Mercedes GLC Clonking and juddering on near full steering lock

[grober]

It may be usefull to differentiate here between SSR Tyres [self supporting runflat tyre] and the ones using Contiseal technology which may not have the heavy re-enforced stiffened sidewalls. That said both types advise a TPM [tyre pressure monitoring] system??
I can only assume CONTISEAL tyres may have a more suitable elastomer / sidewall for some reason?
Continental Tyre Technology - Extended Mobility Solutions

 

[dejongj]

Interesting. So the way to notice a puncture is by a loss in tyre pressure? But it won't go really flat? So you then need the compressor to increase the pressure.

 

[dejongj]

Key question to me; am I being reasonable to demand to have the same type of tyre all round?

 

[Smerck]

When I had my x3 a couple of years ago I got an x-drive malfunction indication after changing 1 tyre due to a puncture. BMW diagnosed that the other 3 were worn down sufficiently (still over 2mm but I can't remember what) to cause a difference in rolling circumference so advised all 4 to be changed to rectify. Lease company eventually relented and changed the other 3, problem went away.

 

[grober]

Again we are cursed with the loose use of terminalogy. The original Contiseal tyres as fitted to the VW CC Coupe are "self sealing tyres" with the sealant built in. This is a slightly different tech than the more common Contiseal tyre repair kits which involve normal tyres with sealant+ inflation compressor. These are designed to re-inflate punctured tyres from flat as opposed the self sealing tyre where they should not go flat in the first place. --at least that's how I understand it.
Continental Tyre Technology - Extended Mobility Solutions

 

[kid-jensen]

The LAST THING you need in a tyre is extra weight, especially ~50% extra.

Weight is the enemy of everything you want a car to do, accelerate, turn, stop, ride the bumps....you get the picture.

The fact that that are run-flats makes them even worse.

I'm not in the OPs end of the market, but I wouldn't have a runflat tyre of any kind on my car, and certainly not just one pair!

Tell them to put the recommended replacement tyres on there, and if ALL the recommended tyres are runflats (which I'm sure they aren't) tell them they can have their car back....

 

[Steveml63]

Hi,
I have closely studied the various YouTube videos that show the tyre popping on full lock with the affected GLCs.
OMG - I would be thoroughly peed off if this happened on my car!
The steering geometry is all wrong on these cars.
On full lock the inside wheel pulls the car round and the outer wheel (which has further to travel) is effectively being pulled sideways - causing the tyre sidewalls to "pop" as the tyres continue to grip the surface.
This is quite shocking and certainly not good for either the tyres, steering or suspension components.
This is definitely a fault and certainly not an acceptable "characteristic"
MB engineers have a bit of work to properly fix this problem - replacement tyres is certainly not a fix, merely a time stalling bodge job.
Cheers
Steve

 

[dejongj]

Again we are cursed with the loose use of terminalogy. The original Contiseal tyres as fitted to the VW CC Coupe are "self sealing tyres" with the sealant built in. This is a slightly different tech than the more common Contiseal tyre repair kits which involve normal tyres with sealant+ inflation compressor. These are designed to re-inflate punctured tyres from flat as opposed the self sealing tyre where they should not go flat in the first place. --at least that's how I understand it.
Continental Tyre Technology - Extended Mobility Solutions

So how do you know you have a puncture and it will require replacing?

 

[dejongj]

The LAST THING you need in a tyre is extra weight, especially ~50% extra.

Weight is the enemy of everything you want a car to do, accelerate, turn, stop, ride the bumps....you get the picture.

The fact that that are run-flats makes them even worse.

I'm not in the OPs end of the market, but I wouldn't have a runflat tyre of any kind on my car, and certainly not just one pair!

Tell them to put the recommended replacement tyres on there, and if ALL the recommended tyres are runflats (which I'm sure they aren't) tell them they can have their car back....

I wonder whether the tyres are truly heavier as they are ContiSeal and not Run Flat. My apologies as I didn't appreciate that they are different.

 

[dejongj]

Does anyone know where you can find out the weight of a tyre? I've looked at the manufacturers website and camskill and the likes but can't seem to find anything?

 

[Deleted member 37751]

Oh wow that is a lot heavier.

There may be some exaggeration on my part and the difference may be less than 50% but when you physically feel the difference you'd be amazed.

 

[dejongj]

This is getting silly now, my dealer seems to refuse to also swap the rear tyres to the same type. I really don't get this. Mercedes is offering replacement all season tyres for everyone but they can't for the 21" owners. Yet my dealer is only willing to change the front tyres to a different type for me but not the rear. Yet they are willing to supply an extra set of 20" wheels with all season tyres. Surely it would be more cost effective to only swap the tyres?

I'm totally confused now.

 

[grober]

How much does a tyre weigh? » Oponeo.co.uk
would indicate a normal tyre would weigh in around 10-15 Kg depending on size [ tread is the heavy bit]
e.g. a 205/55R16 weighs in at 9.5 Kg [ measured] Contiseal would add about 1-2 Kg. Can't speak for the runflat SSR but 50% would take it up to 15+7.5= 22.5 Kg = slightly less than a bag of cement you might find in Wickes.

According GM's technical people SSR tyres weigh in at anything between 20 and 40 % heavier presumably depending on load rating?
http://www.autosafety.org/air-runs-out-run-flat-tires/

 

[190]

The LAST THING you need in a tyre is extra weight, especially ~50% extra.

Weight is the enemy of everything you want a car to do, accelerate, turn, stop, ride the bumps....you get the picture....

This is so true. There is a double whammy effect of the overall weight of the vehicle going up and on top of that, the rotational inertia of the wheel going up which impacts on all the things mentioned above.

It may not be a huge impact overall but in principle wheels are the worst possible place to add weight to a vehicle and the very best place to reduce weight.

 

[DRIVER200]

This is getting silly now, my dealer seems to refuse to also swap the rear tyres to the same type. I really don't get this. Mercedes is offering replacement all season tyres for everyone but they can't for the 21" owners. Yet my dealer is only willing to change the front tyres to a different type for me but not the rear. Yet they are willing to supply an extra set of 20" wheels with all season tyres. Surely it would be more cost effective to only swap the tyres?

I'm totally confused now.

I would now go for the 4 x 20'' wheels/tyres and see how you get on. Then come the warmer months get your dealer to change them back to your original 21's. They may then think twice about this!!

 

[bluelights22]

I rang my MB stealer yeaterday and informed them of the problem, they said that this was a comfort issue and nothing else. I gave them a few choice words from my naval vocabulary, basically saying that this is a cop out and it's wont work with me, I will take them to court under the sales of goods act. The problem was known by MB before I purchased my car in August 2016. If I'd have been told that this would happen, I would not have bought a defective car.
They said there is a fix, a set of all weather tyres installed for free, after they have inspected the car to make sure there is no other problem.
I asked them if the new tyres would fix the problem? the service department was vague, I asked if the tyres were run flat? and that I wont be accepting run flats! They didn't Know that either.
I asked why have I paid £45k for a top of the range motor when I could have got a run of the mill one from another maker, he couldn't answer that either!

 

[Steveml63]

Hi,
The predecessor to the GLC was the GLK.
Interestingly that car was never engineered for RHD.
If you look on Wikipedia it gives the following reason for this:-

The GLK-Class is not sold in RHD markets, such as the United Kingdom and Australia, due to a driveshaft used to operate the front wheels on 4WD versions of the GLK. It is positioned such that it encroaches slightly on the right-hand-side footwell. In August 2014, however, it was announced the GLK-Class will be sold in the United Kingdom from Q4 2015.

Interesting!
Cheers
Steve

 

[Deleted128943]

My GLC 250d AMG Line Coupe has 19" run flats fitted and during a recent 200 mile journey mostly on motorways I averaged just under 47 mpg which seemed pretty good for such a heavy vehicle. I suspect the harder tyre walls improve rolling resistance which counteracts the affect of additional weight....

 

[DRIVER200]

I would now go for the 4 x 20'' wheels/tyres and see how you get on. Then come the warmer months get your dealer to change them back to your original 21's. They may then think twice about this!!

dejongj: Any news on your situ?

 

[swale]

any glc owners found that the clonking isnt as bad as weather is warmer?