Aluminum / XFE NNBS Front Suspension Rebuild

[Marky Dissod]

aluminum control arms are double to triple the price of my steel OE parts!
Would like to get rid of weight for all the right reasons, but I don't know
if the initial investment is worth it?

Are better handling and/or better MpGs are not really all that appealing?

Anyone have any idea how much longer the aluminum parts last compared to steel parts?
If they cost 3x more but they last 3x longer, it's a win.
If you buy another aluminum replacement kit before the price goes up, it's a bigger win.

 

[Scrappycrow]

While the control arms might be 2-3x as much, a quick look at Summit Racing shows the stock knuckles at $275 each and the aluminum knuckles at $85 each. Yes, the knuckles are not a wear item, but if you're going for weight reduction (particularly unsprung weight), spending under $200 might be a good value, depending on whether one can (as I mentioned earlier in the discussion) sleeve or ream the knuckles if you want to stick with the cheaper steel arms.

@petethepug, will you be weighing the parts and listing the results component vs. component? If so, I'd like to ask you to weigh the arms not only by total weight, but by inboard (at the bushings) and outboard (at the ball joint) so we will know the unsprung weight reduction, not just the total reduction.

 

[mikez71]

Dang new knuckles are just $85 a piece? I wish I went aluminum.
Those steel lower arms are pretty heavy!

For unsprung weight comparisons, I've heard of people counting half the weight of the arms as an estimate.

 

[Foggy]

While the control arms might be 2-3x as much, a quick look at Summit Racing shows the stock knuckles at $275 each and the aluminum knuckles at $85 each. Yes, the knuckles are not a wear item, but if you're going for weight reduction (particularly unsprung weight), spending under $200 might be a good value, depending on whether one can (as I mentioned earlier in the discussion) sleeve or ream the knuckles if you want to stick with the cheaper steel arms.

@petethepug, will you be weighing the parts and listing the results component vs. component? If so, I'd like to ask you to weigh the arms not only by total weight, but by inboard (at the bushings) and outboard (at the ball joint) so we will know the unsprung weight reduction, not just the total reduction.

I didn't look at summit for the knuckles. Just at RA.. Didn't see them...
I don't put a lot of miles on my Yukon so a 1 mpg gain isn 't a big deal...
Plus I am towing half the time so mpg sucks so badly... I'll re-evaluate this as
I know that getting rid of unsprung weight is Awesome !!

 

[petethepug]

Good point on weighing in on the parts before & after. I’ll steal the wife’s digital scale and post up some pics.

Haven’t posted info up on the source or pricing of the parts for one reason. Demand drives the price. I found both the aluminum knuckles on Amazon from the GM factory store. I scored with the “not Orig packaging” section for 1/2 off.

P/S Alum Knuckle 22842315
D/S Alum Knuckle 22842314

Purchased them for $45 & $50.14 shipped free w/ prime.

I got both the D/S & P/S Alum upper control arms for $95.99 ship’d free off eBay
22840983
22840984

Keep in mind that GM assigned new part numbers to make it appear as though Gen 4 (NNBS) & Gen 5 front suspension parts were not interchangeable.

If you’re not thorough searching for parts you’ll find that the aluminum UCA, LCA & knuckles are priced as high as $300 ea LOL.

 

[arkie]

Good point on weighing in on the parts before & after. I’ll steal the wife’s digital scale and post up some pics.

Haven’t posted info up on the source or pricing of the parts for one reason. Demand drives the price. I found both the aluminum knuckles on Amazon from the GM factory store. I scored with the “not Orig packaging” section for 1/2 off.

P/S Alum Knuckle 22842315
D/S Alum Knuckle 22842314

Purchased them for $45 & $50.14 shipped free w/ prime.

I got both the D/S & P/S Alum upper control arms for $95.99 ship’d free off eBay
22840983
22840984

Keep in mind that GM assigned new part numbers to make it appear as though Gen 4 (NNBS) & Gen 5 front suspension parts were not interchangeable.

If you’re not thorough searching for parts you’ll find that the aluminum UCA, LCA & knuckles are priced as high as $300 ea LOL.

Can you tell me if these upper control arms will replace my OEM alum arms on my 16 Yukon Denali?
Parts search does not find any OEM alum for my year model and GM parts guys say they have heard of alum upper arms

Thanks for any info you can provide

 

[petethepug]

Yes, the aluminum upper control arms / UCA fit your ‘16 Yuke as long as it is fitted with aluminum knuckles or already had aluminum UCA ….

To run aluminum UCA on a truck not equipped with them you’ll need to swap the existing steel knuckles to the aluminum version. That’s what I’m doing on my ‘09 Esky

The aluminum lower control arms / LCA are interchangeable with steel on Gen 4 / 07-14 / NNBS and Gen 5 / 15-20 whether the truck has aluminum or steel knuckles.

 

[SpyShops212]

It's front-end refresh time. I'm fast approaching 180K miles on our 09 Esky ESV. It has the original everything on the suspension. The front sway bar bushings have been replaced with poly recently because they were ready to disintegrate. While looking around at parts I saw that aluminum upper and lower control arms were an option for 07-14 / NNBS full size SUV. No info really nailed down who, what, why, when and where aluminum was used except little snippets on the interwebs.

@iamdumb did nail it here ...



In 09 GM offered the XFE package for 2WD Tahoe that included bits and pieces of aluminum suspension and a spare tire rim. The Hybrid, PPV & SSV also got a bunch of aluminum parts as well as odd ball trims. I'm interested in using both upper and lower control arms made of aluminum because the Esky has boat anchor 22" rims. GM boasts that using all that aluminum on the XFE gives it a 1 MPG increase and takes 32lbs off each side of the front end. I figure that by the time I get the Brembo BBK installed each front corner will have at least 40lbs shaved off.

IN REGARD TO NNBS TRUCKS ...

View attachment 418997


So, on to the differences in forged & stamped steel as well as aluminum NNBS control arms that have been buried for so long.

* 2016-2017 stamped steel control arms have been recalled by GM for inadequate welds near the control arm bushing that may allow it to separate. Just ditch them.
* The forged steel upper and lower control arms for our 07-14 NNBS SUV are also used on the next Gen 15-20.
* The aluminum upper and lower control arms from select 07-14 NNBS SUV are also used on the next Gen 15-20.
* Both the forged steel and aluminum hubs from select 07-14 NNBS SUV are also used on the next Gen 15-20.
* In 1500 Pickup Trucks 07-13 were always cast steel, 14-16 had all three and 17-18 were always aluminum.
* Aluminum lower control arms can be run on any 07-14 NNBS Tahoe / Yuke / Burb / Esky.
* Only the aluminum upper control arms have a specific ball joint. The stamped steel and aluminum ball joints are not cross compatible.
* Aluminum upper control arms must have aluminum hubs to accommodate the difference in taper of the aluminum specific ball joint.
* The lower aluminum control arms are cast aluminum. The upper aluminum control arms are forged.
* Products in the control arms contain chemicals known to the State of CA to cause cancer and birth defects or other reproductive harm.
* The thread and pitch on all ball joint studs for both aluminum and steel are identical.

As the parts are ordered and arrive, I'll post up the source and pricing. I'm in the parts procurement phase and the work will be carried out by my trusted diesel Indi tech. The Esky is my daily and I'm over stressing out about getting a job done so I can drive the vehicle the next day.

Anyone know if the aluminum control arms have any torque to yield bolts that may be specific to them?

The Duralast Gold upper and lower control arms are the best for your truck. They have grease fittings and lifetime warranty. If the part ever fails you can walk into any autozone for the rest of your life and get a new one. They are a little more than OEM but are made so much better. If you look at the parts you will understand what I am telling you. I changed my control arms in my 2008 60k miles ago and the new owner says there is no issues. I would do the sway bar and end links OEM also the outer tie rods. The hub bearing should also be OEM too.

 

[rmuszynski]

any opinions on replacing entire lower aluminum control arm versus just replacing the ball joint which is bad (per MD inspection)? Seems like pressing the old ball joint may be more trouble than its worth. Hoe has 250k miles.

 

[petethepug]

Sent you a IM w/ info

@rmuszynski