Knocking on steering on new GLC

[Druk]

Followed this thread with interest and kudos to Grober for spotting the possible cause.

My worry if I were an owner would be for the medium to long term prospects of the transmission components. It's all very well for Merc to say 'it's supposed to do that' but it doesn't do it on LHD models and I'm sure they will share the same driveline components as their RHD sisters. So presuming these components were stressed by Merc's engineering design team, I'm betting the extra overload placed on various components by this constant snatching won't have been allowed for in the original design brief. What's the snatching going to be like once things start to loosen off a bit and there's play in the various gears?
Three years down the line when driveshafts and input seals and bearings start to fail is it going to be "Sorry Sir but that's out of warranty" and a bill for several thousand quid for repair? And what when the cars get to (say) six or seven years old?

Good luck with that

Edit. Anyone posted this vid? Must be doing the suspension balljoints a world of good.

https://www.youtube.com/watch?v=VTT0U8fciR0



.

 

[dejongj]

I have no doubt it's related to this, which was my first thought when I first saw the thread. Anyone who has driven the old type of manual locking centre differentials (ie the original early Range Rovers) with them locked on a hard surface will have experienced the juddering /clunking as the wheels try to 'spin' momentarily to release the 'tension' in the system; unless it breaks first.

Modern systems are more complex and some are electronically controlled, but the same laws of 'physics' apply.

It might be typical of the parameters built into the system, much like a GT-R transmission 'grumbles' and shunts in low speed manoeuvring. Whether a GLC should be like that is a different question.

I don't see that 7 degrees C is a magical figure.

Has anybody with an affected car tried driving it on, for example, wet slippery grass and, if so, does the car still exhibit the same tendencies?

Yes, I agree and that was my first interpretation as well. And I can confirm it doesn't do it on wet grass, nor on the snow/ice we had last week. Exactly how I expected it to behave. It was very good once you don't give it a non-slip surface.

 

[dejongj]

Followed this thread with interest and kudos to Grober for spotting the possible cause.

My worry if I were an owner would be for the medium to long term prospects of the transmission components. It's all very well for Merc to say 'it's supposed to do that' but it doesn't do it on LHD models and I'm sure they will share the same driveline components as their RHD sisters. So presuming these components were stressed by Merc's engineering design team, I'm betting the extra overload placed on various components by this constant snatching won't have been allowed for in the original design brief. What's the snatching going to be like once things start to loosen off a bit and there's play in the various gears?
Three years down the line when driveshafts and input seals and bearings start to fail is it going to be "Sorry Sir but that's out of warranty" and a bill for several thousand quid for repair? And what when the cars get to (say) six or seven years old?

Good luck with that

Edit. Anyone posted this vid? Must be doing the suspension balljoints a world of good.

https://www.youtube.com/watch?v=VTT0U8fciR0



.

Not me but I know who it is My camera angle was different in my slow mo movie but I will redo it from other angles and noted the same.

 

[hallra]

Hi,

I've had an accident this morning, travelling at a very low speed into the close where I live.

(A single lane one way road goes down towards the right and the opens up upwards to the left, then through an archway into the area where my house is.)

As I've come down the hill, turned slightly to the left and gone up, (covering the brakes), the front tyres have instantly lost grip, the car stopped turning and travelled straight on.

I've tried to turn the steering, i've tried applying the brakes firmer, I've instinctly tried several ways to get out of the slide, nothing happened, the car proceeded to slide into a brick wall.
- It felt just like the full lock slip/judder problem, not a normal skid, wasn't traveling fast enough, the front wheel grip just went away from me...


The antilocking brakes haven't kicked in, actually none of the safety systems have kicked in.

The front left of the car is severelydamanged. It's the left, not the right thats damaged because the car literally has not turned at all.

I might add, that everyone of my neighbours that has driven into the close has not experienced any tyre slipping today, though it is a little slippery out there, there is no ice, the road is made from block pathing with gaps between the brickwork for rain and extra grip.



Has anyone else experienced anything like this? It was just like the problem with the judder/slipping at full lock, the front wheels have just lost grip and control of the car has been lost.

 

[grober]

While sympathetic to your plight I feel we are in danger here of possibly confusing two issues. The main problem manifests itself as wheels juddering at walking pace at extreme steering lock. I cannot equate " walking pace" with "severe damage " so assume your car must have been travelling at higher speed/ less lock . In your particular case what you may have experienced is front understeer exacerbated by the rear wheels tending to drive a 4WD car in a forward direction despite the front wheels attempting to turn. This is an unfortunate characteristic of 4wd cars in general and can catch out inexperienced owners unfamiliar with this handling characteristic. It's possible of course there was some sort of fault with the car that caused the accident but I get the sense its not the particular one discussed in this thread.

 

[hallra]

While sympathetic to your plight I feel we are in danger here of possibly confusing two issues. The main problem manifests itself as wheels juddering at walking pace at extreme steering lock. I cannot equate " walking pace" with "severe damage " so assume your car must have been travelling at higher speed/ less lock . In your particular case what you may have experienced is front understeer exacerbated by the rear wheels tending to drive a 4WD car in a forward direction despite the front wheels attempting to turn. This is an unfortunate characteristic of 4wd cars in general and can catch out inexperienced owners unfamiliar with this handling characteristic. It's possible of course there was some sort of fault with the car that caused the accident but I get the sense its not the particular one discussed in this thread.

Hi Grober,

I am aware of what front understeer is, I don't believe it was this and having driven for 30 years, passed advanced driving and taken track driving courses, I think I'm not an inexperienced driver.

The exact same slippage that occurred today during the accident has also occured during judder/slip/grip on full lock problem.

the car was travelling at walking pace, the road layout doesn't allow you to travel at any speed and I was also travelling slower than normal because I had my pet cat it the car after taking him to the vets...

Unfortunately hitting a brick wall even at a snails pace does serious damage...





Sent from my SM-T805 using Tapatalk

 

[dejongj]

Hi,

I've had an accident this morning, travelling at a very low speed into the close where I live.

(A single lane one way road goes down towards the right and the opens up upwards to the left, then through an archway into the area where my house is.)

As I've come down the hill, turned slightly to the left and gone up, (covering the brakes), the front tyres have instantly lost grip, the car stopped turning and travelled straight on.

I've tried to turn the steering, i've tried applying the brakes firmer, I've instinctly tried several ways to get out of the slide, nothing happened, the car proceeded to slide into a brick wall.
- It felt just like the full lock slip/judder problem, not a normal skid, wasn't traveling fast enough, the front wheel grip just went away from me...


The antilocking brakes haven't kicked in, actually none of the safety systems have kicked in.

The front left of the car is severelydamanged. It's the left, not the right thats damaged because the car literally has not turned at all.

I might add, that everyone of my neighbours that has driven into the close has not experienced any tyre slipping today, though it is a little slippery out there, there is no ice, the road is made from block pathing with gaps between the brickwork for rain and extra grip.



Has anyone else experienced anything like this? It was just like the problem with the judder/slipping at full lock, the front wheels have just lost grip and control of the car has been lost.

Wow - very sorry to hear that. Have you got any pictures to share with us? I'd also be interested to see picture of your left front wheel/tyre especially. I wonder what wear pattern you have.

 

[hallra]

Pics

Pics 1

 

[hallra]

Pics

Pics 2

 

[hallra]

Tyres

4555 - Front Left
4556 - Front Right


Car has done 6k

 

[hallra]

Accident

My insurance company are now pushing Mercedes for answers, if it is a mechanical fault, Mercedes are liable.
- Mercedes have taken away the car for inspection.

On reflection, the accident is quite bizzare:

- How did I lose control of the car at such low speed?
- Why didn't the car turn and/or stop, even though the car was moving slowly for some distance whilst the brakes were being applied, uphill?
- Why didn't any of the emergency systems, anti locking brakes, etc kick in?
- How did a 4x4 will all the latest gadgetry lose grip?

 

[CaptainChaos]

My insurance company are now pushing Mercedes for answers, if it is a mechanical fault, Mercedes are liable.
- Mercedes have taken away the car for inspection.

On reflection, the accident is quite bizzare:

- How did I lose control of the car at such low speed?
- Why didn't the car turn and/or stop, even though the car was moving slowly for some distance whilst the brakes were being applied, uphill?
- Why didn't any of the emergency systems, anti locking brakes, etc kick in?
- How did a 4x4 will all the latest gadgetry lose grip?

Sorry to hear about the mishap.

Was there black ice on the surface? It's been very cold these last few mornings and your description has all the makings of a low speed skid on ice. I once managed a similar trick into my gatepost.

Bear in mind that four wheel drive only helps get you moving. It does not aid you slowing down or cornering. That's entirely down to your tyres. Are they runflats out of interest?

 

[hallra]

Sorry to hear about the mishap.

Was there black ice on the surface? It's been very cold these last few mornings and your description has all the makings of a low speed skid on ice. I once managed a similar trick into my gatepost.

Bear in mind that four wheel drive only helps get you moving. It does not aid you slowing down or cornering. That's entirely down to your tyres. Are they runflats out of interest?

Hi Captain,

I checked the ground afterwards, I would say the ground was a little slippery but there was no ice. The accident occured around midday, the outside tempreture was around 8/9c

They are the original tyres on the 20" AMG Alloys, I believe they are run flats.

 

[dejongj]

Hi Captain,

I checked the ground afterwards, I would say the ground was a little slippery but there was no ice. The accident occured around midday, the outside tempreture was around 8/9c

They are the original tyres on the 20" AMG Alloys, I believe they are run flats.

If your car is recent then I doubt they are run flats. I understand that bar the original supplied cars Mercedes stopped doing those for UK GLC's.

 

[hallra]

If your car is recent then I doubt they are run flats. I understand that bar the original supplied cars Mercedes stopped doing those for UK GLC's.

Car registered Mar 2016, spec says:

R01 Summer Tyres
R66 Run Flat Tyres

The car was an Ex Demo with 50 miles on clock


Sent from my SM-T805 using Tapatalk

 

[dejongj]

Car registered Mar 2016, spec says:

R01 Summer Tyres
R66 Run Flat Tyres

The car was an Ex Demo with 50 miles on clock


Sent from my SM-T805 using Tapatalk

Yes, they were still doing run flats then

 

[hallra]

Yes, they were still doing run flats then

A friend of mine suggested that maybe when the car first lost grip, the electronics put power to the wheels to get out of the slide and this is why the car didn't slow down and continued into the wall...
- I want to post some more pics that show how tight it is entering the area where the accident occurred, to show everyone how slow I would have been going when at the bottom of the hill. Having problem with an attachment size limit of 1.2Mb

Got at email from the garage service manager, apparently car has been inspected and he will call me tomorrow once he has had the feedback from his foreman. I don't hold my breath as I wouldn't expect Mercedes to put their hands up...





Sent from my SM-T805 using Tapatalk

 

[hallra]

Additional Pics

Pics showing how tight it is, entring the area where I hit the wall.

 

[dejongj]

Is it me, but to me that doesn't show or demonstrate how tight it is. Am I missing something?

 

[CabrioDave]

It's probably difficult to get the photos to show how it really is. To me, the first photo certainly looks like a country lane bend that you could do at 45 ...