Outer Limits 4x4 Board

I just had an idea. I can hear all the gasps now. Has anyone thought of using an independant suspension held in a frame that effectively makes it a live axle? The diff centre and the stubb axles would be held in a single frame that is then mounted on suspension. This would not only lift the diff centre giving you more clearance underneath but would also give you infinite suspension mounting options. You could also adapt steering hubs for the rear and have 4 wheel steer. This would aleviate the need to change anything in the diff to make it turn a different direction to normal cause you could just use the same rear diff with the steering hubs. This may not be totolly suited to heavy vehicles but for lighter buggies etc it should work well. Doing this would also keep you trailing arms up higher away from damage

its a bit late for me to find the thread, but its in the RC section.

you'd have to find a suitable ifs diff, as the CVs would most likely need to be from the front to keep steering. most front ifs diffs are off set to one side, and not centred, but i guess if you're going to all the trouble, then its easy to chop it and centre it, or even build one from scratch.

would be a good idea though, but how would it compare price wise to portals?

edit: i found the thread. check it out.
http://www.outerlimits4x4.com/PHP_Modul ... hp?t=42423
not a real 1:1, but same concept i think

It has already been done plenty of times. Often with hummer axles, to turn an independant axle with portals into a solid axle with portals.
Have a look on pirate and you will find pics.

There was an article on pirate 12 to 18 months ago ago..... saved a few pics.......

toughnut wrote:I just had an idea. I can hear all the gasps now. Has anyone thought of using an independant suspension held in a frame that effectively makes it a live axle? The diff centre and the stubb axles would be held in a single frame that is then mounted on suspension. This would not only lift the diff centre giving you more clearance underneath but would also give you infinite suspension mounting options. You could also adapt steering hubs for the rear and have 4 wheel steer. This would aleviate the need to change anything in the diff to make it turn a different direction to normal cause you could just use the same rear diff with the steering hubs. This may not be totolly suited to heavy vehicles but for lighter buggies etc it should work well. Doing this would also keep you trailing arms up higher away from damage

Toughnut I know exactly what you mean, I figured it out some years back when all the IFS vehicles started showing up. My design would allow the IFS suspension to work as normal on road, then when you go offroad sensors that monitor when you need more wheel travel and useing a hydraulic ram would tilt the frame section same as a solid diff to allow full articulation. The same tilting action could be used on road to tilt vehicle into high speed corners or level vehicle on side slopes.

This would give all the advantages of IFS & solid diffs.

Show me your pics when you finish making one.

Cheers.

haulin or crawlin,

have a look at the red bull rig, it has it done,

i think they copy this idea from buggies

customhilux wrote:haulin or crawlin,

have a look at the red bull rig, it has it done,

i think they copy this idea from buggies

Nah this isn't what I meant. These pics still have independant suspension. The pics above are exactly what I meant. I thought it would have been done before but I can't understand why it isn't done more often. Jag diffs are used all the time in street cars and there are a lot of aftermarket parts for them and some of them run some serious HP. You could put whatever diff centre you like in it and just make axles to suit cause the CV's just sit on the end of the axle. It would cost more to buy and mod a GU diff for example than it would to manufacture a frame to fit a Jag diff centre and put the stubb axles on the ends. I suppose you could even keep the independant suspension as well to get extra travel but it would be heavy and possibly have the 2 different suspensions working against each other over bumps and be very unsteady. Was just thinking out loud. Damb. I haven't even finished my winch truck and I'm itching to try some new ideas on a buggy

the new Discovery does just that, excpet they use airbags to allow the axle to act like a live axle when in low range...
I beleive the new 4wd monthly has a review testing it against all the other big rigs.. i.e. Patrol, Cruiser and it out flexed em all

yeah i was thinking about this a while ago, it's complex and you still have too many cv's to handle the huge forces of big tyres.
here is the thread

http://www.outerlimits4x4.com/PHP_Modul ... highlight=

have a look at the rear of antunacs landcruser that had somthing similar

Matt

If you're not going to have 4ws and with the frame idea then couldn't you use uni joints instead of CV's? Be heaps stronger.

ok, i think i know what you mean. check this out

www.edge.au.com/buggies_sidewinder.htm



i know its not the sort of buggy your talking about, but the rear suspension is what you want i think........in anycase, this is what i wana use on the kart im building, if i can pull my finger out

Cliffy wrote:There was an article on pirate 12 to 18 months ago ago..... saved a few pics......


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This is exactly what I was talking about. I don't see it being a huge deal to fit steering stubb axles to this for 4WS. If your worried about the forces on CV's with big rubber how do you get around that on the front of your vehicle. You could get away without using CV's at all and just use uni joints. Especially on the back where the turning rate is usually much lower than the front.

toughnut wrote: You could get away without using CV's at all and just use uni joints.

Large, good quality unis are expensive, so are custom axles to go with them, and they still include lots more weak links than a solid axle shaft.

Youy could also rotate the diff along its pinion axis and angle one side of the diff directly at one of the hubs, with the other hub running off a dual cardan CV joint. The outers then could be a cardan joint around the size of the outers on a Dana 60, 70 or 80. series.

GaryInOz wrote:Youy could also rotate the diff along its pinion axis and angle one side of the diff directly at one of the hubs, with the other hub running off a dual cardan CV joint. The outers then could be a cardan joint around the size of the outers on a Dana 60, 70 or 80. series.

Interesting idea, but I see 2 problems with this:
(1) it will be hard keeping the diff lubed properly - will need oil seals so the oil stays in the diff.
(2) the wheel will be on an angle (a lot of negative camber) so you will not have a very good contact patch between the tyre and the ground.

ISUZUROVER wrote:

GaryInOz wrote:Youy could also rotate the diff along its pinion axis and angle one side of the diff directly at one of the hubs, with the other hub running off a dual cardan CV joint. The outers then could be a cardan joint around the size of the outers on a Dana 60, 70 or 80. series.

Interesting idea, but I see 2 problems with this:
(1) it will be hard keeping the diff lubed properly - will need oil seals so the oil stays in the diff.
(2) the wheel will be on an angle (a lot of negative camber) so you will not have a very good contact patch between the tyre and the ground.

1. IFS and IRS axles already have oil seals. There is no "grease trap" at the wheel end like there is in beam axles.

2. Not quite what I meant. In the photos from pirate (above) there were two joints at the diff end of the axle and two at the wheel end. My Idea was to rotate the diff so there was a "straight out" to one axle joint (using the normal "longside" of the diff in the case of IFS), and a DC joint (may even be able to get away with a single cardan joint) to the other axle joint from the "shortside". This would allow the diff to be centered if needed, and allow a good supply of oil down the longside of the axle tube. There would be a total of three joints in all, one DC CV joint (diff shortside) and two normal cardan joints (wheel joints).

Pete Antunac's yellow beast used a similar idea. Had cv's (from memory) and the axle tubes angled down to the hubs to get more clearance under the diff pumpkin.

this is the rear of antunac's from werock over the weekend