New 15 All Terrain control arms ?

Robert.jean1 · July 22, 2015

Short box is 69.3" floor length and 78.8" floor length for standard box.

thefishhawk · July 22, 2015

Are the aluminum control arms natural silver or painted black? My 2015 4wd High Country crew cab short box (ie not Z71) has black control arms. I assumed this meant they were steel, but now I need to check them out with a magnet to make sure.

my 14 CCSB Z71 4wd are natural aluminum colored.

robvas · July 22, 2015

2014 DC Z71 4x4 Silverado - steel

2015 CC 4x4 GMC - steel

Neither of my trucks had the aluminum control arms

LSXTC · July 22, 2015

'15 CCSB 6.2 and I got steel control arms.

Steel or aluminum makes no difference, honestly. They are the same darn thing and components fit them the same ways. The difference is that with the aftermarket parts the manufacturers say that they wont work with aluminum control arms because of liability. They are worried about torsional stress fractures of aluminum when changing suspension geometries and such. It's totally up to the consumer whether they want to install parts on an aluminum control arm or steel....the parts fit the same.

nadrojcote · July 22, 2015

'15 CCSB 6.2 and I got steel control arms.

Steel or aluminum makes no difference, honestly. They are the same darn thing and components fit them the same ways. The difference is that with the aftermarket parts the manufacturers say that they wont work with aluminum control arms because of liability. They are worried about torsional stress fractures of aluminum when changing suspension geometries and such. It's totally up to the consumer whether they want to install parts on an aluminum control arm or steel....the parts fit the same.

Are you sure? I was under the impression that the steering knuckles were different between aluminum and steel and that's where the issues come from.

The 2014 GM ½-ton trucks come with either aluminum or steel upper and lower control arms and knuckles. It seems to depend on bed/cab configuration. Fabtech’s Riley says, “The suspension types can be mostly identified by cab and bed configuration per GM. That has seemed to hold true for the most part by the reports we are getting from the field. The main difference for Fabtech between these two types of suspensions is the different ball joint tapers. This affected our steering knuckles and tubular upper control arms from the ’07-’13 model. On our steering knuckles that go into our 6-inch systems we are machining different tapers for the aluminum suspension. The steel version still used the ’07-’13 ball joint tapers. For our upper control arms, we had to develop a new ball joint specifically for the aluminum suspension while the steel version utilized ’07-’13 ball joints. Same goes for our Uniball pins. We built one specifically for the aluminum suspension.” On the topic of steel and aluminum suspension parts, BDS says, “There are some variances from the aluminum to steel arms that require separate kit listings to fit the individual ball joint and tie-rod tapers.” Skyjacker notes, “Trucks equipped with the aluminum suspension components require a specially designed steering knuckle to properly fit the ball joints in this application.”

From: http://www.fourwheeler.com/product-reviews/1401-2014-gm-12-ton-suspension-systems-raise-the-roof/#ixzz3gec5uQw8

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This is why when I replaced my ball joints with moogs the taper didnt fit right and I had to return them. The aluminum setup uses a larger taper on the ball joint and larger mounting holes on the steering knuckles.

Heres a picture of a moog balljoint (07-13 style w new integrated boot) beside a 2014+ aluminum ACDelco ball joint.

When I installed them the moog ball joint was loose inside the steering knuckle.

TxTruckMan · July 22, 2015

the pattern is cc short box (5.5") get aluminum control arms and all double cab and cc reg box (6.5") get steel ones...Z71 does not matter it can be either 4x4 or z71

I have CCSB with steel.

LSXTC · July 22, 2015

I guess at this point I'm not surprised by anything. GM seems to have multiple variants and combinations.

Let me put it this way...I know a guy with an aluminum control arm truck and he fit parts that supposedly wouldnt fit. All a direct fitment, so I don't know what to believe as far as product compatibility goes.

Looking at the GM parts breakdown all the parts show to be the same. It's confusing as heck.

nadrojcote · July 22, 2015

I think you're confused with how the front lower control arms connect, they have no direct connection to steering knuckles.

The control arm attaches to the chassis via two bolts and some bushings and mounts. The control arm mounts the spindle via a ball joint. The spindle bolts to the steering knuckle.

All parts are the same. The only different part numbers between the aluminum vs steel front end are the control arms themselves. The parts all work together. If you want to swap to a steel control arm, only the control arm is required to do the swap.

Again, it's a liability thing. Steel is stronger than aluminum. When suspension geometries are changed there is more stress on control arms. Aftermarket vendors don't want liabilities tied to failure of aluminum control arms so they just list them as not being able to work with the aluminum variants.

Sorry, but you're wrong. I know from first had experience as per my pictures. Steering knuckles and spindles are all one piece.

TJay74 · July 22, 2015

2014 Sierra AT CCSB 4x4 Z71 and mine are Alum.

ih8ford · July 23, 2015

2015 ccsb z71 alum arms

Spurshot · July 23, 2015

Sorry, but you're wrong. I know from first had experience as per my pictures. Steering knuckles and spindles are all one piece.

The GMT900 and K2 have steering knuckles with a large hole to allow the separate spindle (hub) to fit into and allow the 4wd front half-shaft to pass thru.

nadrojcote · July 23, 2015

I've always known a steering knuckle to be aka a spindle. Same as on a snowmobile. A hub is a hub, a steering knuckle and spindle are the same thing. I could be wrong I usually am, but what I was getting at is that the steering knuckle is different with different sized holes for the ball joint tapers between aluminum and steel. This is where the difference lies.

SouthernSilveradoGuy85 · July 23, 2015

I've always called a knuckle as the 4x4 or FWD version with a hole for the axle and a hub bolts to and then a spindle for a 2wd or RWD where the brake rotor slides over a cone.

For me:

Knuckle

Spindle

FL335i · July 23, 2015

2014 CC/SB LT 4x4. Aluminum arms. My Co-worker has the same year color etc truck, but is 2WD Z71, Steel arms.

Spurshot · July 23, 2015

I've always known a steering knuckle to be aka a spindle. Same as on a snowmobile. A hub is a hub, a steering knuckle and spindle are the same thing. I could be wrong I usually am, but what I was getting at is that the steering knuckle is different with different sized holes for the ball joint tapers between aluminum and steel. This is where the difference lies.

I've referred to the shaft portion where the bearings go as the spindle. The rest of it, I've called the knuckle. I always envision a spindle as a shaft that something spins on. Get a Brit involved in this conversation and we'll really get confused.