Boxing lower control arms

[08Malibu]

I did the 1/2" pipe on the sway bar bolts, but the 2" pipe I was referring to was just a tool for pressing in the bushings.

Got it. Thinking you meant as some type of spacer.

 

[Rt Jam]

Boxing the stock lower arms is a bad idea as they are designed to flex on purpose to prevent suspension binding and damage to the weak LCA mounts on the frame. The rear 4 link suspension relies on control arm flex and bushing deflection to operate correctly. Boxed arms and especially poly bushings induce binding issues. The only way to run box or tube rear arms is to use ones with spherical joints. Also its a good idea to weld on gussets to reinforce the LCA mounts. Even the stock rear sway bar causes binding, which is why the frame mount aftermarket sway bars are better.

I agree with this 100%. The reason you get replies like, I've never had a problem is because the mounts are pretty strong on G bodies but I have seen this EXACT problem on fox Mustangs with the same 4 link suspension. Articulation causes places twisting forces on the mount and when you stiffen the arm and add stronger bushings, that is just more twisting on the mount.

A stamped steel arm will not deflect under compression or tension. Lateral forces will not change their length. The are only meant to locate, which they do, even when made from stamped steel.

 

[Ron_NC]

I agree with this 100%. The reason you get replies like, I've never had a problem is because the mounts are pretty strong on G bodies but I have seen this EXACT problem on fox Mustangs with the same 4 link suspension. Articulation causes places twisting forces on the mount and when you stiffen the arm and add stronger bushings, that is just more twisting on the mount.

A stamped steel arm will not deflect under compression or tension. Lateral forces will not change their length. The are only meant to locate, which they do, even when made from stamped steel.

I hate to post this sorta off topic, but I bought these used. Should I worry about these? ->

 

[scoti]

I hate to post this sorta off topic, but I bought these used. Should I worry about these? ->

View attachment 151464

For mild street driving, they work. They'll just bind (stress the mounting points) sooner than stocker arms might. The more severe the use (abuse?), the sooner things can fail. Solid arms should utilize spherical joints to allow more flexibility before bind.

 

[Ron_NC]

For mild street driving, they work. They'll just bind (stress the mounting points) sooner than stocker arms might. The more severe the use (abuse?), the sooner things can fail. Solid arms should utilize spherical joints to allow more flexibility before bind.

Dang ☹️ Thanks for the reply

 

[08Malibu]

If boxed arms are bad why would anyone “upgrade” their suspension to tubular or boxed arms? All I’ve read over the years is to use rubber bushings over poly.

 

[500/600]

What a ridiculously controversial subject. Box them. Period. Solid spacers if using a sway bar. Period. Solid spacers if not using a sway bar because you might want to later. Period. The arms in the ‘off topic’ picture will work fine. Better than fine. Period. Articulating uppers are better but not that much. Period.
When you ask a question like ‘will this work’ you should know you’ll get more negativity than positive help. So don’t panic out when it happens. Everybody is a pro-mod driver when opinions start flying. Go with what you got and upgrade if you just hate it later. Don’t lose sight of the fun by burying up in the weeds of every discussion.
Go back to the beginning of the thread. Read through post #8. Stop there. And just do it.

steve

 

[fleming442]

What a ridiculously controversial subject. Box them. Period. Solid spacers if using a sway bar. Period. Solid spacers if not using a sway bar because you might want to later. Period. The arms in the ‘off topic’ picture will work fine. Better than fine. Period. Articulating uppers are better but not that much. Period.
When you ask a question like ‘will this work’ you should know you’ll get more negativity than positive help. So don’t panic out when it happens. Everybody is a pro-mod driver when opinions start flying. Go with what you got and upgrade if you just hate it later. Don’t lose sight of the fun by burying up in the weeds of every discussion.
Go back to the beginning of the thread. Read through post #8. Stop there. And just do it.

steve

Thanks,bro

 

[08Malibu]

I’ll add this, and it’s just my opinion on this subject. Metal isn’t supposed to flex. Every time it flexes it gets weaker and eventually will break.

 

[500/600]

I’ll add this, and it’s just my opinion on this subject. Metal isn’t supposed to flex. Every time it flexes it gets weaker and eventually will break.

Sometimes, in some applications. In lots of mechanical applications metal is definitely designed to flex and is tested to do so. It is called 'fatigue cycle' testing. The parts are designed to perform within this fatigue cycle life.
In most cases if something doesn't flex, something with break. The bushing does this job on a boxed arms.