Rusted Control Arms

[colinallcars]

Decided to set about replacing the springs and dampers on the SLK but opened a can of worms instead. In addition to every nut and bolt requiring to be cut owing to rust, the lower, rear control arms are disintegrating. New ones are on order from Autodoc which will take about a week to arrive plus some nuts and bolts from eBay. The damage was not visible (passed its MoT last month) as they have a plastic cover which unfortunately collects mud, salt and water.

 

[DSM10000]

Just as well you found it now!

 

[amazighman]

They usually have covers on the protect them , Mercedes and rust have a love affair

 

[OneForTheRoad]

They usually have covers on the protect them , Mercedes and rust have a love affair

He mentions the covers as the reason behind the rust.

 

[amazighman]

He mentions the covers as the reason behind the rust.

Owned a fair few rusty mercs and the control arms were in good shape , even on w210

 

[ray_hennig]

Gosh and I thought 107s and 123s were rust buckets!!!

R

 

[W1ghty]

Decided to set about replacing the springs and dampers on the SLK but opened a can of worms instead. In addition to every nut and bolt requiring to be cut owing to rust, the lower, rear control arms are disintegrating. New ones are on order from Autodoc which will take about a week to arrive plus some nuts and bolts from eBay. The damage was not visible (passed its MoT last month) as they have a plastic cover which unfortunately collects mud, salt and water.

View attachment 132674
View attachment 132675
View attachment 132676

How much are the new ones buddy ? I’m about to remove mine on the rear of the CLk to change the shocks , springs and drop links .

 

[colinallcars]

How much are the new ones buddy ? I’m about to remove mine on the rear of the CLk to change the shocks , springs and drop links .

Got them from the Autodoc app for just under £75 each, they only have Vaico in stock. Going to give them a couple of coats of Hammerite before I fit them. You’re likely to butcher the large nuts on the bolts that retain the arms, one is M12x1.5 and the other is M14x1.5. I’ve ordered them from eBay. Hopefully you’ll be able to save the bolts like I did.
FINE PITCH NYLOC NUTS NYLON INSERT LOCK ZINC PLATED M10 M12 M14 M16 M18 M20 M24 | eBay

 

[W1ghty]

Got them from the Autodoc app for just under £75 each, they only have Vaico in stock. Going to give them a couple of coats of Hammerite before I fit them. You’re likely to butcher the large nuts on the bolts that retain the arms, one is M12x1.5 and the other is M14x1.5. I’ve ordered them from eBay. Hopefully you’ll be able to save the bolts like I did.
FINE PITCH NYLOC NUTS NYLON INSERT LOCK ZINC PLATED M10 M12 M14 M16 M18 M20 M24 | eBay

Thanks for that , I’m trying to pluck up the motivation to do it on the drive . Had a quick look yesterday to find the damper top nuts in the boot underneath all the convertible roof gubbins , so you could say I’ve started already

 

[colinallcars]

Gosh and I thought 107s and 123s were rust buckets!!!

R

The effect of 21 Scottish winters! The car looks not too bad otherwise although I did replace the front wings a number of years ago and it needed a front spring perch a couple of years back, both owing to rust.

 

[noogieman]

Lemforders manufactured in the wrong country are like shite!
I bought them parts and they rusted like cr@p after 3 months during summer, EuroCarParts selling crap!
Buying these parts should have stamp made in Germany, not Italy or China!

 

[ray_hennig]

Buying these parts should have stamp made in Germany, not Italy or China!

Back in 2016, I sunk 1000€ in 2 lower control arms for my W124. Both genuine MB, made by TRW. One from Germany, one from Slovakia.

R

 

[grober]

Mercedes-Benz SLK-Class (R170) - Wikipedia

en.wikipedia.org

your car stems from the days of the ill-fated Chrysler Mercedes alliance. Several models from that era suffered from major corrosion problems--- this was due to the use of poor quality steel-- rumoured to be of Russian/Eastern block origin

 

[colinallcars]

Mercedes-Benz SLK-Class (R170) - Wikipedia

en.wikipedia.org

your car stems from the days of the ill-fated Chrysler Mercedes alliance. Several models from that era suffered from major corrosion problems--- this was due to the use of poor quality steel-- rumoured to be of Russian/Eastern block origin

Indeed. I think I’ve actually got one of the better ones given it is still on the road. If I can get another two years out of it I’ll be delighted.

 

[noogieman]

Back in 2016, I sunk 1000€ in 2 lower control arms for my W124. Both genuine MB, made by TRW. One from Germany, one from Slovakia.

R

I think genuine control arms purchased from MB could be powder coated for added protection?
But I could be wrong?
Aftermarket control arms only have a thin coat of paint which doesn't last very long on salty roads.
Water based paint can't keep rust away.

 

[colinallcars]

I think genuine control arms purchased from MB could be powder coated for added protection?
But I could be wrong?
Aftermarket control arms only have a thin coat of paint which doesn't last very long on salty roads.
Water based paint can't keep rust away.

I’ve noticed a modification in the picture of the replacement arms. They have a drain hole at the bottom of the spring seat which is the lowest point.

 

[Petrol Pete]

Giving them a quick sand down and clean before spraying the new ones is a good call , also drill a few drain holes in the plastic covers.

 

[colinallcars]

Old meets new

 

[merc85]

I did shocks and springs on the back my Clk, I left the plastic covers off the arms.

 

[colinallcars]

I did shocks and springs on the back my Clk, I left the plastic covers off the arms.

I’ve been thinking of doing that.