Suspension Arms???

Howey

Howey

Member
England
Got ball joint cover issues again on the cast/forged arms a year on since battling with the j+r jobbies!!

Got me thinking should a ball joint develop wear then i will be looking at a new arm and therefore bush assembly

Looking on ebay the bargain cast/forged arms are much more cost effective for petrol engines (what the difference is i do not know, do you?)

Therefore, for a TDI i could only really find cost sensitive parts on euros sister carparts4less. Dare i say it using pressed arms (starline??) And then injecting/treating with anti-corrsion can then get Lemforder bushes and ball joints at very good money i think with the lot for both sides currently coming in at £115, these would then make future ball joint changes a breeze and cost effective, plus folks who have switched from pressed to cast/forged have reported increased road noise so another win for pressed!! Keep on top of any corrosion and i am feeling pressed is the way to go?? Any thoughts??
 
I agree, cast arms are great but not user friendly when it comes to ball joints. The pressed arms Audi fitted can last a long time BUT many do fail due to corrosion. Touch wood my pressed ones are still going strong 17 years later. So with a little TLC and regular checking I think pressed arms are still a very viable option. Why there is such a price difference between petrol and diesel cast arms I do not know, even if the diesel ones have a larger cross section.
 
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audifan said:
I agree, cast arms are great but not user friendly when it comes to ball joints. The pressed arms Audi fitted can last a long time BUT many do fail due to corrosion. Touch wood my pressed ones are still going strong 17 years later. So with a little TLC and regular checking I think pressed arms are still a very viable option. Why there is such a price difference between petrol and diesel cast arms I do not know, even if the diesel ones have a larger cross section.
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I would reckon it's due to the weight of the diesel donkey .. main dealer subaru wanted $600 for a left hand bottom arm and $800 for the right hand side and when I asked why they said it mainly because of the amount of right hand bottom arms that get smashed up .. ( the aussies are not known for their ability to drive ???) so the main dealer was cashing in...
 
Personnally i would prefer the cp4l starline arm with lemforder ball joint bought to fit for less than that but happy to hear of any other pressed tdi arms as quite frankly i am struggling!!
 
Unfortunately under the current global regime, parts supply is not great. All items must be sold fit for purpose. So whatever brand you can find available unless you have a good reason not to buy them then I would say go for it. Nowadays I tend to think most items are disposible and not built to last for ever. Saying that if you have good drop links and a new pressed arm, I would consider replacing the arm at the same time as either the ball joint failing or the drop links wearing, that way corrosion should not be much of an issue even if you do not add additional rust proofing to the arm.
 
I replaced pressed for cast but having said that the OEM pressed lasted 13/14 years. I think it depends on how much you drive in the winter and how much salt is put down by your highways dept. Also, if you regularly wash the underside with a spray jet that must help. And spraying them inside with a preservative must be a good idea.

The reason I think many go for cast is that corrosion on the inside is difficult to spot. I recall there was one case where the A2 passed its MOT and a few weeks later the suspension arm collapsed! Not good if you are doing 80mph down the motorway. Maybe an endoscope* could be used once per year to check or simply inject more preservative every year or so.

* I bought one on ebay fairly cheaply that works with a smartphone.
 
Does anyone know the weight difference between the cast and pressed versions? Must be quite considerable I would have thought?
 
re. "The reason I think many go for cast is that corrosion on the inside is difficult to spot. I recall there was one case where the A2 passed its MOT and a few weeks later the suspension arm collapsed! Not good if you are doing 80mph down the motorway."

Concern about failure of an arm at high speed is understandable - just wondering if anyone has heard of a failure occurring under such circumstances? In my youth it was not unusual to see a Morris Minor with the front wheel & hub assembly tucked under the wing due to a failure in the front suspension. My understanding was that this only seemed to occur when manoeuvering for parking - the loading can be high under these circumstances.
Mark
 
Perhaps it is the cars fault. No do not shoot me let me try to explain a little. The A2 is renown for its aluminium and other non ferrous construction, so much so that people forget there are steel components fitted to each car and these do deteriorate with time. Pretty sure most owners are only under the car perhaps once a year and that is doing service items. They are shocked to find disc backing plates disintegrating but even then do not thoroughly check any other steel component tucked away out of sight. So when the car gets its annual MOT the inspector pushes and prods what he is allowed to but even then may not notice something corroded from the inside.
So all I suggest is if you have cast wishbones fitted then please check the other steel components carefully and if you have pressed arms do the same and pay a bit more attention to their internal condition.
As far as the replacing of the arms is concerned. I think both types of arms have their own problems. Cast will need to be replaced if the ball joint is worn, pressed the greater corrosion but the ability to replace just the ball joint. Personally the pressed ones have been on my car 17 years and will more than likely I will replace them with more pressed steel ones when I need to.
 
audifan said:
Perhaps it is the cars fault. No do not shoot me let me try to explain a little. The A2 is renown for its aluminium and other non ferrous construction, so much so that people forget there are steel components fitted to each car and these do deteriorate with time. Pretty sure most owners are only under the car perhaps once a year and that is doing service items. They are shocked to find disc backing plates disintegrating but even then do not thoroughly check any other steel component tucked away out of sight. So when the car gets its annual MOT the inspector pushes and prods what he is allowed to but even then may not notice something corroded from the inside.
So all I suggest is if you have cast wishbones fitted then please check the other steel components carefully and if you have pressed arms do the same and pay a bit more attention to their internal condition.
As far as the replacing of the arms is concerned. I think both types of arms have their own problems. Cast will need to be replaced if the ball joint is worn, pressed the greater corrosion but the ability to replace just the ball joint. Personally the pressed ones have been on my car 17 years and will more than likely I will replace them with more pressed steel ones when I need to.
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Couldn't agree more.

Personally having owned cars with both varieties I wouldn't swap out pressed for cast but as you say would replace them with new pressed if and when required.

Ours are 17 1/2 years old and still fine so I wouldn't consider them problematic or a design fault either as I'm sure Audi replaced the earlier cast one's with the pressed one's for a reason, or maybe several of them.....weight, noise and ability to replace the ball joint being three off the top of my head?
 
A2Z said:
Couldn't agree more.

Personally having owned cars with both varieties I wouldn't swap out pressed for cast but as you say would replace them with new pressed if and when required.

Ours are 17 1/2 years old and still fine so I wouldn't consider them problematic or a design fault either as I'm sure Audi replaced the earlier cast one's with the pressed one's for a reason, or maybe several of them.....weight, noise and ability to replace the ball joint being three off the top of my head
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Cost is the primary one. On the a4 platform of the same era (mk4 golf, Leon, tt, a3) the pressed arms were on the lower models and cast was reserved for the TT and s3


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Edwrai said:
Cost is the primary one. On the a4 platform of the same era (mk4 golf, Leon, tt, a3) the pressed arms were on the lower models and cast was reserved for the TT and s3


Sent from my iPhone using Tapatalk
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The manufacture cost of both would be very cheap so I can't imagine that would be Audi's reason for fitting one or the other, maybe strength could be a factor?
 
A2Z said:
The manufacture cost of both would be very cheap so I can't imagine that would be Audi's reason for fitting one or the other, maybe strength could be a factor?
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Pressed sheet steel parts are cheaper the manufacture than cast parts.


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I suspect that when Audi designed the A2 the ordered a batch of cast arms at a set price. When that batch ran out I assume the cost had dramatically increased so Audi went to a different supplier for cheaper pressed ones. Perhaps they got a good deal as other vehicles from the group were having pressed arms at the same time.
 
I would really like to know the actual reason but I still don't believe the difference in cost between these relatively 'low cost' items was Audi's reason for changing but I could be wrong?

I believe it would have been a more technical reason ?
 
I have a pair of new QH cast arms available if needed. They owe me about £75.00. Available at cost, not needed as A2 Delinquent already has healthy cast arms.
 
audifan said:
I suspect that when Audi designed the A2 the ordered a batch of cast arms at a set price. When that batch ran out I assume the cost had dramatically increased so Audi went to a different supplier for cheaper pressed ones. Perhaps they got a good deal as other vehicles from the group were having pressed arms at the same time.
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Are the 'cast' arms steel or an aluminium alloy?
 
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