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Mercedes GLC Clonking and juddering on near full steering lock

Mines a 250d sport on the standard issue 18" wheels/tyres. Bought Nov 2015, not run flats.

Mines does it both forward and reverse, the colder the temperature the less steering input is required to get the bumping/clonking. when 4-5 degrees, the effect happens on about 1/2 lock at slow speeds. When it's really warm, it's almost not there at all.

Question, if this is happening on 1/2 lock on slow speeds (and for others on less lock in some circumstances), what is the logic/mechanics that says it is not happening at higher speeds. Is it possible that it's happening, but because it is happening a lot quicker, it's not felt as distinct bumps, but that it is still there, and having an effect on stability/ road holding ?

The question I'm asking is why does this only happen at slow speed, one imagines the various forces acting on the tyres are much greater at higher speeds ?
 
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Mines a 250d sport on the standard issue 18" wheels/tyres. Bought Nov 2015, not run flats.

Mines does it both forward and reverse, the colder the temperature the less steering input is required to get the bumping/clonking. when 4-5 degrees, the effect happens on about 1/2 lock at slow speeds. When it's really warm, it's almost not there at all.

Question, if this is happening on 1/2 lock on slow speeds (and for others on less lock in some circumstances), what is the logic/mechanics that says it is not happening at higher speeds. Is it possible that it's happening, but because it is happening a lot quicker, it's not felt as distinct bumps, but that it is still there, and having an effect on stability/ road holding ?

The question I'm asking is why does this only happen at slow speed, one imagines the various forces acting on the tyres are much greater at higher speeds ?

How many miles have you covered and what's your tyre wear been like?
 
A couple of threads on these US forums which may be of interest?
https://mbworld.org/forums/e-class-...sfer-case-bearing-noise-new-transmission.html
New Transfer Case at 10,000 miles? - Mercedes-Benz Forum

US Models potentially affected

2012-2013 C300 Luxury 4Matic
2012-2013 C300 Sport 4Matic
2011 CL550
2013 CL550
2012-2013 CLS550
2012-2013 CLS550 4Matic
2011-2013 E350
2011-2013 E350 4Matic
2011-2013 E350 BlueTEC
2011-2013 E550
2011-2013 E550 4Matic
2013 GLK250
2010-2013 GLK350
2010-2013 GLK350 4Matic
2012-2013 S350
2011 S550
2011 S550 4Matic

https://mbworld.org/forums/attachme...-transfer-case-bad-li28.00-p-051499_ver_4.pdf

The problems appear to arise from bad engineering tolerances in the 4MATIC drive train with several owners getting their transfer boxes replaced. This might also explain why some owners experience little or no problem and some do. So there is no "one size fits all " solution to this type of problem.
Now this may or may not effect RHD 4matic cars but for MB to claim that this is some sort of "model characteristic" is perhaps a bit disengenuous bearing in mind their US experience of similar 4WD drivetrain complaints. It's perhaps a sad indictment of our litigious society that manufacturers are now increasingly constrained from being more forthcoming about such problems. :dk:
 
I understand why you posted the above Grober but I'd strongly suspect it may only confuse the issue. Simply, I don't think one should use them as comparable unless the 4Matic systems are the exact same as currently fitted to GLC's and C43's. Also, one has to take into account all of the above are L/H/D and older models centred around mainly E and S-Classes which would bring it's own uniqueness.

As a current day example the 4Matic system in the C43 is not the same as used in new E63 according to Car magazine. Now, I'll be the first to admit that may not add up to a hill of beans but what it could imply is that even over a short period of time there may have been several variations of 4Matic depending on model.

I really think it would have been a blessing for GLC R/H/D owners if the L/H/D versions had the exact same fault.
 
I appreciate what you are saying. The mechanical assemblies altho related may be different. The point I was making was that some of the symptoms seemed similar and appear to be related to the phenomenon known as transmission windup??
 
What does the difference between RHD and LHD in planetary gears mean? I lack the understanding as to whether that makes an impact?
 
I appreciate what you are saying. The mechanical assemblies altho related may be different. The point I was making was that some of the symptoms seemed similar and appear to be related to the phenomenon known as transmission windup??

I don't honestly know. I'm just not knowledgeable enough to debate that. Modern four wheel drive systems seem rather sophisticated and that would include the M-B 4Matic system. So, the old and common 4X4 transmission windup of a very basic system I would guess shouldn't come into play here? Of course that doesn't mean that windup is not occurring.

Admittedly, I always suspected it was a drivetrain issue and probably the front diff (lack of slip) being the culprit after viewing one of the GLC videos but whether it's caused by electronic control or just mechanical I haven't a clue if that is the problem.

The most telling aspect is that it seems confined to R/H/D versions which have a different torque bias front to rear than L/H/D model from what I recall - don't quote me on that but I may read it on this forum. And even just as telling is excessive front tyre wear that's been reported. A tyre expert would hazard a good guess by just viewing the these tyres aggressive wear pattern as to the likely basic cause of this issue.
 
I don't honestly know. I'm just not knowledgeable enough to debate that. Modern four wheel drive systems seem rather sophisticated and that would include the M-B 4Matic system. So, the old and common 4X4 transmission windup of a very basic system I would guess shouldn't come into play here? Of course that doesn't mean that windup is not occurring.

Admittedly, I always suspected it was a drivetrain issue and probably the front diff (lack of slip) being the culprit after viewing one of the GLC videos but whether it's caused by electronic control or just mechanical I haven't a clue if that is the problem.

The most telling aspect is that it seems confined to R/H/D versions which have a different torque bias front to rear than L/H/D model from what I recall - don't quote me on that but I may read it on this forum. And even just as telling is excessive front tyre wear that's been reported. A tyre expert would hazard a good guess by just viewing the these tyres aggressive wear pattern as to the likely basic cause of this issue.

My web research seems to suggest:-

1. the RHD 4-Matic system is significantly different from the LHD variant.

2. there are no electronics involved in the torque split within the transfer box, it relies upon pre-set mechanical 'clutch-slip'.

To me, the fact that the LHD/RHD systems differs at all (other than being opposite hand) and the effect/fault is only unacceptable on RHD variants, supports any theory that blames the transfer box.
 
I don't honestly know. I'm just not knowledgeable enough to debate that. Modern four wheel drive systems seem rather sophisticated and that would include the M-B 4Matic system. So, the old and common 4X4 transmission windup of a very basic system I would guess shouldn't come into play here? Of course that doesn't mean that windup is not occurring.

Admittedly, I always suspected it was a drivetrain issue and probably the front diff (lack of slip) being the culprit after viewing one of the GLC videos but whether it's caused by electronic control or just mechanical I haven't a clue if that is the problem.

The most telling aspect is that it seems confined to R/H/D versions which have a different torque bias front to rear than L/H/D model from what I recall - don't quote me on that but I may read it on this forum. And even just as telling is excessive front tyre wear that's been reported. A tyre expert would hazard a good guess by just viewing the these tyres aggressive wear pattern as to the likely basic cause of this issue.

I always hesitate before posting information that may or may not be relevant to the issue at hand especially in a climate where hard engineering information is thin on the ground. But working on the principle that forums are about communication I usually try post it in a non judgemental fashion and let folks draw their own conclusions. :dk:
 
The question I'm asking is why does this only happen at slow speed, one imagines the various forces acting on the tyres are much greater at higher speeds ?

I think you'll find that at very low speed the outer wheel slows or completely stops rotating - at higher speed the rotation will be sufficient for the tyre to more easily shed tension that builds up between the contact surface and rim.
 
Dryce said:
I think you'll find that at very low speed the outer wheel slows or completely stops rotating - at higher speed the rotation will be sufficient for the tyre to more easily shed tension that builds up between the contact surface and rim.

..and full lock at high speed in reverse or any other gear is unlikely. So it may well happen but would go undetected due to lack of use.

Sent from my iPhone using MBClub UK
 
I still haven't go my car back after dropping it in for a geometry check last Wednesday. First it was the replacement tyres that couldn't be here until Friday. Then the geometry chap wasn't around to redo the checks. The. I got a cryptic encouraging message on Friday from my dealer group contact. And now I've noticed a post on honest John that is starting to make some sense of it.

I think Mercedes UK will soon be releasing an update on this whole situation confirmed what us fuss makers have been saying all along ;) Next week could be interesting.
 
I still haven't go my car back after dropping it in for a geometry check last Wednesday. First it was the replacement tyres that couldn't be here until Friday. Then the geometry chap wasn't around to redo the checks. The. I got a cryptic encouraging message on Friday from my dealer group contact. And now I've noticed a post on honest John that is starting to make some sense of it.

I think Mercedes UK will soon be releasing an update on this whole situation confirmed what us fuss makers have been saying all along ;) Next week could be interesting.

Yes the HJ article refers to MB offering Winter tyres for free but owners can wait until next winter to claim/use. Yes next week will really be interesting!! Don't suppose that will help the uneven wear on summer tyre usage though!!

This is the actual GLC owner's post a couple of hours ago on the HJ site:

''Hi chaps
dealers have been notified that Merc admit it is a difference between the steering geomerty on the left hand drive cars as opposed to the right hand ones.

Right hand car owners will be offered free change to all weather tyres for cars with 18,19,20" wheels.

As yet no fix for 21" wheels cause they cant source all weather 21" tyres.

Dont need to accept the offer now, can save it till winter this year...so use your current tyres now and get a free set in winter.''


May ask my dealer to agree to a set of summer tyres when mine wear down instead of winter tyres as not a major problem for me and see what they say!! LOL. Also noticed is says ALL WEATHER TYRES not specifically WINTER TYRES not sure whether they could be used all year round?
 
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Yes the HJ article refers to MB offering Winter tyres for free but owners can wait until next winter to claim/use. Yes next week will really be interesting!! Don't suppose that will help the uneven wear on summer tyre usage though!!

This is the actual GLC owner's post a couple of hours ago on the HJ site:

''Hi chaps
dealers have been notified that Merc admit it is a difference between the steering geomerty on the left hand drive cars as opposed to the right hand ones.

Right hand car owners will be offered free change to all weather tyres for cars with 18,19,20" wheels.

As yet no fix for 21" wheels cause they cant source all weather 21" tyres.

Dont need to accept the offer now, can save it till winter this year...so use your current tyres now and get a free set in winter.''


May ask my dealer to agree to a set of summer tyres when mine wear down instead of winter tyres as not a major problem for me and see what they say!! LOL. Also noticed is says ALL WEATHER TYRES not specifically WINTER TYRES not sure whether they could be used all year round?
I think it'll be a wait and see as we have had these reports previously of things moving forward I.E the Feb 17th announcement and then nothing happens. Fingers crossed.

Whether a change of tyres would make a difference I guess we will find out soon enough, from what some others have said, a tyre change won't solve it.

Interestingly, the garage I bought my GLC from had offered to take the car away to do their own independent tests and they also offered to exchange it with another GLC, but then have gone silent this week, it might/might not be linked to the impending announcement.
 
I think it'll be a wait and see as we have had these reports previously of things moving forward I.E the Feb 17th announcement and then nothing happens. Fingers crossed.

Whether a change of tyres would make a difference I guess we will find out soon enough, from what some others have said, a tyre change won't solve it.

Interestingly, the garage I bought my GLC from had offered to take the car away to do their own independent tests and they also offered to exchange it with another GLC, but then have gone silent this week, it might/might not be linked to the impending announcement.

Yep but after all is said and done should MB offer this to owners assume it will only be those with the current GLC/C Class 4Matic? also not convinced that those with significant cluncking may not still be doing some kind of damage to the mechanical elements of their car even though winter tyres are fitted.
 
Yes, Alfie owns a business that actually fits audio/etc equipment to more than just Mercedes.

If you had fully read *any* one of his posts properly you will have read his signature which says: -

Comand (Europe) Ltd: We're listed on MBClub please click to see services and discounts available.


Just like my posts have a sig. about Comand Online. Actually as most people on the forums don't differentiate Comand (europe) and Comand Online, you can also see that I work with Alfie from the previous posts etc you have looked at. So no pretending anything there.

Now, just to add more clarity. I am the one that owns the GLC that Alfie refers to. (as per my profile), its a GLC250d , Model Year 2017 with the standard wheels. In cold weather, at low speed when reversing I get the odd clunk. I ignore it because so many of the other customer cars i've driven do the same on full lock. The ML63 I had before did not do this though.

The GLC has done about 8k miles now and there is no sign of tyre damage / excess wear. In fact, I haven't even complained to Mercedes about it. (and some may remember the issues I had with the COMAND system when I bought it, so it did go back to Mercedes for issues I was concerned about.

I'm just waiting to see what Mercedes say now.

My personal guess is that the minimal noise i get is "normal" and because it 4WD, cold, for the reasons described early in this (or similar) threads. However, I suspect there is another issue that makes it worse on some cars, perhaps an alignment issue from factory or something on certain models or wheel sizes. I also suspect that those cases are not being well dealt with because of all the other people who have been worried by the odd clunk having seen these long threads in forums. I.e these threads doing some owners a dis-service because its made people who would not have noticed/been-bothered complain which means *all* complaints get answered with the current company response of "not dangerous, need winter tyres" rather than the dealer technicians actually investigating the problem on a much smaller subset of vehicles.

BUT, whereas I understand the electronic systems in cars well, I do no mechanical work at all - I ask others to do that !!

Cheers

Richard

Without trying to reignite this, I've avoided replying to this till now as I wanted it to calm down a little.

Being personally attacked on this forum is not what I'm here for, i'm here to discuss issues I have experienced with my GLC and I'm looking to discuss this with others that have similar issues, I'm not here to be told i'm an idiot, a fool, i'm mistaken, i'm having a medical episode or anything similar.

* Note an accounts posting signatures is not visable when accessing this forum via TapTalk, plus Business and personal posts on the same forum account is something that should be frowned upon, because not mater what the attention is, it can be misleading and across many industries, this sort of thing is against the law, I know because I work in the finance industry and many people have end up in jail.

I had a go at Alfie because he was attacking another user on this forum and he had very strong personal opinions on what is all the fuss about, as he has said in his opinion, nothing unique here, he has seen it on many many cars and it's normal. However, Alfie works in the motor industry and is also according to his account an MB enthusiast, and as such, people who work in a particular industry and/or an enthusiast in something will always have a different views and different tolerance levels to that of a lay person. So you have to be mindful of what you say and how you say it. As an example, I work in the IT industry, I see lots of people struggle with their home computers, they see things totally diferent to me as an expert, even though I don't specialse in Home computers I am far more informed than they are, so I know and I understand my views and what I may consider nonesense, is not the way they will see it, so I refrain from attacking them and belittling them.


As we know many people have experienced this issue, it's across many forums, websites, newspaper articles, Mercedes half admit it's a problem.

We know the problem is intermittent, we know the problem affects some more than others, we know people have different tolerence levels, we know some people don't see an issue.

Some people are talking here about this issue as it is affecting them in some form, they have gone to Mercedes and feel they haven't got the resolution they seek. These people are exchanging experiences and discussing the differing stories that Mercedes have told. They are here to support each other and look for support from others. They are not here to be attacked, insulted, belittled, told they have nothing to worry about, etc.

I hope eveyone can pull together and support each other, that's all i'm looking for.

Oh, apart from the dig at me, nice thought out post Richard!
 
Yep but after all is said and done should MB offer this to owners assume it will only be those with the current GLC/C Class 4Matic? also not convinced that those with significant cluncking may not still be doing some kind of damage to the mechanical elements of their car even though winter tyres are fitted.

Yes, agree with you. I still haven't been convinced that something within the setup of my car hasn't been effected to such an extent that it had a material effect on the accident I had. I am talking to various entities to get expert opinion.

(Note this is my own speculation.)
 
I was going to buy one but after trying a discovery sport I think I'll try tha. No issues with any amount of lock/steering angle.
 
Well well well it seems us kicking up a fuss wasn't so foolish after all. I wonder whether those saying it is normal will put their claim in now as well.

Still loads of questions to be answered around the details, but at least Mercedes has admitted there is an issue and that it isn't normal.

Soon we find out who are men and who are boys ;)
 

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