Brett W’s City Goblin – 09 SS Donor #229 v1

Brett

Well-Known Member
At this point I wouldn't order any control arm for a TC that isn't a GM part. I don't think anyone has found an aftermarket that will work.
ZZP would be the official aftermarket source for the lower control arms with the proper ball joints.
 

Brett

Well-Known Member
I think even the ZZ Performance ones are GM, at least they say "stock".
I honestly don't know. However, they are a performance outfit and understand the cobalt. You can select the 20.5 mm ball joints.

No matter what, I would measure the ball joint stud to make sure I get the right one.
 

r3drckt

Goblin Guru
They sell aftermarket ball joints by themselves as well. You drill out the rivetted ones and then bolt the new ones to the control arm. If you can get a new aftermarket one for $60 and the correct ball joint for $20, still cheaper than the $130 for GM part.
 

Gtstorey

Goblin Guru
I didn't have any luck with buying the ball joints separately either, the ones I got were the 20mm, not 20.5mm. I'm sure there are some 20.5mm out there, but it seems hit or miss getting the right ones.
 

Gtstorey

Goblin Guru
I've went back and looked at the previous post discussing this and saw your pictures again. It just didn't match what I received, 20mm. Maybe mine were the odd ones or maybe they were counterfeit (bought through rockauto) but they didn't work with my hubs. Since the listings seemed to indicate that they were more likely to be the smaller size, I just returned and ordered the whole GM arms.
 

Brett

Well-Known Member
The Great Ball Joint Dilemma

For our new readers / builders, a little background. I built a Goblin based on a 2009 Cobalt SS. This is the turbo charged model and turbo SS’s utilized a different size ball joint, specifically the stud diameter than all other Cobalts. Specifically, the ball joint size for a TC Cobalt is 20.5mm. The size on all other Cobalts is 19.5mm.

My doner had 167k miles on it and during my build, I opted to replace my lower control arms with new arms from Rock Auto that I believed had the correct ball joint stud size of 20.5mm. As it turns out, they were 19.5mm. Due to this and many other factors, while test driving my Goblin, I ended up sliding into a parked Dodge Intrepid and slightly bending my frame.

Now, onto the dilemma.

After searching high and low, I have come to the determination that the proper size ball joints are no longer available, either individually or on control arms pre-assembled.

Things I have done to find the proper ball joints or control arms:

-Placed orders with 11 different online stores for the control arm that I need. Most of these stores were GM dealer parts departments that are using the same backend systems but branded for their stores. All orders were canceled within 48 hours due to long lead times.

-On of the local Goblin guru’s is a commercial mechanic (title does not due him justice). He was able to utilize a system that checks parts departments nationally for the specific part that I need. None were located.

-Sweet talked the local Autozone manager to allow me to measure every ball joint / control arm they had for Cobalts. While he did not appreciate my sweet talking, he was understanding of my dilemma and allowed me to rummage through the warehouse unsupervised and measure ball joints. None were located that were the correct size. Side note, this Autozone is billed as “the largest in the South” and acts as a regional warehouse for other stores so I had access to more inventory than your typical autozone.

-Placed an order with Summit Racing for the correct control arm. They have pushed the expected order delivery date to October. Due to this, I called them and they were nice enough to put me in contact with ACDelco. I have kept this order open, however my expectations are low that the order will be fulfilled due to the next item.

-Spoke to ACDelco that indicated the control arm that I need has been discontinued.

-Reached out to Powell racing and ZZP who both informed me that they are unable to get the ball joints or control arms for a TC with the proper ball joint size.

-Contacted Moog and with great patience and persistence, was put in contact with a parts guru / engineer. We spent several hours going through CAD drawings and determined 2 things. 1) they do not currently make a proper ball joint for a SS/TC Cobalt, 2) That all dimensions for the drawings were in metric. I find the dimensions interesting because some people keep quoting the ball joint size in imperial (freedom) units. Nothing wrong with that, but I will stick to the metric units for ball joints on a Cobalt / Goblin.

-Placed an order for every ball joint listed on Rock Auto (as of March 2021) for a 2009 Cobalt, both SS and NA. None of the 14 ball joints were correct.

-I have one ACDelco control arm with the correct ball joint. It was manufactured by Central Corporation out of Taiwan. According to their website, the minimum order quantity is 1000 units. While this is compelling, I don’t want to be in the TC (and HHR SS) control arm / ball joint business.

At this point, I believe I have determined that 20.5mm ball joints (or the proper control arm) is now unavailable. While I haven’t canceled my order with Summit, I believe that it will eventually be canceled once they determine that the part is no longer available.

For those wondering, I am trying to track down ACDelco 25930724 which is a passenger side lower control arm for a 2009 Cobalt SS.

Unless someone has the proper part sitting in their garage (let me know if you do and are willing to sell), I am to the point of finding the knuckles off of a standard Cobalt and using the 19.5mm control arms that I already have.

Fortunately, my local self service junk yards have many Cobalts to chose from. As far as I can tell, the main difference is the ball joint hole and the steering geometry (which doesn’t matter in our application).

I am open to thoughts and options from the community.

Also, I have talked to Lonny and he is also looking into options.

Till next time.

Brett
 

Ark :D

Goblin Guru
If you go with knuckles from a non SS/TC, you also need a different pair of rear brake adapters from Adam/Lonny.

Ask me how I know!
 

ATMironov

Well-Known Member
So I recently ordered new Moog control arms with ball joints, model # RK620898 and RK620897.
I just went into the garage and measured them, and they measure 20mm. The knuckle opening is measuring 20mm also with plenty of room for the bolt to squeeze it together.
Have all the ball joints you received been 19.5mm exactly?
IMG_8412.jpg

If you change knuckles, I believe the splines are different in the hubs.. not sure if a TC hub will fit in an SC knuckle so you may need custom axels too.
 
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Brett

Well-Known Member
They were all under 20. Typically between 19.4 and 19.8 with a few outliers.

While I might be making a mountain out of a mole hill on this one. After all I have been through, I need it to be right.
 

ATMironov

Well-Known Member
They were all under 20. Typically between 19.4 and 19.8 with a few outliers.

While I might be making a mountain out of a mole hill on this one. After all I have been through, I need it to be right.
It’s definitely got me looking now.
It looks like the FE3 suspension came with 19.94mm ball joints (probably what I have) then there is the 19.5 from the SC and 20.5 from the TC.

@Lonny is developing a new rear control arm and upright.
This would fix the problem.
 

Brett

Well-Known Member
It’s definitely got me looking now.
It looks like the FE3 suspension came with 19.94mm ball joints (probably what I have) then there is the 19.5 from the SC and 20.5 from the TC.

@Lonny is developing a new rear control arm and upright.
This would fix the problem.
If your hole is 20mm and your ball joint is 20 then I wouldn't be too concerned.

I've seen some initial prototypes of the rear suspension and it looks great but DF is in production catch-up so it has been put on the back burner while they get caught up. They have been so helpful that I cannot ask them to get it completed for me.
 

Gtstorey

Goblin Guru
Depending on how much you want to keep trying, crate engine depot has them shown as available as do several online gm parts suppliers. There are probably still some floating around if you keep digging. There's always one someone has sitting on shelf somewhere.
 

Brett

Well-Known Member
Depending on how much you want to keep trying, crate engine depot has them shown as available as do several online gm parts suppliers. There are probably still some floating around if you keep digging. There's always one someone has sitting on shelf somewhere.
I spoke to Crate engine depot a few weeks ago. they just order from one of the big suppliers and they dont have any in stock. Most of the GM Parts suppliers utilize GM's part ordering system. I placed orders from many of them and they were all canceled within 48 hours. Most of the cancelations came from the same person, Carl.
 
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