Triangulated four link rear ends

[flyingbrick]

Is there anything inherently wrong with this design?

Moving the rear diff out on my safari once its been cut into a ute (soon i hope) and have been considering the change to a four link rear for a number of reasons.

I can make all four arms out of steel to required length with rose joints and all required spacers between joint and factory mounts. Would like to use the factory lower arm mounts on diff and chassis and weld new stronger top arm mounts on the chassis and in the middle of the diff (so the top arms meet in the middle of the diff to form a triangle).

I do not need advice on the cost or correct material selection etc etc just on how well this system works + any tips on getting the most from it in terms of geometry and amount of movement. It seems like a better option than the A arm setups like those that wizzard sell however am sorta wondering why more people do not use it.

-Nathan.

[coxsy]

why the rear suspension works well the front is another matter

[turoa]

Heya mate, ill just add a few of my 2c from my experience with 4 link rear ends.

Have a quick glimpse of this first http://www.pirate4x4.com/forum/showthread.php?t=168577

Also have a look at the 4 link calculator which is somewhere on pirate.

I at first never understood all the link angles and anti squat etc or how to use the calculator, but after just doing it and having a few bad charecteristics I decided to redo the top mounts on mine (its in a hilux tho). I used the calculator (which is really easy to use) and have now got around 90% AS. I havnt been able to use it offroad yet but will be this weekend.

4 links are very strong and easy to build. I think they are a better system than a frames personally. As long as you plan it out you should end up with a very well functioning rear end.

BTW, don't bother with rose joints. They will flog out pretty quick. I run GQ rear bushes (metalastic) for both the top and bottom arms and they well outflex the 12" shocks I run (would go longer but I have no money).

With a 4 link rear end and leaf front I can drive up to here on a ramp



Any q's just ask

[flyingbrick]

Thanks heaps- Will read that link when i get home tonight

#### the flex you have back there is unreal

the rear is OK on the GQ coxsy. The question was more of a whynot?. Spring perches and panhard rod mount + everything else needs to be moved back atm along with buying adjustable rear panhard. Started to think #### its only a little more work for a 4 link rear and its going to mean the axle is in the middle the wholetime.

[rokhound]

Do lots of reading and homework on it. You have to really understand how antisquat and instant roll centres affect the handling characteristics of your rig.
I would like to see someone do this to a GQ as I believe they have a shocking designed suspension. It may well be comfortable and pliable, but the characteristics they show (especially on shorts) is not good. They are very prone to massive wheel hop on decent climbs, and I believe this is due to the fact that the AS numbers are too high.
When the AS numbers are over 100% the arse end bites down into the ground which lifts the front, but the bad part comes when the rear unloads and bounces back up, then the front drops and bites, just as the rear is biting back in again. This induces really bad wheel hop,(exaggerated by bigger tyres) and it is more than once that I have seen one of these rigs go over backwards on climbs.

So , do your homework, and do it right. I also suggest that you build in some adjustment on the upper arm mounts at the chassis end as this will enable you to dial in what you want it to do. Mine has adjustment from low 60% to middle 90% numbers for AS.