Rollover bar deployed on 2005 CLK

[Nawest]

Drove the car this morning and almost straight away got a strange sound from the rear, it was almost like the clicking you hear when car panels are cooling down after driving on a hot day, but much deeper and louder and with an echo (whatever it was was in an enclosed but empty void). Every small bump I drove over was accompanied by the same 'click' until one bump caused an almighty bang from the back as the roll bar engaged and the hazard lights came on.

Tried resetting the roll bar by pressing the button on the dash, but after research it appears that button is just to lower the rear headrests when they've been raised manually. I then discovered how to insert an Allen key/screwdriver down the side of each headrest to release a spring and push the headrests back down. I tried this as indicated but couldn't locate the spring mechanism, let alone try and get my arm between the headrest and the roof to try and exert enough pressure to try and force the headrest down (apparently it takes a great deal of weight).

I then rang our local dealer who said the car would need hooking up to diagnostics to be reset and would cost nearly £100.

Has anybody else had experience of this? The resetting doesn't overly worry me but the preceding sounds make me think something broke, which sounds expensive!

 

[grober]

These systems have limit switches on the rear suspension arms to trigger the roll bars in the event of a car roll over. Sounds a bit like one of them has come loose or you might have a broken rear spring. Without getting the car up on a ramp its going to be difficult to check it out properly.

 

[AndyPCD]

Quite a common problem with the roll over bar.

If the dealer wants to put it on a diagnostic machine they are ripping you off as the roll over bar is mechanical and cannot be reset by the diagnostic machine.

Its quite fiddly to reset and has to be done a lot by feel but once you have done a few its quite easy.

What area are you in. We might be able to recommend an indy to take it to to get it sorted.

 

[Nawest]

Thanks for your help. The spring breaking might be a possibility, I've heard creaking from the rear for a little while. My father's E class was creaking for a while before his spring broke, so that might be it. How would I know just by looking if the spring had gone?

I'm in Doncaster, South Yorkshire.

 

[Nawest]

Just had a look and compared both rear wheel wells and there's definitely something protruding into one of them from above, and that something looks distinctly like the edge of a spring. So I'm guessing that's it. I've just read that springs should be replaced in pairs, is that correct?

 

[grober]

Just had a look and compared both rear wheel wells and there's definitely something protruding into one of them from above, and that something looks distinctly like the edge of a spring. So I'm guessing that's it. I've just read that springs should be replaced in pairs, is that correct?

Absolutely correct- apart from keeping the handling "even" if one has broken- usually thro stress corrosion - chances are the other one is probably on the way out also. Make sure you get the correct rated springs from MB. That roll over assembly frame is quite heavy and the car will possibly require a slightly higher rated spring from the normal CLK coupe

 

[Nawest]

Thanks for that. Final question: should I drive the car or not? Obviously I'd have to take it easy, but is it advisable to drive ten miles to the garage or does it need collecting? The part that is protruding is well clear of the wheel and brakes.

 

[W4E300]

I had exactly the same issue recently and took the opportunity to put a set of lowering springs and dampers on my 500, which transforms the handling and has got rid of the 'roll' it used to suffer from. Strongly recommend it......

Sent from my iPad using MBClub UK

 

[grober]

Thanks for that. Final question: should I drive the car or not? Obviously I'd have to take it easy, but is it advisable to drive ten miles to the garage or does it need collecting? The part that is protruding is well clear of the wheel and brakes.

The answer to that is don't know. People drive around with broken springs all the time but don't know it.Usually that's because they break at the ends rather than the middle- sounds like your one broke in the middle- worst case scenario is the spring is displaced sideways and destroys your tyre sidewall /collapsing the suspension. Only you can decide- I certainly wouldn't be driving anywhere very fast!

 

[jaymanek]

If you looks through the gap between the headrest and seat you will see the hole in which he Allen key must be inserted. The stitches on the headrest are a guide. Then you push the Allen whilst simultaneously using all of your weight to push down on the headrest...

 

[Nawest]

All sorted. Drove to garage. New springs fitted £210. Used a tent peg (my car didn't come with an Allen key) to depress the headrest spring and pushed down the headrests. Much smoother ride at the back end now.