Downgrading lower control arms (R129/W124)

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dj_coleman

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Aug 1, 2008
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hi all - quick question. I have ordered new lower wishbone bushes and new balljoints for my R129 1998 SL500. ... only to find out I have the later lower control arms with non-changeable ball joints. I believe it is the same suspension as the W124?

So the question is - is it possible to fit the earlier control arms with changeable ball joints? I understand that the later ones are probably an improvement but as time goes on they will become even rarer and more costly than now. I do not have EDS or anything on my car. I read some places that brakes may need more clearance but that also seems connected to EDS-equipped cars?
Thanks
 
I believe it is the same suspension as the W124?
I think so too. My 124 is a 24 valve Sportline and that means it has bigger brake discs. The upshot of which is that you need the non-removable ball joint arms to clear the bigger discs.

I'm hoping that the new 500€ arms will last 25+ years like the originals. If so, cost justified. If not ....

Sadly, no alternatives are now available and the best price I've found for mine is now 530€ at my usual supplier: Suche nach OE - Original-Ersatzteil-Nummer

So, for you, it seems that you need to dig deep. But it is a 500SL so I have no sympathy!

All the best.

RayH
 
Hi Ray - thanks - so you think that it is not possible to downgrade to older style arms due to the brakes sizes? Maybe I should downgrade the brakes as well ... :)
My lower arms are OK at the moment so I will probably replace the boot that is looking a bit dodgy and hope for the best for now.
It is because I have an SL500 that I need to save money :)
 
you think that it is not possible to downgrade to older style arms due to the brakes sizes? Maybe I should downgrade the brakes as well ..
Hmmm!

I really can't imagine downgrading the brakes.

What are the part numbers for your lower control arms? Does this ring a bell: 1243303007?

This is not the same part number as mine and there appear to be more options.

Your first step is to find the correct MB numbers and start Googling. I got results at AutoDoc.

And at Teile Profis a 1243303007 ONLY costs 380€.

Good hunting.

R
 
If price is a consideration, Febi do cast ball joint arms for about a quarter of the price of genuine. I sincerely doubt the genuine ones will last 4 times as long.
 
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Hi Ray - thanks - so you think that it is not possible to downgrade to older style arms due to the brakes sizes? Maybe I should downgrade the brakes as well ... :)
My lower arms are OK at the moment so I will probably replace the boot that is looking a bit dodgy and hope for the best for now.
It is because I have an SL500 that I need to save money :)
If you alter the braking system away from standard then your insurance company may decline cover.
 
Thanks for all comments - for now I am going to replace the rubber boots only. Lets see if it fails next MOT...
 

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