3 Link Prototype...

Hello All,

looking for some input here. I am contemplating engineering and designing a "budget" 3 link set up for the rear of my 2014 Screw. At the moment it would not be designed to gain much travel...but rather to check suspension geometry and ride quality. The long travel would likely come later.

Instead of going with a bed cage / rack and bypass shocks with coil-overs...what do you think about just a set of coil overs from the front?

This is just a pre-cursor to eventually doing a long travel rear 3 link and I am just looking for info.

Would the spring rates on the front coil overs be too high as they are designed to support engine etc. and not just an empty bed?

I know Giant Suspension makes the DDL kit...and it's nice...but at around $18k...it's a bit much. I am trying to initially link the rear reliably for under $8k without having to move the fuel tank or re-configure the underside of the truck.

Any thoughts or input appreciated.

If anyone can see a reason why this 3 Link design wouldn't work (as compared to a standard 4 Link)...please chime in. (Panhard bar not illustrated)

Maybe I am missing something obvious...but the geometry seems to work.

*Angle values are strictly for demonstration purposes and can be adjusted in real world conditions.

I just want to know if this would work...overall. I'm fairly certain it would...but extra sets of eyes may pick something up that i am missing.

Again...any input appreciated.

IMO it's be easier to run a reverse 3/4 link, you can still keep the stock tank, but your looking at a lot of fab work and cycling to get the upper links to work.

A.I.I.Raciing said:

IMO it's be easier to run a reverse 3/4 link, you can still keep the stock tank, but your looking at a lot of fab work and cycling to get the upper links to work.

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I appreciate the input...however...all that fab work is what I am trying to get around...to keep cost low.

By the way...this is not something I plan on marketing...I just like to be different (as is obvious by my exhaust set-up).

The 3 link parts are available readily and are mostly bolt-on. Fixing the rear end to the lower link arms would be the only fab work.

I am curious about the geometry and whether or not coil overs from the front would work well enough?

Cheers.

I'll be honest... I don't get the diagrams.. but to answer your question, coilovers/bypass shocks generally have to be "heavier" in the rear of a linked truck because they are positioned on the lower arms where they are subjected to increased leverage.

1ntheoc said:

I'll be honest... I don't get the diagrams.. but to answer your question, coilovers/bypass shocks generally have to be "heavier" in the rear of a linked truck because they are positioned on the lower arms where they are subjected to increased leverage.

Click to expand...

I tried to illustrate the difference in U-joint angles with the rear end fixed to the lower arms (3 link) and non-fixed (4 link). The control arms are not illustrated...only the rear end orientation at normal ride height and full droop.

The 3 link, in theory, would maintain rear universal joint at zero degrees...whereas with a 4 link...both universal joints are articulating at full droop.

But the info about rear coils helps...thanks.

You're never going to be able to do anything like this without "all that fab work". These things don't just mystically fall together and function.

Steele16 said:

You're never going to be able to do anything like this without "all that fab work". These things don't just mystically fall together and function.

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There is a kit like this available but it uses air shocks to keep the rear end housing on an even plain...which to me...is just another potential mechanical failure point.

I realize that some fab work will be involved...but only to locate the rear end housing to the lower arms. The rest is bolt-on and has already been engineered and proven.

Again...my main query is whether someone can spot a problem with geometry that I may have overlooked bearing in mind that angle values are not exact but rather just to illustrate the point of keeping the rear end housing on the same plain as the lower arms.

You're basically building a ladder bar setup, like a drag race car. In my experience there is very little articulation in those setups.

Steele16 said:

You're basically building a ladder bar setup, like a drag race car. In my experience there is very little articulation in those setups.

Click to expand...

Well...not really.

A ladder bar set-up implies inter-connected upper and lower arms that connect at a single point on the frame.

I am talking about a 3 link...lower arms and a panhard bar.

Less articulation...yes...but that is what I am questioning. Is less articulation of the rear end a limiting factor? I can't see how it would be...as it maintains almost zero degrees on the rear universal joint...the limiting factor (as far as I can see) would be the forward universal joint.

Ok...let's re-phrase the question...

If I took a Giant Suspension Daily Driver Link kit and eliminated the air shocks and hard mounted the rear end to the lower arms...would it work?

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