Stern vs SPC Adjustable Control Arms

[A4SoftWalker]

Been a while since I've been active on here due to a death in the family. I have been driving my car and its come time to start wrenching and wrap up this project.

I recently looked at my tire wear and my suspension needs more adjustment capability to allow even wear of my tires.
I am comparing at the Stern and SPC brands of upper control arms.
Does anyone have any experience with either OR both?

I am aware that the SPC has the availability of the "Axis Adjustable" bushings or regular bushings. Apart from a bit more noise and control is the harder non-rubber bushing longer life?

Thanks all for your contributions and your vote.


Stern kit



USP Adjustable axis bushing (I'm guessing heim joint?)


USP Standard bushing

[Seerlah]

I remember back in the days the Stern ones would bend on a couple people's cars. This was on the B5 platform and the B6 is heavier. As far as the SPC, they look exactly like the Moog ones (Moog also sells adjustable uppers, iirc). You also have the 034MS option.

I picked up 034MS ones back in the days and decided not to run them. Figured somebody could use them more than me (resold at a discount) as my aggressive driving does not cause significant uneven wear. My Nitto NT555 tires you could not really tell any uneven wear when they retired last summer.If I was to suggest a set, it would be 034MS. Reason being is they use heim joints, have dust boots for the heim joints, and are fully rebuildable. Can't say the same goes for the others, but can be wrong.

The ones I ordered: https://store.034motorsport.com/034m...a6-s6-rs6.html

Another 034 option, but I think these are more track oriented: https://store.034motorsport.com/034m...-b5-b6-b7.html

[agentsmith988]

I'm running these from Rev Motoring. RM is a local dealer here in SLC that fancies up VAG cars before selling them and they have a few aftermarket parts as well. Their adjustable uppers look like knock-off SPC arms as far as I can tell. And they're only $250.

I'm running OEM sport suspension and B5 perches up front (25 1/4" FTG on USP wheels). The outer tip of the UCAs hit the fender well once in awhile when turning and hitting a bump. I pushed the fender liner up a bit with some air tools and it seems to have taken care of it though...

I'm sitting at -0.8º camber and 0.15º toe on each side now. I think the tires will be much happier.

[A4SoftWalker]

I'm 20 minutes from 034 and they for some reason stopped in store local pick-ups.
WHAT?
I've picked up from there for YEARS... I'm mad at them right now.

I guess the Sterns have a rebuild kit as well. Good thinking Seerlah. Also checking out the Moog arms for their track record.
Not sure about the SPC arms having a rebuild kit.

The Rev Motoring arms look suspisciously like the SPC arms... hmmmm. How long have you had them again agantsmith988?

[agentsmith988]

I'm 20 minutes from 034 and they for some reason stopped in store local pick-ups.
WHAT?
I've picked up from there for YEARS... I'm mad at them right now.

I guess the Sterns have a rebuild kit as well. Good thinking Seerlah. Also checking out the Moog arms for their track record.
Not sure about the SPC arms having a rebuild kit.

The Rev Motoring arms look suspisciously like the USP arms... hmmmm. How long have you had them again agantsmith988?

Had them for a few months now. How much you wanna bet the SPC replacement bushings would fit?

[Seerlah]

I would run with what would be the longest lasting with price point making the most sense. With the units with the rubber inner bushings, I assume you can press out the inner bushings and swap them with Lemforder bushings, poly bushings, etc. when they go bad. This is assumption, as you would need to confirm proper size and fitment. Then if the outer ball joint ever gets compromised, you should be able to get the replacement ends after the threaded portion. If a company won't sell just those, that is just poor customer service IMO. I would actually inquire with whatever company you choose if they would sell the outer end if and when it gets damaged and needs replacement.

So break it down...

Stern: $499 w/$160 rebuild kit
034MS: $460 w/$100 or $130 rebuild kit
SPC: $496 w/no rebuild kit listed
Moog: $302 (price is per side, cheaper on Rock Auto) w/no rebuild kit listed
RevMotoring: $250 w/no rebuild kit

While searching, I noticed that there are a number of brands with the SPC design. Not sure who the original designer is, but you have Mevotech and AC Declo selling the same design and around the same price. Another option you can consider is caster and camber kits. You press out the inner bushings and swap the caster and camber kits in. If my memory serves me correctly, K Mac and Whiteline makes them for the B6 A4. You may even be able to find cheaper knock offs on ebay.

[fR3ZNO]

In terms of long life, I would have to guess that the sealed ball joints and rubber bushings would be the best combo (although I've seen cheapo control arm ball joints wear out and develop play quickly). You're in Cali, but I would think in an area like mine with salt on the roads in the winter, I could see the heim joints wearing out due to accelerated wear, even with the dust boots installed.

Considering the SPC/Moog/RevMotoring/Mevotech/AC Delco adjustable uppers all have the same design, must be companies just slapping their name on a product and upcharging accordingly... ie RevMotoring, small company, least markup.

Considering 034 is a different design (billet arms, compared to forged(?)/cast aluminum arms) and has the rebuild kit, I'd probably go with them. Although, those RM arms would be cheap enough for me to give them a shot.

Edit: was doing some research into the SPC arms myself just for shits n giggles, and pulled up this thread: Clicky Click

Something to think about...

[DarkoNova]

Well, damn.

They either bend or have catastrophic failure.

What about Moog?

Probably the same as the SPC arms, but you never know. Rock Auto has Moog adjustable control arms but they don't specify the position on the front (I.E., front or rear upper). Does that matter? Is there a difference or are the front uppers basically all the same?

[Seerlah]

Quality control may have gone up since years past, but biketsai (old section moderator) iirc had his Stern arms bend on the threaded section. With the 034MS ones, there is no middle threaded section to bend. All the others do, so their longevity test can not be known unless purchased with years and mileage placed on them.

If I were to do it, I would still pick up the 034MS ones as I did before. Just seems an all around better design, with rebuild kits for $100/$130 (upgraded kit cost more). But if you want to do this simply for daily driving (not track) and wanting your proper caster/camber back, the inner bushing camber/caster kits would suit the bill just fine. I am not sure how the adjustability is dialed in on them and never really researched it, but should not be that much of a PITA for whoever is doing the alignment.

[agentsmith988]

Well, damn.

They either bend or have catastrophic failure.

What about Moog?

Probably the same as the SPC arms, but you never know. Rock Auto has Moog adjustable control arms but they don't specify the position on the front (I.E., front or rear upper). Does that matter? Is there a difference or are the front uppers basically all the same?

There is a difference. The longer arms in the set go towards the front of the car.

[agart]

Just going to throw out that I have an 034 set for sale with a fresh rebuild kit installed. I ran them for I think 4-5 years and they were great. Rebuild process is very easy and the quality of the parts is excellent. PM me if you're interested!

[Seerlah]

Edit: was doing some research into the SPC arms myself just for shits n giggles, and pulled up this thread: Clicky Click

Something to think about...

In all honesty, I would not even consider the SPC ones after seeing that that thread. Moog is a good brand, but has the same design. That threaded section design also just looks like a problematic area. I have not come across any bad reviews when it comes to the 034 units.

[A4SoftWalker]

Yeah Seerlah my research into the SPC failures turned up that thread as well.
I'm assuming the boot got compromised and the rest followed from there.
All SPC needed to do was sell the dude a half-arm at cost and all that could have been avoided.

IF I go with SPC I would have to increase my scrutiny during regular inspections of the boot. Photos and dates documented.

As fR3ZNO and DarkoNova mentioned it is my guess that SPC since they deal with so many makes of cars might have their design "for sale" perhaps like a franchise chain. Just my guess of course seeing that it is so closely mimicked as to be virtual twins.

[fR3ZNO]

Yeah Seerlah my research into the SPC failures turned up that thread as well.
I'm assuming the boot got compromised and the rest followed from there.
All SPC needed to do was sell the dude a half-arm at cost and all that could have been avoided.

IF I go with SPC I would have to increase my scrutiny during regular inspections of the boot. Photos and dates documented.

As fR3ZNO and DarkoNova mentioned it is my guess that SPC since they deal with so many makes of cars might have their design "for sale" perhaps like a franchise chain. Just my guess of course seeing that it is so closely mimicked as to be virtual twins.

Yeah, I'm not into victim blaming or anything, but I'm sure that ball joint must have exhibited some signs of play beforehand that would have been evident in the steering wheel or wheel and tire if you were to rock it by hand. I can't see how it all of a sudden let go, but you never know.

The SPC and Stern design would be the easiest to adjust, with the turn buckle compared to the 034 design which would require removing the ball joint from the knuckle to thread it in or out.

[A4SoftWalker]

Yeah, I'm not into victim blaming or anything, but I'm sure that ball joint must have exhibited some signs of play beforehand that would have been evident in the steering wheel or wheel and tire if you were to rock it by hand. I can't see how it all of a sudden let go, but you never know.

The SPC and Stern design would be the easiest to adjust, with the turn buckle compared to the 034 design which would require removing the ball joint from the knuckle to thread it in or out.

^^^Undoing that pinch-bolt would be my LEAST favorite go-to option with my car on an alignment rack.

[Seerlah]

It really depends on the tech doing it. And that pinch bolt isn't a problem, unless it has been there for a while and you know it is seized. What I do is take my pinch bolt out and reapply anti-seize on it periodically, mostly when changing my wheels for the seasons. Changed my CAs few months back and they came right out no problem with a simple punch and hammer (little to no effort).

If the bolt isn't seized, pay the money to have the tech do what he does. If it is, I would try and swap that bolt out before bringing your car to the shop for an alignment. Or if you have a reputable shop around you that most know about and work on modified vehicles, just pay the money and have them do the whole install. Some things like this are worth buying the burden away.

[agentsmith988]

Looks like they have a nifty design to make it not quite so bad. And you don't have to touch the pinch bolt.

[Spike00513]

Yeah Seerlah my research into the SPC failures turned up that thread as well.
I'm assuming the boot got compromised and the rest followed from there.
All SPC needed to do was sell the dude a half-arm at cost and all that could have been avoided.

IF I go with SPC I would have to increase my scrutiny during regular inspections of the boot. Photos and dates documented.

As fR3ZNO and DarkoNova mentioned it is my guess that SPC since they deal with so many makes of cars might have their design "for sale" perhaps like a franchise chain. Just my guess of course seeing that it is so closely mimicked as to be virtual twins.

If a tire rotation and oil change is every 5k, I guess that adds control arm boot inspection. I wonder if it's possible to re-boot them with a better quality boot, or to install better quality joints into the arm. Or swap on different outer part halves.
Making your own might not be cheap or easy, and choosing a material different from aluminum might be more damaging in the event of a crash, where aluminum is chosen to be the first point of failure. That way it's strong enough to function as a suspension component, but still weak enough to bend and be replaced by a collision repair facility.
Otherwise, I'm not sure what a different metal part would do, such as iron. If it'd bend the bolt holding it, the holder parts, and tweak the body it's attached to.
Not to mention reducing crumpling effect, and adding weight.

Or what about drilling holes into the other side, to install grease fittings? Even if the boot tears, maybe using a grease gun would push out any contaminating dirt, and re-lubricate any grease that might have escaped from the torn boot.

[Seerlah]

Looks like they have a nifty design to make it not quite so bad. And you don't have to touch the pinch bolt.

Never knew that was how you adjust it. Very simple.

[fR3ZNO]

I guess that video makes the 034 arms adjustment a non issue then, I retract my previous statement. lol. But I would still say the turnbuckle would be easier to adjust on the rack, but if the tech doesn't mind, I'd have more peace of mind with the 034 ones after seeing that SPC thread.

[A4SoftWalker]

I have to agree the 034 arm adjustment is not bad at all with the hex bolt removal for the heim joint end-link.
Still the 034 units are not on my short list. I'm swaying towards the SPC style arms unless I see more failures of the ball joint.
I'm thinking their larger turnbuckle is more resistant to bending than the Stern units.

[Seerlah]

I would conjecture driving style also plays a big role. I would still inquire with SPC if they would sell the ball joint end if the middle threaded section gets compromised. Plus ball joints don't last forever, so that end will need to be replaced eventually. The bushing end you can press a new bushing in when it gets compromised, so that takes care of the inner section.

[fR3ZNO]

Looks like 034 just released a new version of their adjustable arms. Can't really tell any difference between the new ones and the old ones aside from the fillet on the edges instead of a chamfer and the geometry of the pockets on the side. New ones are supposedly "track spec"

edit: new track arms have up to -3 degrees of camber

[A4SoftWalker]

I would conjecture driving style also plays a big role. I would still inquire with SPC if they would sell the ball joint end if the middle threaded section gets compromised. Plus ball joints don't last forever, so that end will need to be replaced eventually. The bushing end you can press a new bushing in when it gets compromised, so that takes care of the inner section.

Good point. I'll get in touch with someone at SPC and report back what I can find.

[old guy]

I have to ask, how low are you? I can tell you from years of experience that you can run a 25" FTG height and and still get very even tire wear.

I wouldn't mess with adjustable control arms unless you want to run something noticeably lower than 25".

[A4SoftWalker]

My ride height is 25+1/8 inch. It might be that I was just out of alignment. Either way the adjustable control arms were on my list of items to install and its the perfect excuse to the better half.
Car was aligned last tire change.
I will post photos of my chewed up tires after approx 25k mi.

[old guy]

My ride height is 25+1/8 inch. It might be that I was just out of alignment. Car was aligned last tire change.
I will post photos of my tires after approx 25k mi.

I don't know if you have seen this Clicky click® I can tell you from my experience that it really does work. I have no problem getting well over 40 miles of even wear on my front tires using these settings.

[DarkoNova]

I saw that thread a while ago and made sure to do that, but I just destroyed my front tires (one blew out, the other, it's a miracle it didn't blow). I believe I'm at 24.5" or 24.75".

I'm already tired of replacing tires so I caved and bought the 034 arms. Although it seems like they're going to be a pain in the ass to adjust, even though their video makes it look quick and easy.

We'll see, I guess.

[V70R]

Looks like 034 just released a new version of their adjustable arms. Can't really tell any difference between the new ones and the old ones aside from the fillet on the edges instead of a chamfer and the geometry of the pockets on the side. New ones are supposedly "track spec"

edit: new track arms have up to -3 degrees of camber

Whoa, that’s quite the adjustment range. Might have to sell my SPC’s for the B5 and go this route.

[old guy]

I saw that thread a while ago and made sure to do that, but I just destroyed my front tires (one blew out, the other, it's a miracle it didn't blow). I believe I'm at 24.5" or 24.75".

So I guess 25" ftg must be about the limit that can be corrected with those settings. Good to know. You did go zero toe-in along with the raised toe adjustment?

Sucks destroying tires:-(

[DarkoNova]

So I guess 25" ftg must be about the limit that can be corrected with those settings. Good to know. You did go zero toe-in along with the raised toe adjustment?

Sucks destroying tires:-(

Honestly I'm not sure. I tried finding my alignment specs but can't find them. I got the car aligned at Firestone but they changed their alignment printouts. I remember it used to be the big red bars with the green section in the middle. Now it's just a bunch of numbers.

Like I think when I got the Nova aligned, it said I had inches and feet for toe instead of the red bar with the green section showing it was good.

I don't like the way they do it anymore. :/

[agentsmith988]

I wasn't a fan of the zero toe setting when I tried it out. The highways here are grooved and the car would wander quite a bit. I'm interested to see what kind of long-term wear I get sitting at -0.8º camber and 0.15º toe on each side. I've also got the raised toe set all the way down.

[old guy]

I wasn't a fan of the zero toe setting when I tried it out. The highways here are grooved and the car would wander quite a bit. I'm interested to see what kind of long-term wear I get sitting at -0.8º camber and 0.15º toe on each side. I've also got the raised toe set all the way down.

You don't have to go all the way to zero to help the tire wear. Factory setting is .08°→.25° so you are pretty much centered to spec. Unfortunately that isn't going to cut it for inner edge wear. I would recommend reducing that by half and it will reduce the wear without introducing any wandering. Reduce by one flat per side and you should go from a total toe of .30° to .15°

[A4SoftWalker]

The first step is to adjust your raised toe setting as far down as your outer tie rods will allow. Simply loosen the 16mm pinch bolt on the outer tie rod, back out the top 13mm adjustment bolt and push the tie rod shaft down as far as it will go. The pinch bolt goes through a groove in the shaft that limits the maximum amount of travel available. Tighten the pinch bolt up and snug the 13mm adjustment bolt. Done.

Basically space the steering ball joint down within the knuckle with the 16mm holding bolt in place and the top 13mm bolt loosened to allow movement?

[old guy]

Loosen the 16mm clamping bolt. Loosen (or remove) the 13mm top bolt. Push the ball joint rod down as far as it will go with the 16mm bolt in place. There is a groove in the tie rod that will limit how far down it can go.

Reclamp the 16mm bolt. Then snug up the 13mm bolt.

Done.

[A4SoftWalker]

Loosen the 16mm clamping bolt. Loosen (or remove) the 13mm top bolt. Push the ball joint rod down as far as it will go with the 16mm bolt in place. There is a groove in the tie rod that will limit how far down it can go.

Reclamp the 16mm bolt. Then snug up the 13mm bolt.

Done.

Thanks for the clarification old guy

- - - Updated - - -

Good point. I'll get in touch with someone at SPC and report back what I can find.

Talked with someone that knew right off the bat about our cars' control arms and he said:

1) Currently if you were to order direct from SPC they have revised the 81350 part to have both a left and right specific part numbers.
2) Some of their distributors might not have got the new part numbers in stock and are selling the older 81350 series part.
3) Warranty claims go through the distributor you purchased from and they contact SPC.
4) Direct out of warranty claims to SPC for the ball joint end of the control arms are $75. They pay shipping one way with the damaged part being sent to them as part of the deal.


Customer service seemed quick and knowledgeable to me. Im getting mine from old stock 81350 series and will post further in my build thread after I complete the install and alignment.

[A4SoftWalker]

Thank You to EVERYONE for your input and for helping me to ask the right questions.
I'm very comfortable going with the SPC brand of ACA (Adjustable Control Arms).

[old guy]

Even if you go with the adjustable upper control arms it would be worthwhile to make the raised toe adjustment. Once you lower the body of the car you change the angle between the steering tie rod arm and steering knuckle. By making the raised toe adjustment you can at least partially compensate for the difference in angle.

[A4SoftWalker]

For sure old guy definitely planning on doing the raised toe adjustment.
Thanks a lot for the heads up.