Stock control arms: Steel or aluminum?

[TX14Z71]

"Over the years, many control arms have evolved from their humble stamped steel beginnings to elaborate cast aluminum pieces that are stronger and lighter than ever before. Being cast aluminum, they don't corrode quite like the steel control arms do, but since aluminum is a softer metal, they do bend and crack when things go wrong. This means that simple fender-benders or pot holes can potentially damage them, throwing the alignment way off."

[pancepance]

Did a test drive and inspection yesterday.
The control arms on mine are Steel. Not sure how that plays into all the others but for the record. This denali at least, has steel.

[racerkvn]

I was begining to believe it was the early production Z71's were steel control arms and they were making an advancement to using alum on the later release Z71's but from this, there really seems to be no rhyme or reason... I wish somebody FROM GM would chime in with reasoning for the mixed bag of control arms.

[Jon A]

There seems to be a theme where standard bed trucks are getting steel, short beds are getting aluminum. Mine--standard bed CC Denali with Z71--steel.

[SY2455]

There seems to be a theme where standard bed trucks are getting steel, short beds are getting aluminum. Mine--standard bed CC Denali with Z71--steel.

Well I think that post #48 has it right. Mine is a 6.2 CCSB LTZ 2wd Z60 high performance suspension with the steel control arms.

[05cyclone]

I checked mine and I have the Denali 6.2 SB with the Z71 suspension and it has the aluminum arms.

[never_rested_24-7]

My 2014 Z71 SLT has aluminium uppers, lowers and knuckles.

Edited September 2, 2014 by never_rested_24-7

[Guapoh]

Crew cabs with short beds get aluminum. All others have steel.

[henrypbui]

Has anybody confirmed which models get the aluminum suspension?

[Spurshot]

Has anybody confirmed which models get the aluminum suspension?

 

Yes, the same ones that get steel.

[mfbearded]

2015 LTZ Z71...steel upper and lower... got down, looked and put a magnet to both sides...seemed like the most efficient sure way to tell.

[POS VETT]

Cast iron arms have a black coating/paint. The aluminum arms are bare and silver-ish in appearance.

[robvas]

2014 Silverado Double Cab Z71 4x4 - steel

2015 GMC Sierra SLT Crew Cab 4x4 - steel

2015 Silverado LTZ Crew Cab 4x4 that I almost bought - steel

[Robert.jean1]

Steel may be a little heavier but the strength benefit provided by steel control arms out weighs the weight benefit in a truck that is used for anything considered " heavy duty " work. The trucks like Denali that aren't intended for rugged off-road use I'm sure benefit from the weight savings while traveling down the highway.

[Spurshot]

I don't believe there are cast iron control arms. I know the upper arms are forged steel. I'll take another look at my lowers, but I'd bet on forged steel. Same with the knuckles, forged.

 

Also, the aluminum arms and knuckles look forged to me as well.

 

As for which is better, I'd prefer to have the aluminum...assuming they did a good job designing them. But mine are steel. The aluminum arms should provide better suspension control, better road contact, etc..

 

Also, aluminum will, indeed, corrode. Very much so. Road salts will make it much worse. Keep them clean.

Edited July 23, 2015 by spurshot