3 Link ?...or what other options maybe ?

[dirtydiesel]

I see one comment above on the 4-link, and that's it.

Is this possibility under consideration? If not, why not?

Al.

triangulated 4 link works very well as well.

[bill van snorkle]

triangulated 4 link works very well as well.

Is that vehicle finished ? Can see right inside the chassis rail.

I believe Moglite, with a similar system is currently having issues with lateral location . Not enough triangulation as some are fond of saying on Pirate.

Bill.

[Astro_Al]

Moglites issues centre around the fact that some original mounting points on the chassis were used. Resulting in 2 triangulated links per axle and two much straighter links per axle.

There is no intrinsic problem with the four link regarding this, its just in this case.

So I ask again, why not a four link? I'm not trying to sell it, just wonder if it has been considered?

Al.

[GBMUD]

I see that a number of people are concerned about the possible negative impact on on-road handling of a three/four/five link system. What causes this? If the springs are the same as with the original set-up then the handling should be no different - assuming that the three link is corrctly thought out and caster/sideways/fore and aft movement of the axle controlled. Do the original hockeysticks/bushes really offer such a degree of anti-roll?

Our friends across the pond at Chrysler (Jeep) have come up with a solution to the problem of questionable road manners while wishing to improve off-road performance. The detachable anti-roll bar. If your axle is correctly located and the handling is upset by the three link allowing too much roll then fit one - you can even buy most of the bits from Landrover for direct fitment and, if you are planning three link, it is hardly a major undertaking or engineering feat to include an anti-roll bar and a quick-disconnect for it.

Of course, if the problems are not roll associated then I am pi***ng up the wrong tree.

Chris

[MasterSplicer]

Pugwash, Sorry your'e wrong. Perhaps the commercially available 3 link systems are too weak, particularly with portal axles. But as I have built 3 extreme vehicles, 2 with portals, all with upper 3rd links that are used as daily drivers in stop start traffic in addition to offroading in difficult conditions without issues i cannot let your statement go unchallenged.

Master Splicer. The phenomenon you describe when reversing is as expected with a 3 link with lower 3rd. When the Safari Guard unit which had not been fully developed at that time participated in the

'' Defender Twist Off" in the USA some years ago. the system suffered a catastrophic failure during heavy braking . The diff toggled up snapping the propshaft and the truck overturned. Braking whilst travelling forward and reversing imposes the torque reaction forces in the same direction.

If the single 3rd link is placed closer to the axleshaft centreline than the links on each side then it is obviously going to be subject to much more compression and tensile stress. If the single 3rd is placed at double the distance from the axleshaft centreline as the links on each side then the forces on all links should be about equal. It is impractical to do this on a commercial 3 link because that would further compromise the already poor ground clearance these units give. The only way I can see these kits working correctly is if all link end bushings were replaced with non compliant ball joints, but then noise and vibration transmission into the cabin of Defender type Landeys may be annoying.

Bill.

I agree with you Bill al the way but still many people don't realise this at al. When you buy things first time you think it sshould be good and i was one of the very first ones. Til you start to realise these things or even see it your self. And to go and say lets replace al the bushes for rose joints that's something i wouldn't do because then i would take it to another direction. I have tried it and it works makes it lot better and a lot more noise. Advantage is again that you can really hear very clear if everything works in proper order. Vibrations where never any issue really.

[filthy boy]

Moglites issues centre around the fact that some original mounting points on the chassis were used. Resulting in 2 triangulated links per axle and two much straighter links per axle.

There is no intrinsic problem with the four link regarding this, its just in this case.

So I ask again, why not a four link? I'm not trying to sell it, just wonder if it has been considered?

Al.

In those pics above it looks like the upper links are not triangulated. To get sufficient lateral control you need to have sufficient triangulation in both uppers and lowers.

It is worth noting that a double triangulated suspension setup is acceptable under the construction and use regs as providing adequate control. If done properly.

The buggy has 4 link front and rear, both triangulated and we have done loads of modeling so they will hopefully work. But driving it will be the test.

The main problems are packaging the upper links round the engine and having the correct mounting points (position and strength) on the frame.

The bump steer issue is real but can be reduced so it is no worse than on a 2" lifted Defender.

FB

[dirtydiesel]

The pics above were taken part way through the build. That car has been finished for over a year now.

There is absolutely no lateral stability problems.

[MasterSplicer]

So when i am correct then you guys have taken away the panhard rod completly!!?? Must be because that thing is work of the devil.

But the side to side forces are very high so your triangulated arm must be strong as the mountings.

Nice to see people are trying and tackle it the different way,Like it.

You guys had bumpsteer really with this etup?? Little suprised really,would thought it would have bumpsteer in this setup.

Are you also planning front hydr steer as wel??

keep up the good work

[Bush65]

John, in posts on other threads I know you've a few opinions on roll centres, I am definately going the Dobson X-route, and due to packaging of track rod, X-link beam and ram assist all on the front of the axle the panhard rod 'axle mount' is gonna need lifting a little from the standard position. Chassis end will be relocated but stay at the same height, the mount on the axle is gonna need lifting approx 2", Disc will get a 3" lift approx.

As I have to fabricate an A-frame mount for the rear axle, do I raise this mount an equal amount to the front panhard lift to keep the difference in roll centres the same?

Will raising the A-frame axle mount have a positive or negative effect on rear geometry?

Will raising the roll centres have a huge effect on the Disco's handling?

Does any of this make sense?

Opinion invited please.

Andy

Lifting the axle end of the panhard will raise the roll centre a little, which will help in off camber situations. It will also bring the panhard closer to horizontal, which is a good thing.

But, unless you are intending to change the track rod to keep it parallel with the panhard, you will introduce some roll steer.

The A-frame mount on the rear axle determines the height of the roll centre and this will still be higher than your front roll centre.

With lifted suspension, raising the A-frame mount can help suspension travel. I have not heard any adverse comments from others who have done this.

Raising the roll centres by such a small amount should not have much affect on your discos handling.

[Bush65]

...To get sufficient lateral control you need to have sufficient triangulation in both uppers and lowers...

Many other have also assumed this, but it is completely false.

With triagulated upper and lower links, only the links that converge at the axle end (usually the uppers for off road vehicles), provide lateral control.

[bill van snorkle]

In those pics above it looks like the upper links are not triangulated. To get sufficient lateral control you need to have sufficient triangulation in both uppers and lowers.

.

FB

For the purpose of this discussion, take a look at a Defender rear. The ''A'' frame approximates triangulated uppers.The lowers are parallel. Result, almost perfect lateral control.

Bill.

[MogLite]

The problems I was having on my front 4-link appears to be with compression of bushes.

I've now done them up a lot tighter, and the slack does seem to have come out of the system.

Poly-bushes should cure it completely, but I wouldn't expect them to last very long.

Here is my rear suspension using a 4-link, so no reason why you can't have a front 4-link around a sump

Of course its all theory with mine at the moment.

[Guest diesel_jim]

Looks like all the parts have been supplied by $carp-iron.....

/running like hell for the door, sod the hat & coat!/

[dirtydiesel]

In those pics above it looks like the upper links are not triangulated. To get sufficient lateral control you need to have sufficient triangulation in both uppers and lowers.

The main problems are packaging the upper links round the engine and having the correct mounting points (position and strength) on the frame.

The bump steer issue is real but can be reduced so it is no worse than on a 2" lifted Defender.

FB

The upper links are parralel.

The lateral movement on this setup was a little over 4mm measured axle case to chassis, the standard rangy we measured at the same time was moving over 6mm.

What bump steer issue?

We have no disernable bump steer.

So when i am correct then you guys have taken away the panhard rod completly!!?? Must be because that thing is work of the devil.

But the side to side forces are very high so your triangulated arm must be strong as the mountings.

Nice to see people are trying and tackle it the different way,Like it.

You guys had bumpsteer really with this etup?? Little suprised really,would thought it would have bumpsteer in this setup.

Are you also planning front hydr steer as wel??

keep up the good work

There is no panard rod in this setup.

No bumpsteer, just heavy steering

Hydro assist fitted now, you can lock to lock it, with one finger, stood outside the car.

[will_warne]

The problems I was having on my front 4-link appears to be with compression of bushes.

I've now done them up a lot tighter, and the slack does seem to have come out of the system.

Poly-bushes should cure it completely, but I wouldn't expect them to last very long.

Here is my rear suspension using a 4-link, so no reason why you can't have a front 4-link around a sump

Of course its all theory with mine at the moment.

Yeah, I went to see Moglite a week after Andy discovered his problem and as soon as you turned the steering wheel you could see the problem was because the nuts at the end of the central links weren't done up very tight allowing a lot of flex. You could only see it if you got under the vehicle and had someone rock the steering, though. Not very easy if you're working solo

[imspanners]

Forgive my basics, and feel free to rip me to shreds (dons Flak jacket)

I am by no means into the modifications that you guys so ignore me if you wish.

If you had a radius arm that pivoted on 2 axis would that not help the axle droop? or prevent the bushes binding.

For example, using a standard chassis style bush and pin would allow the radius arm to rotate.

Then, immediately after the bush, use a rose joint, allowing the arm to bend.

Obviously a rose-jointed panhard rod would be required.

[dollythelw]

Hydro assist fitted now, you can lock to lock it, with one finger, stood outside the car.

your steering is gay Dan

...........tyre squeelings, waft of burnt rubber through window

[MogLite]

Forgive my basics, and feel free to rip me to shreds (dons Flak jacket)

I am by no means into the modifications that you guys so ignore me if you wish.

If you had a radius arm that pivoted on 2 axis would that not help the axle droop? or prevent the bushes binding.

For example, using a standard chassis style bush and pin would allow the radius arm to rotate.

Then, immediately after the bush, use a rose joint, allowing the arm to bend.

Obviously a rose-jointed panhard rod would be required.

My mate had a set of rear arms done like that. They did work. They did give massive flex. But the 110 handled like a pig when there was some slop in the joints.

In fact the worn out arms are in my garage and have been cannibalised as I was under strict instructions not to use them as they were.

[imspanners]

My mate had a set of rear arms done like that. They did work. They did give massive flex. But the 110 handled like a pig when there was some slop in the joints.

In fact the worn out arms are in my garage and have been cannibalised as I was under strict instructions not to use them as they were.

I seem to remember somebody (on here?) was testing a modified version of a rose-joint, that wasn't as affected by the dirt,. The wear rate was better. Possibly an American import?

[LR90]

I seem to remember somebody (on here?) was testing a modified version of a rose-joint, that wasn't as affected by the dirt,. The wear rate was better. Possibly an American import?

What you're suggesting is good for the back but does't solve the real problem at the front. Here, because each radius arm is attached to the axle by two bushes, when articulating this has the effect of the two radius arms tryig to twist the axle in opposing directions. Imagine as one arm drops and the other is raised.

[bill van snorkle]

The problems I was having on my front 4-link appears to be with compression of bushes.

I've now done them up a lot tighter, and the slack does seem to have come out of the system.

Poly-bushes should cure it completely, but I wouldn't expect them to last very long.

Here is my rear suspension using a 4-link, so no reason why you can't have a front 4-link around a sump

Thanks Danny. I just woke and am still half asleep.

It is difficult for me to tell the relative lengths of the triangulated links when compared to a Defender ''A'' frame by those photos, but it does seem like there is insufficient triangulation to eliminate lateral movement.

Possibly if the links were brought together to a single pivot point at the axle?

Bill.

[dirtydiesel]

Thanks Danny. I just woke and am still half asleep.

It is difficult for me to tell the relative lengths of the triangulated links when compared to a Defender ''A'' frame by those photos, but it does seem like there is insufficient triangulation to eliminate lateral movement.

Possibly if the links were brought together to a single pivot point at the axle?

Bill.

The front links on the buggy i posted up are all around 36" long, with a seperation of about 40" at the axle and about 5" at the chassis.

It has absolutly no problems whatsover with lateral movement.

[bill van snorkle]

The front links on the buggy i posted up are all around 36" long, with a seperation of about 40" at the axle and about 5" at the chassis.

It has absolutly no problems whatsover with lateral movement.

OK thanks, that is another option to add to the file.

I once built a hybrid with 1 upper, 2 lower links and a Watts linkage for lateral control, and bump steer wasnt an issue with that either,as long a I didn't fight the steering wheel. I feel it had something to do with the old Rangey PS box being unpowered for the first 10 degrees or so from centre. If it was powered instantaneously I think it would have bump steered.

Bill.

[MasterSplicer]

What you're suggesting is good for the back but does't solve the real problem at the front. Here, because each radius arm is attached to the axle by two bushes, when articulating this has the effect of the two radius arms tryig to twist the axle in opposing directions. Imagine as one arm drops and the other is raised.

I have used that setup with a rose joint instead of the normal rubbers. Only connected to the axel with one arm on the top.Like the safarigard stetup and that worked very wel.

As a said before i have used the rose joints front and rear and never had any troubles with them. Play on the proper made rose joint takes some time to notice it. I am talking about 50000 km and there are still in use. But i grease them the proper way. And i don't really think that the grease is a lubrication film over the parts but it presses out the dirt and water.

What about the first photo's in this topic did anybody of you has that setup ever seen really. Looks interresting but nobody seems to talk about that setup??

Tried to find some more of it but there isn't really much to find

[bill van snorkle]

I seem to remember somebody (on here?) was testing a modified version of a rose-joint, that wasn't as affected by the dirt,. The wear rate was better. Possibly an American import?

Hmmm. a ball joint that is cheap and has a better wear rate than a Rose/Heim Joint, is protected from dirt/water ingress,can be lubricated without dust mud etc sticking to the lubricant and turning it into grinding paste. I think I will invent something like that. Hang on, it's already been invented, and its called a tie rod end. Not very shiny and blingy. And only attaches in single shear, but if the design is strong enough to cope with the shock loads on steering components of millions of road going and offroad going light,medium and heavy duty cars, trucks and heavy haulers , then surely a link suspension system could be built using them.

Bill.