Planar Suspension Questions for Suspension Fabricators

[Perrorojo]

So I have this 53 Willys Wagon. I love it as it is but at some point it's going to get a drive train. It has to have a front suspension upgrade before I can pick which powertrain combo is going in.

 

[Perrorojo]

The Planar uses a transverse leaf in the front but doesn't have a lower control arm. It uses the leaf as the lower control arm. I use "control" loosely because ther is nothing triangulating the bottom of the spindle. As the truck squats under load the spring flattens and the distance between the bottom of the spindle gets longer. This makes the truck turn. Badly. Luckily it has about 60hp and 4.89 rear gears so 50mph is a triumph.

My question is: Couldn't I just fabricate a lower control arm with a similar geometry to the upper and use the spring to support? I have a Vette in the shed that uses a transverse leaf rear so I know it could be done. I really don't want to put a mustang II in it. I doubt it's ever going to have more than 250hp. If it ever gets there it will get brakes, 3-link rear and a complete independent front.

 

[Perrorojo]

Here's a diagram off the H.A.M.B

View media item 87916

 

[Nor'Easter]

No. Leaf springs travel in an ellipse. Adding an additional control arm would over constrain the system and cause it to bind.

To do what you want to do, you would need to use a slipper spring that has no eyes. (Normally they have one for locating purposes). The end of the spring would slide against a surface attached to the knuckle, which would allow a normal control arm system to work effectively.

 

[Perrorojo]

No. Leaf springs travel in an ellipse. Adding an additional control arm would over constrain the system and cause it to bind.

To do what you want to do, you would need to use a slipper spring that has no eyes. (Normally they have one for locating purposes). The end of the spring would slide against a surface attached to the knuckle, which would allow a normal control arm system to work effectively.

I figured I'd have to match the spring path or it would bind. Which would be next to impossible. I was thinking I could do something similar to the 39ford where the spring attached to links that supported. The bottom of the spindle would replace the wishbone in the picture. If I do that I would think I would have to shorten the spring.


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[FSrepair&fabrication]

So if Im looking at this correctly, your problem is the tops of the wheels leaning in because as the spring is loaded it gets longer and pushes the bottom of the wheels out. From the looks of it maybe you could use a set of coilover shocks to stiffen it up, or even air shocks so that the leaf pack isnt flexing so badly. Possibly a truck steering stabilizer would help as well I cant see the whole steering setup but Im going to assume that the toe is changing as well when the suspension travels up and down.

 

[ericlar80]

That has to be the goofiest suspension I have seen. I wonder if a steering stabilizer shock would help?

If you want a lower control arm, then you would have to add a leaf shackle of some sort so as to not over-constrain it. That is if you want to keep that center spring. Seens like a lot of work for minimal benefit.

Me? I would just go straight to a proven front end and ditch this one if I had any intention of keeping it. Especially if I had plans to upgrade the power or let my kids ride in it. Good for parades though.

 

[AMCguy]

Although it’s hard to beat a Mustang 2 suspension based on availability, there’s still a cost factor that I have a hard time getting around.

Have you looked into either an AMC Pacer or Plymouth Volare’ front suspension? They are completely self contained bolt in deals. And cheap if you can find one.

Glenn

 

[gofastwclass]

View media item 87916

This has to be the goofiest suspension design I've ever seen. I can't even imagine trying to drive this with any sort of speed, it looks like camber gain city each time you hit a bump.