3 Link Q

[sierrajim]

I'm in the process of redoing the 3 link in the front of my car that was done by the previous owner.

Car is Suzuki Sierra, Coilovers and pneumatic bumps being fitted as part of this.

Currently it has lower links 1130 long and the upper at 540 long, obviously LOTS of caster change as the suspension cycles resulting in an "interesting" drive.

I've got two options:

1. Run the 3rd link (upper) from diff to chassis, i can get up to 700-800mm, however it is VERY tight with exhaust, transfer case and gearbox cross members.

2. Run the 3rd link (upper) back to the lower link which will allow for better clearance. This seems to be quite common in the US on Suzuki and Hilux conversions, presumably due to space constraints.

Has anyone had much to do with option 2? I believe some Jeep Wrangler kits adopt a simplar system, would it be strong enough to have the upper on one side only or would it be best to run on both. It should limit caster change as its almost a raduis arm setup.

[Guy]

I'm in the process of redoing the 3 link in the front of my car that was done by the previous owner.

Car is Suzuki Sierra, Coilovers and pneumatic bumps being fitted as part of this.

Currently it has lower links 1130 long and the upper at 540 long, obviously LOTS of caster change as the suspension cycles resulting in an "interesting" drive.

I've got two options:

1. Run the 3rd link (upper) from diff to chassis, i can get up to 700-800mm, however it is VERY tight with exhaust, transfer case and gearbox cross members.

2. Run the 3rd link (upper) back to the lower link which will allow for better clearance. This seems to be quite common in the US on Suzuki and Hilux conversions, presumably due to space constraints.

Has anyone had much to do with option 2? I believe some Jeep Wrangler kits adopt a simplar system, would it be strong enough to have the upper on one side only or would it be best to run on both. It should limit caster change as its almost a raduis arm setup.

Is it on a suzuki diff housing ..
If so I would question the durability of the hosing to taking the torsional load.

[sierrajim]

I'm in the process of redoing the 3 link in the front of my car that was done by the previous owner.

Car is Suzuki Sierra, Coilovers and pneumatic bumps being fitted as part of this.

Currently it has lower links 1130 long and the upper at 540 long, obviously LOTS of caster change as the suspension cycles resulting in an "interesting" drive.

I've got two options:

1. Run the 3rd link (upper) from diff to chassis, i can get up to 700-800mm, however it is VERY tight with exhaust, transfer case and gearbox cross members.

2. Run the 3rd link (upper) back to the lower link which will allow for better clearance. This seems to be quite common in the US on Suzuki and Hilux conversions, presumably due to space constraints.

Has anyone had much to do with option 2? I believe some Jeep Wrangler kits adopt a simplar system, would it be strong enough to have the upper on one side only or would it be best to run on both. It should limit caster change as its almost a raduis arm setup.

Is it on a suzuki diff housing ..
If so I would question the durability of the hosing to taking the torsional load.

Sorry, 60 series Cruiser housing.

[Guy]

I'm in the process of redoing the 3 link in the front of my car that was done by the previous owner.

Car is Suzuki Sierra, Coilovers and pneumatic bumps being fitted as part of this.

Currently it has lower links 1130 long and the upper at 540 long, obviously LOTS of caster change as the suspension cycles resulting in an "interesting" drive.

I've got two options:

1. Run the 3rd link (upper) from diff to chassis, i can get up to 700-800mm, however it is VERY tight with exhaust, transfer case and gearbox cross members.

2. Run the 3rd link (upper) back to the lower link which will allow for better clearance. This seems to be quite common in the US on Suzuki and Hilux conversions, presumably due to space constraints.

Has anyone had much to do with option 2? I believe some Jeep Wrangler kits adopt a simplar system, would it be strong enough to have the upper on one side only or would it be best to run on both. It should limit caster change as its almost a raduis arm setup.

Is it on a suzuki diff housing ..
If so I would question the durability of the hosing to taking the torsional load.

Sorry, 60 series Cruiser housing.

Cant seen an issue with that housing

[Evil 73]

Put bundera radius arms in it (flipped) with johnny joints at the chassi end and it should still flex pretty good unlike rubber bushes. I'll give you a set of radius arms to try for length and fitment.

Ben

[sierrajim]

I'm in the process of redoing the 3 link in the front of my car that was done by the previous owner.

Car is Suzuki Sierra, Coilovers and pneumatic bumps being fitted as part of this.

Currently it has lower links 1130 long and the upper at 540 long, obviously LOTS of caster change as the suspension cycles resulting in an "interesting" drive.

I've got two options:

1. Run the 3rd link (upper) from diff to chassis, i can get up to 700-800mm, however it is VERY tight with exhaust, transfer case and gearbox cross members.

2. Run the 3rd link (upper) back to the lower link which will allow for better clearance. This seems to be quite common in the US on Suzuki and Hilux conversions, presumably due to space constraints.

Has anyone had much to do with option 2? I believe some Jeep Wrangler kits adopt a simplar system, would it be strong enough to have the upper on one side only or would it be best to run on both. It should limit caster change as its almost a raduis arm setup.

Is it on a suzuki diff housing ..
If so I would question the durability of the hosing to taking the torsional load.

Sorry, 60 series Cruiser housing.

Cant seen an issue with that housing

Sorry, should have been a little more clear, not so much the strength of the housig but the load applied to the links and chassis.

On a conventional 3 link there are 3 chassis mounts, on this setup there is only two.

Yes a Patrol/Cruiser has the same set up, they were however designed for coils to start with.

[chunderlicious]

personally id go to the chassis, i know the link design your talking about but you would prolly have to change the lowers aswell. zook60 may have used something huge but might not have. think of the load on the link.

go the tight space as much as possible and converge the top and bottom a little more. the exhaust can be made however it needs to be done to clear the links. the transfer will be the limit.

i know from experience how much bad castor can fark up a cars ride. i did it with flynns hilux before changing it to be a bit longer and unfortunately converged them a little more because opf space at the time. it brakes a bit weird now (just doesnt feel right) but drives at speed heaps better all through the flex range.

then again the jeeps do seem to work well. but check the material strength first on the lowers, the diff rotates quite a bit on the front under acceleration, no matter how much seperation. just a thought

[sierrajim]

I have a set of Hexbar links here that i can use for some added strength, perhaps i might use them afterall.

[Guy]

The area you go back to will not be as much of an issue as the links ability to resist bending at the point where the forked/3rd arm attatch's to it.

You can easily make the chassis strong enough in that area

[sierrajim]

The area you go back to will not be as much of an issue as the links ability to resist bending at the point where the forked/3rd arm attatch's to it.

You can easily make the chassis strong enough in that area

It's my understanding that the links are 12mm wall, waiting on confirmation of that ATM.

New links were on the plans in the coming months anyway, might just give it a go and if it sucks monkey butt i can change it again.

[ZOOK60]

The area you go back to will not be as much of an issue as the links ability to resist bending at the point where the forked/3rd arm attatch's to it.

You can easily make the chassis strong enough in that area

It's my understanding that the links are 12mm wall, waiting on confirmation of that ATM.

New links were on the plans in the coming months anyway, might just give it a go and if it sucks monkey butt i can change it again.

Yep they are 12mm hollow bar

[sierrajim]

The area you go back to will not be as much of an issue as the links ability to resist bending at the point where the forked/3rd arm attatch's to it.

You can easily make the chassis strong enough in that area

It's my understanding that the links are 12mm wall, waiting on confirmation of that ATM.

New links were on the plans in the coming months anyway, might just give it a go and if it sucks monkey butt i can change it again.

Yep they are 12mm hollow bar

Cheers mate.

[MART]

I run a single centre link back to the gearbox mount , it seems to work allright , it has noalathane bushes out of a patrol . It cops a hiding not only when 4wdriving but on road when breaking this is where the biggest load wil occur , do you think a link on one side would collapse under the pressure , also the top and bottom links are the same length to avoid the diff rolling to much under articulation , Cheers Paul.

[mud4b]

i dont like the number 2 option as it tends to bind heaps quicker than setup number 1.

if you go the longer 3rd link run it right back to the tcase mount, but on the mount for the diff you can lean it forward to give you the length. you will find that having such long links the caster does not change that much even if there is 200 to 350mm difference between lower and upper.. but when it is enough to notice you will be going slow more than likely anyway...

cheers mark

[KiwiBacon]

I run a single centre link back to the gearbox mount , it seems to work allright , it has noalathane bushes out of a patrol . It cops a hiding not only when 4wdriving but on road when breaking this is where the biggest load wil occur , do you think a link on one side would collapse under the pressure , also the top and bottom links are the same length to avoid the diff rolling to much under articulation , Cheers Paul.

A link on one side only will jack that side under braking.
Interesting to say the best, scary and dangerous to say the best.

The system needs to be as close to balanced as possible. There are production systems that work being assymetrical (torque bar on the diff on leaf sprung hilux/surf etc) but it's best avoided.

[mud4b]

I run a single centre link back to the gearbox mount , it seems to work allright , it has noalathane bushes out of a patrol . It cops a hiding not only when 4wdriving but on road when breaking this is where the biggest load wil occur , do you think a link on one side would collapse under the pressure , also the top and bottom links are the same length to avoid the diff rolling to much under articulation , Cheers Paul.

A link on one side only will jack that side under braking.
Interesting to say the best, scary and dangerous to say the best.

only on paper or unless you run stupidly soft suspension and no swaybars, in actual setup and set up properly it works really well without jacking under braking...

not saying your wrong bud or trying to cause a stir.
cheers mark

[KiwiBacon]

only on paper or unless you run stupidly soft suspension and no swaybars,

Well that does describe most 4wd's.

[killalux]

i say don't go with option 2, i had it on a hilux (i had one going back on left and right side instead of just left) originally i had 8mm wall lower arms, they bent badly first time offroad.
it also drove shifull on road, bad death wobbles over about 40km/h.

i did flex well though

[sierrajim]

OK so i've worked out most of it, made the diff end bracket and sorted out my clearances. This now means that i'll have to install the turbo to move the exhaust out of the way

Lower link 1130mm

Diff End separation 220mm

Chassis end separation MAXIMUM 120mm (advantages of less?? or stick to the maximum?)

Upper link MAXIMUM 970mm (does it need to be this long?? can i or should i go shorter??)

Cheers in advance for any help.

[MART]

No not stirring mud 4b , just interested in different concepts , I was going to do something similiar with mine and was discusuuing it with garth , as he was going to use it on his truck , but in the middle and it actually ended up that the suspension would bind when travelling it so we went for single link , I still have the mount on the diff where we removed it , it now carries a spare link pin bolt , Cheers Paul.

[Nelso]

OK so i've worked out most of it, made the diff end bracket and sorted out my clearances. This now means that i'll have to install the turbo to move the exhaust out of the way

Lower link 1130mm

Diff End separation 220mm

Chassis end separation MAXIMUM 120mm (advantages of less?? or stick to the maximum?)

Upper link MAXIMUM 970mm (does it need to be this long?? can i or should i go shorter??)

Cheers in advance for any help.

There is a 3 link calculator on Pirate.

http://www.pirate4x4.com/forum/showthre ... calculator

[Tapage]

No not stirring mud 4b , just interested in different concepts , I was going to do something similiar with mine and was discusuuing it with garth , as he was going to use it on his truck , but in the middle and it actually ended up that the suspension would bind when travelling it so we went for single link , I still have the mount on the diff where we removed it , it now carries a spare link pin bolt , Cheers Paul.

This it's a nice and clean setup dude . I just choose ( IMOP ) heim jonts for more flex ..

[chunderlicious]

heim joints wont always give more flex, in most cases they dont flex any better. if the links converge too much then when you put on the brakes the car will rise. same as when you accelerate up a rock with only the front wheels on it. it will raise the body and leave the diff behind till the flex maxes out.

i believe in the 75 percent rule, dont know if anyone else does. (upper links 75% of lowers) same as 4 link rear.

and how often are you going fast when the diff is cycling through flex? and if you are going that fast while using all the flex, vibration in the steering will be the least of your concerns.

[sierrajim]

OK so i've worked out most of it, made the diff end bracket and sorted out my clearances. This now means that i'll have to install the turbo to move the exhaust out of the way

Lower link 1130mm

Diff End separation 220mm

Chassis end separation MAXIMUM 120mm (advantages of less?? or stick to the maximum?)

Upper link MAXIMUM 970mm (does it need to be this long?? can i or should i go shorter??)

Cheers in advance for any help.

There is a 3 link calculator on Pirate.

http://www.pirate4x4.com/forum/showthre ... calculator

Cheers mate,

That's a rear end calculator. I'm also mathmatically retarded.


So if the links are converged at the chassis end the front will squat under accelleration and jack under brakes?

I could clearance the floor a little and get maybe 40mm more separation at the chassis end.

The car is being run in Winch type events so there is a little bit of speed involved.

[Red_Zook]

i believe in the 75 percent rule, dont know if anyone else does. (upper links 75% of lowers) same as 4 link rear.

im agreeing with this...
i did this in mine... well it looks right anyways

[Bad JuJu]

Checkout the Claytons long arm kit for Jeep Wrangler TJ, a pic can bee sen here of that (also a materials list and lengths) http://www.ultimatejeepstore.com/script ... oduct=1252

IS this the type of setup you mean ?

[lukes4x4]

i`d go with option 1, make the upper as close to the lower arm length. nissan rear trailing arm bushes, they flex huge on the my buggy, and cause heim joints are illegal. keep the seperation on the chassis end as close as possible to the diff end , other wise castor issues will be a common thing. you will want to run a good swaybar and dampener as well otherwise front end wobbles start at 40kph guaranteed....

Cheers luke..

[sierrajim]

Looks to be all sorted. Have the upper link being made now (Thanks Mr Cheezy ).

Diff end bracket, new panhard brackets and chassis prepped for the pending arrival of the link so i can build my chassis end bracket then i can get these damn coilovers in. Then its mounting the turbo so i can have the exhaust redone to clear the upper link.