3 Link front ends

[Warthog]

O.k having just chucked a Gywn Lewis suspension kit under the truck, minus his trailing arms as i have made up my own using Johnny Joints. Now i can see how well the rear can flex and the limitations of the the very strong but flex limiting front end can be.

Looked at the Safari Guard and QT 3 link set-ups and they seem to suit the defenders front end nicely. Without too much modification to other parts on the truck.

But is 3 linking the front end the way to go? I have researched a little and come to the conclusion that the set-up needs to be pretty beefy. As the axle can have the tendancy to toggle under the truck under heavy breaking.

Not looking to produce an RTI Ramp truck just would like to see what i can do to get the best out of the designs available.

Cheers

Mark

[Kev Baldwin]

OK for a weekend plaything but not ideal for a daily driver. Lots of flex at the expense of some driveability. There was an infamous instance of Safari Gard's own truck flipping under an emergency brake test at a suspension shoot out some years ago. The system that failed was alledgedly the prototype 3-link system and was subsequently beefed up.

FWIW Safari Gard is no more so the only off the shelf option these days is the QT system.

Personally I've never seen the point in 3-link for UK style 'muddy' off-roading.

[Hybrid_From_Hell]

I asked this very question a while back when I was thinking of "More" to the front axle articulation.

I didn't (for all sorts of reasons 2 of which was my engine and the soft suspension I have ), but do a adavnced search under my name you'll find quite a big thread :0

Nige

[Warthog]

I asked this very question a while back when I was thinking of "More" to the front axle articulation.

I didn't (for all sorts of reasons 2 of which was my engine and the soft suspension I have ), but do a adavnced search under my name you'll find quite a big thread :0

Nige

Ah Ah.........found it: http://forums.lr4x4.com/index.php?showtopic=7276

3, 4, 5, and X Link..............it never ends

Cheers Nige

I would like to research the X link option............anyone got any fresh links to this design?

[Michele]

I would like to research the X link option............anyone got any fresh links to this design?

Not exactly fresh but when I contacted Dobbins for a Rover X-link they gave it a look and said no way

due to the Panhard mount

Here's the reply:

Looks like the rover XLink is a bit more complex than we first thought.

we were able to study a rover today at great lenghts a few thing we found were that the panard mount is in a bad spot for the Xlink. this can be fixed but we also found that the radious arms are far to close to the diff to offer the correct amount of movment the Xlink needs and also the tie rod sits all to close to the radious arms at the rear of the diff.

having said that at this stage we are not going to manufacture these as a production line product.what we can offer to people is a full custom setup. This will be alot more involved to setup and engineer than what we first anticipated so the build up like this might not be for all.

Though I think someone could fab his own with some axle plastic surgery...maybe...

[nicks90]

[brain splurge mode on]

having alot of these lately

i think i'm right in saying that the reason the front end doesnt flex as well is due to the twisting forces in the double mounting of the radius arms on the axle at each end under flex? The bolt presses against each end of the bush and tries to compress it and then it binds.

Now i know you can overcome this to an extent with drilled/slotted bushes, allowing the bolts going through the bushes to move about/get more compression of the bush and free up some more flex. Not ideal though.

Or you have to do whacky 3 link conversions. Most of these solutions apparently make road handling a bit funny.

So if the problem is just this twisting force against the bushes - why not get rid of the bushes and replace them with johnny joints?

that way there would be no forward/up/down/laterall movement in the joint - probably less movement than a standard bush making the road handling pin sharp - yet it could twist as much as it likes and not limit the flex.

would need new arms making with the joints glued on the end - but i'm sure theres plenty on here who could make a new arm out of 7mm cds with 2 joints on the end in the right places

[brain splurge off]

[Escape]

[brain splurge mode on]

having alot of these lately

i think i'm right in saying that the reason the front end doesnt flex as well is due to the twisting forces in the double mounting of the radius arms on the axle at each end under flex? The bolt presses against each end of the bush and tries to compress it and then it binds.

Now i know you can overcome this to an extent with drilled/slotted bushes, allowing the bolts going through the bushes to move about/get more compression of the bush and free up some more flex. Not ideal though.

Or you have to do whacky 3 link conversions. Most of these solutions apparently make road handling a bit funny.

So if the problem is just this twisting force against the bushes - why not get rid of the bushes and replace them with johnny joints?

that way there would be no forward/up/down/laterall movement in the joint - probably less movement than a standard bush making the road handling pin sharp - yet it could twist as much as it likes and not limit the flex.

would need new arms making with the joints glued on the end - but i'm sure theres plenty on here who could make a new arm out of 7mm cds with 2 joints on the end in the right places

[brain splurge off]

I'm afraid johnny joints wont help much, on the contrary. The problem is not so much the twisting of the bushes, as the radiusarms themselves can twist a fair deal at the chassis end. What happen on articulation is the axle is being twisted between the 2 radius arms. Off course the axle doesn't actually twist, so the bushes need to compensate, with one bolt being pushed up and the other one down on one radius arm and the other way round at the other arm.

It is in fact the same kind of motion (U-shape) as a stabilizer bar, only difference is the stabibar is fixed and its ends are moving instead of fixed radiusarm end and a moving axle.

In the suspension thread HFH started, a twisting axle for Bronco's is also mentioned, which involves a bearing in the axle acasing to allow one end to rotate with respect to the other.

I have recently drilled my front bushes and am very happy with the performance. The car feels a lot more balanced offroading and road handling hasn't suffered much.

I was thinking about a 3/4-link as well, but using an upper third link in the form of an A-frame. Because of the performance of the slotted bushes, this will be put on hold for quite some time.

Greetz,

Filip

[simonr]

Although 3 link works pretty well, most people totally under-estimate the forces on the third link - which is why a lot of them end up crumpling, folding or otherwise breaking. IIRC you get about 15 ton compression/tension - which is way beyond the safe working load of the kind of joints people use. However, if you use a correctly specified joint, it ends up being about the size of a grapefruit!

For my money, drilling the bushes / slotted bushes give a decent improvement in articulation without altering the symetry of the suspension/steering. They still provide a degree of roll resistance - so the vehicle doesn't lean too much on the road - and best of all, it can cost nothing!

There are better solutions than either 3, 4, X link - and I know one or two (three in fact) people using it. I'm sure some enterprising company will come up with something eventually!

Si

[T1G UP]

my new trailers got a 1 link and a panard rod! joints knacked though! plenty flex, couple that with a detachable Anti roll bar and your a way

[GBMUD]

my new trailers got a 1 link and a panard rod!

Trailer?

Or Trialer?

[Mo Murphy]

All I've ever seen people with 3 links do is lie under their Landies (apologies to MOG) trying to repair said 3 link mid-comp ! Says it all for me.

Mo

[SiWhite]

Or Trialer?

He said trailer, not baler

[roguevogue]

All I've ever seen people with 3 links do is lie under their Landies (apologies to MOG) trying to repair said 3 link mid-comp ! Says it all for me.

Mo

I don't recall repairing mine mid comp..........come to think of it I rarely make it to mid comp.

[bill van snorkle]

Go 1 link.It is both the future and the past of offroad suspension design.

bill.

[Mo Murphy]

I don't recall repairing mine mid comp..........come to think of it I rarely make it to mid comp.

[T1G UP]

Trailer?

Or Trialer?

Neither of those!

ones a £19.99 from halfords the other looks like a scrap heap challenge reject. Whats that cage made of.....screwed pipe and fitting?! safe.....? but then again it don't look like it moves much

1 link or cheap and nasty missing link or loads of money 3 link

[bill van snorkle]

Ah Ah.........found it: http://forums.lr4x4.com/index.php?showtopic=7276

3, 4, 5, and X Link..............it never ends

I have just finished re reading all 8 pages of that thread to see if there were any points that hadn't been well covered. It's mostly all there with the possible exception that the advantages or otherwise of One link plus Panhard rod really hasn't been discussed. I stated in one post on that thread that I was perfectly happy with my current 3 link (plus Panhard) set up for its combination of articulation, antidive under brakes, front end squat when climbing etc etc. My opinion still holds true today. However, when I look at the added advantages of sheer simplicity,low maintenance, relative ease of packaging and almost 100% positive torque control that a One link design gives, I am tempted to build one just for the hell of it.

The One link I had on the front of my old 6x6 worked extremely well, but that was such a different creature to any 4x4 that any notions of dynamic behavior don't transfer over too readily to the 4 wheel world.

On the surface of it for front axle application ,I see no disadvantages of a properly designed and constucted one link wishbone and crossmember assembly when compared to the standard radius arm arrangement, re dynamic on/offroad handling, but lots of advantages in mountain goat type crosscountry operation. Anyone have other opinions ?

Bill.

[simonr]

It´s my preferred option too. You have the added advantage of tighter steering lock - as there are no hockey sticks for the tyre to hit - as well.

One link is also, sometimes referred to as ´ínverted A frame´.

Si

[Adrian Turner]

Neither of those!

ones a £19.99 from halfords the other looks like a scrap heap challenge reject. Whats that cage made of.....screwed pipe and fitting?! safe.....? but then again it don't look like it moves much

1 link or cheap and nasty missing link or loads of money 3 link

You liking the 1 link then

[Warthog]

For my money, drilling the bushes / slotted bushes give a decent improvement in articulation without altering the symetry of the suspension/steering. They still provide a degree of roll resistance - so the vehicle doesn't lean too much on the road - and best of all, it can cost nothing!

Si

Well, Drilled (8.5 & 6mm) a fresh set of Metalastik Bushes. Gonna try'em first and see how they go. I do have some Adeprene material (a liitle softer than Poly) Going to make a set and try them too?

Any point in drilling the Chassis end bushes (Polybush) Personally dont see any point, but i may wrong

[Michele]

Errr you should have drilled a couple of holes only

they might last even less so Emmenthal style

[will_warne]

My 2p (for what its worth). I've spent a fair bit of time looking into this and here's my thoughts:

3-link:

Design it and set it up right and you'll have few issues. This is the problem with most setups I've seen as to do it right (upper single link) causes all sorts of packaging headaches. Yes, you'll loose some of the anti roll characteristics which is not desirable on road or at speed.

4-link:

Not ideal for the front end unless doing very major mods as you really want to keep a panhard rod with a Land Rover type steering setup. There are similar packaging issues.

"X-link":

Impossible to make bolt on and there are issues with the panhard rod (however relocating can improve the bump steer situation on a raised vehicle). As Simon said, forces involved are epic meaning HFH type materials are required and serious welding gear needed to stitch it together. However, it does allow you to create a lock out system giving you the best of both worlds. Because of this I will be going down this route.

A-frame/one link:

A nice, simple and elegant solution. More steering lock but can also be a bit of a pain to package. If I was just building a car for low speed work this is what I'd use.

The thing to consider with all these systems is to gain more articulation you need to remove anti roll characteristics. Doing this will be detrimental to the vehicles handling at speed. If this is of any concern then you need some kind of lock out system. One last thing: IMHO balance is more important than outright travel (my old non dislocationg OME setup worked very nicely 90% of the time) and I have seen more than one vehicle with hockey sticks on the back that have performed very impressively.

[dirtydiesel]

I was really impressed with mine at the weekend, 3 link front and rear.

The front is lower and the rear is upper.

The front setup has given a lot lot more grip than i had on hockey sticks, the only problem i've had is that i've made the upper links plug into the std chassis bush (identical to rover setup) and the torque twist hammers the bushes, britpart ones lasted 1 hour, genuine ones still look ok after a day but they allow too much deflection.

[landroversforever]

I understand 3 and 4 link, and i think 1 link, But i cant fathom out how the X link works....can an intelligent person explain it to me please ?

[will_warne]

I understand 3 and 4 link, and i think 1 link, But i cant fathom out how the X link works....can an intelligent person explain it to me please ?

Its far easier to see from a picture/drawing however I'll give explaining it a go. Basically you retain the hockey sticks but only the rear mounts are directly to the axle casing. The front mounts mount to a link that runs along the front (ie perpendicular to the hockey stick) of the axle and pivots at the centre of the axle (ie the mid point between the wheels). This means that anti-dive characteristics are unchanged but much greater articulation is allowed as the bushes in the hockey stick don't bind. Make any sense?