S203: Rear Springs

[davemercedes]

A noise that occurred very slightly when cornering or going over raised ridges etc just turned out to be a rear coil spring (again!). It's been replaced and of course the noise has gone and I'm happy that I won't suddenly find half my exhaust coming apart when "moving" on the motorway etc But - and it's a big but: how come this is the third or maybe fourth spring I've had to replace in five years? It really annoys me that the car handles fine right the way through the spring breakage with the only clue when it's there being a light tinkling/graunch. I think it was last year, that the car failed the MOT because of one broken spring and at the time I'd had no noises occur so I had no idea of the problem.

I'm really surprised - that the engineering standard in this area seems to let me down - the car now has 99.6K on the clock but generally still feels and drives "like new" with no rattles or shakes etc but with all the cars (and that's many brands, both new and pre-owned), that I've had over nearly 60 years I've never had to replace a rear spring before this car!

I understand the Estate rear suspension layout design is somewhat "naff" in that the springs sit directly metal-to-metal in a mounting "cup" and it's been this end that has broken off each time. So I just wondered, has anyone ever done what would seem to my mind to be a fairly simple mode and introduced a nylon seating or anything or shall I just save up some of my pocket money to pay for the next one?

 

[davemercedes]

Funny (no, it isn't) but I've had a rear spring changed once again today - it was exactly the same as the last four (or is it five I've coughed up for?) i.e.: it started when an intermittent noise could be heard when if I went over a ridge or small pothole. I'm very lucky to have a superb local garage and when I phoned about it, as usual they had me pop over to check on Thursday and then did the job today.

As previously the noise sounds like an exhaust "clonk" but in reality it's the end of the spring wallowing about and re-seating itself in the metal "cup" that it sits in.

At least when the noise starts I know now that I can drive with care until I get it sorted but it still surprises me because I hardly have any non-maintenance tasks on my car from one year to the next!

 

[grahamcol]

I never had a spring break until owned a Merc. One of my 202's plus my newly purchased 209 each had a broken rear spring on delivery (and with brand new MOT). Whilst driving the 209 all the way home l could hear the occasional clank and l knew instantly what the cause was. Seems very common but l don't necessarily think it's confined to Mercs.

 

[Oldspanners]

Odd indeed that you have so many break I know the C class doesn't feel happy on rough surfaces. According to the service history on my car it had a front break about 10 years ago and both were replaced. I checked the rears properly after buying and all I could see was they were very rusty as the coating was flaking off. I wire brushed the remaining off and gave them a good coating of rust inhibitor and primer not that that's a preventive measure but at least I can see any cracks.
The roads here are in the main smooth and pot hole free so that may help.
I haven't noticed any mods for the spring seating but it sounds like a good idea.

 

[Wighty]

Maybe worth trying a different make of spring next time ?

 

[Uncle Benz]

Clean the cup area in the bottom arm thoroughly - remove all grit and debris. Check the drain holes are clear in the bottom, and grease the lower third of the spring to try to combat the rust. Its usually grit that works its way through the protective coating and then the rust gets them