrive used a double idler (think of it in a diamond pattern of 4 gears), you could do the same to share the loads between more teeth, allowing, maybe, smaller gears.

4. Simonr - there are portals out there using internal ring gears. Good thinking, but I don't think they generally offer as much drop as a conventional setup. (I think the gearing reduction may tend to be higher too).

5. Gear selection will be critical. For economy, maybe its better to nick gears from something readily available and use those - transfer box / gearbox gears.

Of course this can be done. I'd start by getting hold of 4 or 5 existing portal boxes and making sure I understood what was good / bad about them.

There may be an issue with Land Rover chocolate axle casing strength. One answer would be to offer an exchange service in which you'd add a truss to the top of the housing? Plus possibly a flange / web to support the drop box or steering knuckle. I wouldn't want to rely on regular swivels, but thats me. Re-read what Jen said.

A lot of the issues with existing portals have been done to death - there is a LOT of info out there. The place to start is by reading everything you can find on the net and going from there.

Seems like a lot of effort to keep crappy rover centre sections to me. How about just selling complete axles ready to bolt in instead. You'd have choice of centre too, and people could sell their axles to help finance it.

Hope it helps a bit, good luck. Al.

[Rizla 1]

Just a thought - In Scandinavia they have built huge amounts of rear steer portal trucks using Volvo axles, meaning there are a lot of spare rear axles that can be picked up for 2 or 300 quid each .

Could you not use the drop boxes to make your own axle set up ?

[nicks90]

now i dont know if i'm over simplifying the whole thing, but could it not be done relatively easily using alot of standard parts?

looking at the end of the axle with the stub axle taken off - you have a nice mating surface after the swivel where the stub axle bolted to with a drive shaft sticking through. if that drive shaft was splined all the way along, it could act as a simple input gear into the top cog of the drop box. It would go all the way through and be held in place on the other side by the standard drive flange.

then you have your 3 gears in the drop box as normal and the bottom gear again has a full length splined shaft sticking out and a standard stub axle bolted to the outside of it with your standard disk brake/calliper and drive flange holding it in place.

it would be wider - but only by the length of a standard stub axle.

why would this not work? Most the fabrication would be purely to the box itself to house the gears, but the stud pattern to attach the box to the swivel assembly would be jsut the standard stub axle bolt pattern, same for the other end - and standard drive flange bolt spacing.

excuse my carp picture.

[Guest mortus]

the whole concept is wrong...

to add drop boxes to a land rover axle is ideal, but the people who use them are likely to give them a lot of pain.

the tinfoil land rover axles really are not up to the job of supporting the extra twist on the axle casing. Also it would make the land rover axle +5(?) inches wider at the least, then you add big wheels your vehicular width is gonna be greatly increased.

maybe creating an entire axle would be easier, because its not that much harder, and it gives you all the possible variables.

Chris.

[RPR]

Eaton was the maker of the ENV Land Rover axle and the EV11 portal axles for the Volvo C303. These are roughly equivalent in strength to a Dana 60 and/or Salisbury, so a plenty of axle for 98% of Land Rover applications.

Who is the successor to Eaton?

Would they consider licensing the axle for production? Could the likes of Curry in the US be convinced to undertake such licensed production?

Updated with disc brakes and preferably less expensive CV boots run in Land Rover, Toyota, and Jeep width axles, one suddenly has a commercially viable business, with volume potential to bring the cost down below both Maxi-Drive and Portal-tek prices and no need for extensive R&D.

Just a thought.