Steel to Light Alloy Control Arms Conversion

solex3274 · solex3274's Garage

My 1988 924S has the old steel control arms and they are dented and a little beat up. In the 944 workshop manual it does mention that cars with these metal arms can be converted to the later light alloy control arms.

My question is has anyone done this conversion and did you feel it was worth the effort and expense?

ERAU944 · ERAU944's Garage

worth the effort and expense? probably not.

I will be doing the mod soon on my '84 though since I have a spare set of aluminum arms lying around, and the ball joint kit is cheap.

The steel arms are very cheap to replace, and once you have replaced the ball joints in the steel arms once (drill rivets and replace with bolts) it is VERY easy to do again.

There are proponents of both style control arms. Both styles have their good points... I think that in the end this comes down to preference. I do like the looks of the aluminum arms though

billy mild · 05-17-2011, 08:02 AM

The steel arms are only $30 a piece. When I redid the suspension on my 924S I just rebuilt my steel arms. Cost about $40 a side with new bushings included. I would recommend you do that.

ERAU944 · ERAU944's Garage

well, a brand new arm itself is $40, isn't it? it's been a little while since i checked.

then, add another $20 for the ball joint and you are at $60 per side.

then add another few dollars for the bushing and you are at roughly $70 per side for brand new a-arms for the early setup.

IMO that's about the cheapest replacement of a major piece you can get on a P-car

that same $140 will go most of the way towards a track quality ball joint kit for an aluminum arm that you will never have to replace or rebuild again (so long as you don't go off-roading and/or the bushings don't get destroyed by power steering fluid).

I've done both style ball joints, and I far prefer rebuilding the newer style. For the price, you can't beat the steel ones. The only catch comes in sourcing yourself some good rebuildable late style control arms.

whalebird · 05-17-2011, 09:24 AM

Only the 86 (early offset) arms will work on a 924S. Alloy that is.

Rasta Monsta · Rasta Monsta's Garage

The steelies freshen up pretty well. . .

YES, I know the rear bush is backwards. . .flipped it before installing!

Capt Squid · 05-17-2011, 09:44 PM

The 944 Spec racers that have had aluminum ball joint failures on their 85 1/2 cars almost all switch to the steel arms. Put them both on a scale, I think there is no weight advantage to the aluminum arms. While not a hard job, it is a slight PITA to replace the ball joints on the aluminum arms. With hard use, they do wear out.

AA_Ezra · 05-17-2011, 11:16 PM

All you need is a Vice, Fridge, some wd-40, crc silicone spray and a little soapy water or rubing alchohal or beter yet some Ru-glide from Napa used to install rubber components like tires and a Large socket to help install the rear bushing.

solex3274 · solex3274's Garage

Thanks for the advice, I will simply rebuild my steel A arms.

moorepower · 05-18-2011, 05:31 PM

The red bushings in Rasta's pic are Prothane brand for a Mk1 VW. These are better quality than Weltmeister poly bushings, and at about $25 for a full set, you can't beat 'em.

I just put new steel A-arms, ball joints, and Prothane bushings on my 924S for a total of just under $100. The alignment afterward costs more than the parts, fer cryin' out loud.

Rasta Monsta · Rasta Monsta's Garage

FWIW, I also had mine seam welded. . .cheap insurance against those spot welds letting go.

v2rocket_aka944 · 05-18-2011, 06:54 PM

NFW i would blow $600 a side on aluminum arms when superior steel ones are $23 or $3 off a VW at the boneyard...btw, cast aluminum can shear...

John_AZ · 05-19-2011, 05:21 AM

Rasta,

Did you put in Zert fittings?

John

Rasta Monsta · Rasta Monsta's Garage

John, I did not. I used marine outboard grease, so far no squeeky after 4 years.

MJinCO · 05-21-2011, 05:18 AM

I'm working on modifying a steel A arm for the late model sway bar using late model drop links so I got an old Aluminum arm. On my not precise scale, the aluminum arm with ball joint and no bushings was just at 5 lbs, the steel arm with ball joint and bushings weighed 6lb 4 oz. The aluminum looks really neat and feels light, but that is a lot of money for 2.5 lbs of unsprung weight. Finding lighter tires next time around would get a much greater unsprung weight reduction. Just my opinion.

billy mild · 05-21-2011, 04:15 PM

I have an 86 944 Turbo what would I have to do to run Steel Arms.

v2rocket_aka944 · 05-23-2011, 09:26 AM

Quote:

Originally Posted by MJinCO

I'm working on modifying a steel A arm for the late model sway bar using late model drop links so I got an old Aluminum arm. On my not precise scale, the aluminum arm with ball joint and no bushings was just at 5 lbs, the steel arm with ball joint and bushings weighed 6lb 4 oz. The aluminum looks really neat and feels light, but that is a lot of money for 2.5 lbs of unsprung weight. Finding lighter tires next time around would get a much greater unsprung weight reduction. Just my opinion.

you can get the bigger later bars to work with the early mounts, i have a 25.5 turbo bar in my NA using the factory sway mounts. did have to do some 'persuasion' on the outer bushings though. no problems in 4 years though.