Bolt on front end 4 link possible?

[nukegoat]

Since you're the poster I generally associate with complicated, high-speed suspension links/geometries, there's a question I've always wanted to ask you - what can I go read to learn about this topic? All the google results are about how one puts in a rear triangulated four or three link or whatever, but not why I'd want one or how they differ from what I have. I sincerely admire your fabrication skills, so I thought I'd ask.

Thanks for the complement! All the info you need is around you but the hard part is filtering out the 40% or so thats garbage. Start with good fundamentals. Try to understand foundationally what instant center, roll axis, etc are. I had to read the textbooks to get the basics down. Aim to understand what provides proper street handling first.

Tune to win by Smith is good.
https://www.amazon.com/Tune-Win-science-development-tuning/dp/0879380713

I preferred reading this, though:
https://www.amazon.com/gp/aw/d/0912...f_5?ie=UTF8&psc=1&refRID=E4RCK2ZCZYQSPFCNKWNE

 

[nukegoat]

BillaVista.com - Offroad & 4X4 Tech Articles by BillaVista

I love BillaVistas articles but there isnt really one for suspension design in there.

 

[GW Nugget]

Why not go a bit more simple with a bolt on adjustable Ylink set up? Use a bolt on front bracket like pictured above or a Superflex bolt on bracket. But do it in a way to retain the tie rod in the rear.

 

[jcardona1]

Why not go a bit more simple with a bolt on adjustable Ylink set up? Use a bolt on front bracket like pictured above or a Superflex bolt on bracket. But do it in a way to retain the tie rod in the rear.

That's essentially the setup Nukegoat is running

1995 fzj80 aka "Marshmallow" - 4-link front, 5" lift, 36" km2s

 

[jcardona1]

And duggy's SAS 100

duggy's build thread: 1998 Land Cruiser #SAS100

 

[the stig]

Aghh, every time I read these threads you guys make me second guess buying a lift kit for fear that my cruiser will handle like crap and make terrible noises!! LOL

That will teach me not to read the conversations between suspension gurus. But seriously, is the Slee 4 inch lift kit with DC drive shaft and all the goodies not going to address all the drive line concerns? Realize, I am not trying to go rock crawling necessarily. Just want to put a lift on and make the truck road trip and trail ready.

 

[DylanICON]

The 80 could benefit greatly from a system like this. its not an easy packaging project but it looks like they did a good job on the Patrol.
radius arms are a compromise when you go over about 7-8" of travel due to castor change through travel. instant center is also a big issue when lifted. On our Ford Superduty kits we address IC when we go over 2.5" of lift and also do a 4 link conversion for all the same reasons.

On the discussion of bind: Length of the IC is very much related to how quickly bind accumulates and castor changes with travel. On a radius arm the IC is a physical point at the back pivot of the radius arm. on a 4 link the IC is a virtual point that is MUCH longer so the adverse changes in both bind and castor accumulate much less throughout the travel.

 

[GW Nugget]

That's essentially the setup Nukegoat is running

1995 fzj80 aka "Marshmallow" - 4-link front, 5" lift, 36" km2s

@nukegoat never posted up any good undercarriage pics that I know of... also if I remember correctly he went to a 3link set up.

 

[DylanICON]

y

Why not go a bit more simple with a bolt on adjustable Ylink set up? Use a bolt on front bracket like pictured above or a Superflex bolt on bracket. But do it in a way to retain the tie rod in the rear.
View attachment 1312043
View attachment 1312001
View attachment 1312040

these set ups do allow castor to be adjusted easier but the IC is the same so castor change through the travel is still the same
the extra flex comes from bushing compliance deference with the components used.
drill some holes in the stock radius arm bushings so they flex more and it would articulate more. draw back is it tends to roll the axle under hard breaking and gets wandery under hard breaking if you don't start with a ton of castor static

Edit:
I just noticed in the upper right corner of the picture it appears the cut the original mount off the frame and made it longer. this would change the IC but it is still a Radius arm

 

[inkpot]

Why not go a bit more simple with a bolt on adjustable Ylink set up? Use a bolt on front bracket like pictured above or a Superflex bolt on bracket. But do it in a way to retain the tie rod in the rear.
View attachment 1312043
View attachment 1312001
View attachment 1312040

Have seen the Superflex setup on the trail a lot, not really impressed for the $$$.

 

[AutoCraft Aus]

4 link works well, but for the effort a bolt on has for an 80 is to many compromises over using 12s with standard arms.

This truck has had this 4 link with panhard since about 1999, after having flipped radius arms before that.

It uses the lower original chassis mounts. It has spaced bump stops, and 12" stroke shocks, so effectively with stock bump stops could run 16" stroke shocks and allow that to still have more flex available. [truck runs 38s for play and 35s for "overlanding"]

This truck will drive to almost full flex in 2wd normally, due to how easily the travel comes with this set up.

The sway bar in this one has been specially made and is like the rear a little now, connected to the chassis a bit like the rear and runs down with the arms, across the front diff housing, instead of the opposite with a standard 80 front set up [this truck is an 80 chassis, 75 body, 79 front, 512 c.i injected big block]

We have been working on this kind of set up with 16s front, and using a rear a frame that replaces the upper arms, with 1 foot longer lower arms and 17s in the rear. We have 17s here to experiment with this rear set up in an 80 we have here specific for the purpose of doing both front and rear in the one vehicle, to maximise its travel, but it wont be bolt in At a max 3" lift, with double slinky coils to stay captive in the rear, and coil over fronts.

The coil over kit goes in the coil position, and has the axle forward 1.5" as well to clear 38s to the firewall with a little work. Adjustable 4 links also can give more with a new panhard rod design to make more clearance.

For the record, the patrol needs the 4 link more than the 80, [check the pic of the patrol 4 link, and its seems you need your shocks undone to get it flexing ] as it takes alot to get 12s to work in the front of a patrol, where as 12s work with standard arms in an 80. [my patrol in around 2006 with 12s and 14s triple bypasses on 37s with drop boxes and all the other stuff patrol needs to work]

The other thing with patrol and its huge front diff, is heavier control arms hjust add to the unsprung weight....

12" fronts standard 80 arms, 2 deg bushes, washer mod, sway bar spacers.

Ideally we just need fiberwerx or someone to make some new fenders with 3" lift front and 2" out, and rear flare 100mm longer so the axle can go back 2" to leave the doors alone, but the rear fenders can be tubbed and extended so we can run 16" fronts, 17" rears, and 40s on 20's with a under 3" lift. [My red patrol had 1.5" higher and 3" longer standard looking flares to fit 37s in the pic here]

 

[AutoCraft Aus]

I do also think with a redesign, but really needing a well set up housing for the centre support, and flexing ends, an X link style set up with std arms may also be able to work. But the dont in this form drive as well as a 4 link, and caster still a thing.

 

[nukegoat]

@nukegoat never posted up any good undercarriage pics that I know of... also if I remember correctly he went to a 3link set up.

I did post them in some other related thread on relocating radius arms or something.

Ultimately I went to a 3 link to improve my roll axis. I actually preferred the "5" link for durability - i lost a link mount on my 3 link while out on Dusy and i was screwed. With the 5 link you can lose one link and keep going.

The 3 link is far easier to engineer though.