rear control arm removal and installation.

[RustyNCa]

Ok, let's look at this another way... What do modern rear wheel drive with trailing arm suspension cars use?

A Mustang comes to mind. It simply has two upper control arms and two lower but longer control arms. No panhard bar. No clappers.

The only dampener is a shock absorber, one on each side, which serves as a 'bottom limit' when the axle hangs down.

Because the upper arms are shorter, they have a tighter radius (just like your front "A" arms) which causes the axle (or front spindle) to intentionally roll. Notice, your front "A" arms have no clappers or any pivot restrictions.

So, this is not a parallelogram but a trapezoid; a quadrilateral with two sides parallel. All pivot points must be free to move. Restricting motion on one pivot point will have a 'lever' affect on the opposite joint. That's why your mounts are tearing out.

In the illustrations, each pivot point is labeled with a letter for you to study.

With that, I'm done. Do what you want, it's your car. - Dave

Dave you bring up an interesting point about the Fox Body setup, because that was the first thing that popped into my head when you posted the diagram. I'm not sure the length is correct, but couldn't one replace the 58 lower arm with an arm like the Mustang runs? Run one with hiems up front and attached to the axle with the pivot. Pretty much just converting it to a four link?

What made me think of it is the Sebring MX kit car I have to build that runs that Mustang upper and lower control arm setup attached to a solid rear axle of ones choosing.

Cheers
RustyNCA

[Guest]

Thanks guys, plenty of things to think about now.

Dave, true it is my car and basically I'm trying to take in as much information as possible to get to a point of total reliability and more so avoiding something breaking whilst doing 100kph on the hwy with kids in the car and having a disaster on my hands.
Unfortunately I am dealing with a seriously flawed system as you know and one of which I've never seen before so asking lots of questions is the only way to get my head around it.
Trying to build this car on a budget with zero local parts and resources is tough and I'm definitely no engineer.

I appreciate all of help you and everyone else has given me in the last 2 years without it this car would still be a pile of junk sitting in the corner of my garage.

Thanks Chris

[simplyconnected]

Dave you bring up an interesting point about the Fox Body setup, because that was the first thing that popped into my head when you posted the diagram. I'm not sure the length is correct, but couldn't one replace the 58 lower arm with an arm like the Mustang runs? Run one with hiems up front and attached to the axle with the pivot. Pretty much just converting it to a four link?

What made me think of it is the Sebring MX kit car I have to build that runs that Mustang upper and lower control arm setup attached to a solid rear axle of ones choosing.

Cheers
RustyNCA

The fox body uses the back seat crossmember for suspension support, spanning the rear subframe. The center arms are at an angle, like a 45 from the axle to the point of attachment. This eliminates the panhard bar for side loading. For even more insurance, the GT has quad shocks that are mounted horizontally just behind the top of the rear wheels.

To retrofit that to a SB, you would need serious back seat reconstruction because it's wide and tall and heavy metal.

For over 16 years, I beat on my 8.8" 4.30:1 positraction rear end and it never balked. Both 15" rear tires were always in unison as they laid down serious torque all over Detroit and Dearborn. The last set of tires, H-rated BF Goodrich, were not half as sticky as the V-rated Michelins. When the BFs were new they refused to hook. - Dave

[Dakota Boy]

who in Australia (those nosey inspectors) is going to know that a 58 had a one-year oddball rear suspension design? why not install some leaf springs from a 59-60?

[scumdog]

who in Australia (those nosey inspectors) is going to know that a 58 had a one-year oddball rear suspension design? why not install some leaf springs from a 59-60?

Precisely what I thought earlier on in this thread.
Of course getting the rear spring assembly for a 59-60 Thunderbird might be tricky in Aussie!

[Guest]

Dakota boy, I'd be fine if I went to a leaf spring from a 59/60 but as scumdog said it would be impossible to find here.
And to purchase some from the US and get them here would be ridiculously expensive.
Out of curiosity, what's the process of installing them.
Is it just a matter of removing the existing brackets etc then welding the spring perches and away you go.

[Dakota Boy]

my car had leafs installed already when I bought it. Fabricated mounting brackets up front and rear. And the '58 axle housing would probably need the perches added. the leaf springs run UNDER the axle; not above it.

[simplyconnected]

Didn't Australia produce the '59 Ford and Ute, both of which had 2"-wide leaf springs? Aren't those cars domestically supported with aftermarket springs?

Why not take the axles, springs and mounts from those cars and use them on your rear subframe? I have to believe those axles are the same as the Squarebird's 9".

And being all Ford parts, who would be the wiser? This shouldn't require major drama but a simple swap with a little welding. Your choice of aftermarket gear sets run about US$200.00 regardless of ratio. You may be surprised about how easy this swap really is. - Dave

[Guest]

It's actually funny you mentioned that Dave, just been working on the car with my mate, finished and having a beer and we were talking about the exact same thing.
We both came to the same conclusion that it could be a bit easier than first thought.
At the moment I'll get it fixed as is, get roadworthy and registration and then have a serious look into it.
Think outside the box I guess, definitely no shortage of utes in Australia.