Living with steering vagueness

[Flying Scot]

Thanks philharve & Flying Scot

Take my hands off of the wheel?

Did I not mention the inconvenience of steering correction whilst using the phone, reading a map and lighting a cigarette (all at the same time) - and as for driving with your knees...

I am attempting to not be overly critical - my 'other car' is a 1995 Mitsubishi Evo III and therefore at completely the other end of the steering vagueness spectrum i.e. there isn't any

However, I did attempt a 'slight release of grip' (Flying Scot) on the wheel in the interest of seeing whether it was an abvious issue with tracking - the car did not attempt to veer off course; further investigation revealed that the veicle was responding to track condition (well, M4 surface around Bristol) - this became even more noticeable traversing some favourite B-roads where I was concentrating like mad to keep the car between the verges at some rather modest speeds...not the most pleasant nor enjoyable sensation and as I mentioned previously, not what I expected from a M-B.

However, I feel my expectations are realistic - if I wanted to be frightened, I'd blindfold myself and then try the motorway trip, but in the wrong direction and on the opposite carriageway...!!

I was just wondering if anyone has approached M-B UK with these concerns?

There may be a perfectly reasonable explanation that collectively hasn't been found by forum members but is known to M-B e.g. worn track rod ends - do we know if the car has a propencity for 'munching' any particular parts...

Just a thought...

Julian

cant really decide what to make of this post is it serious tongue in cheek or just flippant and after reading the post on the 'other place' i can only suggest that crosswind stability on the Severn bridge is down to lots of things including the cars aerodynamic profile sheesh even your F1 car is seriously affected by wind conditions - However i thought this thread was about the cars basic straight line instability or more correctly its inherent lack of any. That said If you drive a M Evo III i wonder if you are not expecting a lot (too much) from your MB I regularly drive a MK2 Toyota MR2 a Lancia Delta Integralle and a Volvo 850 Est and a Fiat Punto as well as the SL500 they all respond quite differently for obvious reasons. I dont expect the SL to corner like the MR2 or the Integralle and i know i can relax when in the SL and let the car follow the road with minimum input from me - in the Integralle or the MR2 if i sneeze i will be off the road

just a thought or two

 

[COUPE FREAK]

now ,of course they(bmw and merc) use very lightweight rack and pinnion on all their models because of "road feel" i have not read all of this post ,but it does seem unusuall to have vague steering on r&p

not all mb's are r&p,, my 1993 220ce is steering box and drag link,, not sure what is fitted to the newer models, but i think up to at least 2000 mb's are'nt r&p,,

 

[philharve]

Hi All

I was rather hoping that this thread would receive a contribution from an owner of something like a WRX or Evo and I haven't been dissappointed. I've never driven either of these rally-bred, road racers but I instinctively knew their handling must be second to none. An MB, by comparison, is quite a different animal and probably more at home on motorways or autobahns than bendy A and B roads. I'm not surprised to learn that these cars can run rings around most MBs.

In response to an earlier comment about letting go the steering wheel ... I can do this now and the car will happily track in a straight line down a straight road. But I wouldn't dare think about doing this with slightly harder tyres because they make the car feel like straight ahead isn't an option without considerable driver effort.

PIT - pilot induced turbulence! Before I started experimenting with tyre pressures I went through a phase were I was filled with self doubt. I thought the twitchiness was an inherent characteristic of the C-class and/or recirculating ball steering in general. I even thought that buying a Mercedes was a mistake and maybe I should have purchased a BMW instead. To make matters worse almost every hire car I drove on business seemed to exhibit a similar problem but not to the same extent. Were all these experiences a manifestation of PIT? Was I the real problem? I was beginning to think so.

After carefully reviewing the problem I realised the handling issue wasn't always present in every car I drove and therefore there must be a real underlying mechanical cause rather than a psychological one. However, the handling issue made me slightly nervous/suspicious of every hire car I drive

Through a process of elimination I have been able to track down the C-class handling problem, at least in my particular case, to a sensitivity in tyre pressures. I still think worn dampers is partly tp blame but it is not severe enough to warrant replacement at this time.

I, too, have experienced the crosswinds along the Severn Bridge but I cannot decide whether it's worse along the old or new bridge. Crossing either demands close attention to steering if crossing quickly. It must be much worse for high-sided vehicles. I can only recall one occasion when the old bridge was closed due to a toppled lorry.

REGARDS Phil

 

[Suckmyrockets]

cant really decide what to make of this post is it serious tongue in cheek or just flippant ...

Any flippancy was only in the earlier suggestion of taking hands off the steering wheel to see if the vehicle wandered. If you care to read the rest of the thread in context then you will see this.

I have driven many different vehicles from motorbikes to HGV, fwd, rwd & 4wd. And that's just the road-going stuff. All have different handling characteristics and idiosyncrasies.

The point I am making is that I have never owned or driven a vehicle so affected as my C220D and I don't appear to be alone judging by the evidence on this , and other forums.

I can assure you that my expectations are realistic and I take each vehicle I drive on merit. What I wasn't expecting were such 'interesting' characteristics displayed by my car...joining this thread was pursuant to addressing this issue.

Any constructive comment with a view to resolution would be gratefully received.

 

[Flying Scot]

Any flippancy was only in the earlier suggestion of taking hands off the steering wheel to see if the vehicle wandered. If you care to read the rest of the thread in context then you will see this.

well actually that was what kunfoosed me - however i was 100% serious re taking your hands off the wheel - no need to actually take them away from the wheel but just stop holding onto it

I have driven many different vehicles from motorbikes to HGV, fwd, rwd & 4wd. And that's just the road-going stuff. All have different handling characteristics and idiosyncrasies.

me too and just thinking about bikes i have ridden a Honda ST1100 and a Ducatti Senna prob equate to the MB and the EVO though the ST100 was rock steady.

The point I am making is that I have never owned or driven a vehicle so affected as my C220D and I don't appear to be alone judging by the evidence on this , and other forums.

I can assure you that my expectations are realistic and I take each vehicle I drive on merit. What I wasn't expecting were such 'interesting' characteristics displayed by my car...joining this thread was pursuant to addressing this issue.

Any constructive comment with a view to resolution would be gratefully received.

well here unless you have a physical technical problem with something broken or not functioning issues like this are down to peoples perceptions and fixes are total conjecture - so i guess you need to get some sort of 'expert' owner to drive it to discover if the car has a problem - and if it is a standard problem - in that this model is a bit 'interesting' to drive - something i seriously doubt - or if you have a 'technical problem with this car'

Constructively all i can suggest is that you get some real time help - find at least three - ideally more drivers of this model - and members of this list - who are fairly local to you - and go drive each others cars - with a decent sample - you should be able to discover where the problem lies - with your expectations - this particular model of MB - or your individual car - anything else especially here is total conjecture.

Helpful or not i really dont know but i truly cant see any other option unless you want to go through the suspension, steering, wheels and tyres replacing each and every component and really that cant be done in a piecemeal way it would need to be done all at once - and then of course you would have no idea if it was just one component or the complete overhaul of the running gear that fixed (assuming it did) the problem.

 

[television]

I promissed to send phil a report in the trade press on shock obsorbers, while in the proccess my PC went down, and they did not go.
It was when Phil said that it was better when he reduced the presure in the tyres that started me thinking. The higher the pressure the more they will bounce over the road surface. It would appear that shocks may well work OK in genral, but after some miles they loose the ability to deal with higher frequency movement, so that if the wheels are bouncing slightly the shocks cant iron it out, under the worst conditions the car could take up a different possition in the road, hence the instablity.
I think it was Clive Williams who said that he was veiwing another car in germany and looking out of the window he could see the other car's suspension working hard.
The article in the trade press concluded that there are no ways to test for this, the only thing to do is to drive along side the other vechile and watch the suspension.

Malcolm

 

[Flying Scot]

It was when Phil said that it was better when he reduced the presure in the tyres that started me thinking. The higher the pressure the more they will bounce over the road surface. It would appear that shocks may well work OK in genral, but after some miles they loose the ability to deal with higher frequency movement, so that if the wheels are bouncing slightly the shocks cant iron it out, under the worst conditions the car could take up a different possition in the road, hence the instablity.

Malcolm

I see that (reduction in pressure making things more acceptable) as the disconnection between the tread and the wheel - if you reduce the pressure you are taking away a lot of the side wall stability so in effect you are introducing a delay between your steering wheel input and the reaction at the tread on the road - a sort of steering damper that will iron out steering wheel input - which sort of leads me - or led me to suggest PIT - then of course you have some serious downsides - the increase in the running temperature in the tyre - and the increased wear due to the tyre running hot - as well as the non uniform wear on the tyre - with outside edges of the tread wearing most as well. In addition by altering the rolling radius you are altering the steering geometry - which could in fact be dumbing down the steering response

This of course could indeed be a tyre issue and that the make and model of the tyres fitted to these vehicles are 'unsuitable' for this particular model of MB. We are assuming of course that these cars are running on the correct sized tyres :evil:

But as i said previously - this is a feel issue - not a hard and fast technical problem with 'hopefully' a known fix - so the responses are all conjecture and opinions - and worth about as much as you have paid for them :roll:

 

[clive williams]

Hi all,

In my experience all car suspensions begin to deteriorate as soon as they leave the showroom but one area that most people ignore or are unaware of is the bushing. Having rebuilt several car suspensions for road and competition my first port of call for any kind of replacement is the bushes. Usually the change is astounding! I bet even the EVO and STI boys would be surprised at the transformation.
Car manufacturers usually use rubber in the bushes to isolate the road vibrations from the cab and allow a measure of compliance (or IMO floppyness) in the suspension. These bushes are hard worked and may indeed have to distort to follow the natural suspension movement. Also, particularly on the front they may have to contend with hot dirty oil, which is their death knell.
Therefore, complaints of vagueness may be the result of the wheels not being under full control - its like trying to control a bike by pushing it with a rubber hose! You will probably find that the vehicle will revert to being perfectly sharp and controlable with all the floppyness taken out of the suspension.

Clive

500E
E320CDIT210

 

[COUPE FREAK]

But as i said previously - this is a feel issue - not a hard and fast technical problem with 'hopefully' a known fix - so the responses are all conjecture and opinions - and worth about as much as you have paid for them :roll:

it's not a "feel issue",, go on any mb site and you'll find lot's of question's about vague steering, with various model's,

not sure if it's a design fault with some models of mb, or they've just put too many rubber bushes etc on them to make them feel smooth, and if the bushes etc are'nt in tip-top condition it makes it wander,, just my 2p worth,, (this opinion is free)

 

[Flying Scot]

it's not a "feel issue",, go on any mb site and you'll find lot's of question's about vague steering, with various model's,

not sure if it's a design fault with some models of mb, or they've just put too many rubber bushes etc on them to make them feel smooth, and if the bushes etc are'nt in tip-top condition it makes it wander,, just my 2p worth,, (this opinion is free)

Of course it is a 'feel issue' i am lucky enough to drive one of the 'performance' MB's which at 2 tons and 155K miles on the clock drives and handles like a dream - my 'normal' car is a Volvo 850 Est 190K miles has uprated suspension wheels and tyres and also handles like a dream - having driven quite a few MB vehicles over the years i was never overly impressed by the handling of any of the cars i drove - love their Actros and Atego trucks though - but not the cars - the cars felt a bit like my old 400K miles rolly polly Volvo 740TI which was ****** fast in a straight line but was not very sharp in the handling stakes and was interesting round the twisty bits and decidedly not much fun drivng fast unless i was feeling really brave or mad - if you are expecting a MB saloon to feel sharp i would say your going to be very disappointed - If you are the sort of person that likes sharp handing cars i would say your not going to be happy with a MB saloon - i suspect jumping from any performance car like a BMW Scooby or Mitz EVO you are going to wonder who designed the MB range of saloons - but then really they were not designed with you in mind - of course YMMV
__________________

 

[Suckmyrockets]

... If you are the sort of person that likes sharp handing cars i would say your not going to be happy with a MB saloon - i suspect jumping from any performance car like a BMW Scooby or Mitz EVO you are going to wonder who designed the MB range of saloons - but then really they were not designed with you in mind - of course YMMV
__________________

I thought these (MercedesBenz Saloon cars) were designed in Germany for the Autobahn and associated speed de-restriction (well, it would have been greater in 1995 when my car was manufactured...)

I'm not expecting a 1995 C-Class with a recorded 130K to 'handle' like a brand new 'sports saloon' (like the BMW M3?), but nor did I expect it to 'handle' like the Exxon Valdez...

[N.B. by the use of 'handle' I am referring specifically for the excessive requirement (IMHO) for steering correction at relatively modest speeds c.70 m.p.h., a tendency for the vehicle to be strongly affected by cross-winds, and what has been described by other forum contributors as a 'vagueness' to the steering or a tendency to 'wander']

An interesting viewpoint to suggest that Herr. Marshmallow who had overall responsibility for steering and suspension for the C-Class development at Mercedes Benz was pampering to one specific group of customers or potential customers. Who did they have in mind precisely?

What aspersions are being cast over the users of this, and other MB-related forums?

 

[clive williams]

I thought these (MercedesBenz Saloon cars) were designed in Germany for the Autobahn and associated speed de-restriction (well, it would have been greater in 1995 when my car was manufactured...)

I'm not expecting a 1995 C-Class with a recorded 130K to 'handle' like a brand new 'sports saloon' (like the BMW M3?), but nor did I expect it to 'handle' like the Exxon Valdez...

[N.B. by the use of 'handle' I am referring specifically for the excessive requirement (IMHO) for steering correction at relatively modest speeds c.70 m.p.h., a tendency for the vehicle to be strongly affected by cross-winds, and what has been described by other forum contributors as a 'vagueness' to the steering or a tendency to 'wander']

An interesting viewpoint to suggest that Herr. Marshmallow who had overall responsibility for steering and suspension for the C-Class development at Mercedes Benz was pampering to one specific group of customers or potential customers. Who did they have in mind precisely?

What aspersions are being cast over the users of this, and other MB-related forums?

From your diatribe on C Class handling I can only conclude one of two things
1) Your car is in serious need of attention. OR
2) Your view of the vagueness is exaggerated.

My experience of MBs is that whilst they do not generally exhibit race car response they a VERY well suited to everyday driving. When MB produce a quick motor they do it very well a fact which is vindicated by the choice of the most celebrated of racing drivers. As an aside, I thoroughly enjoy blowing M3s into the weeds with my 225k mls 500E! (mind you it could be something to do with the pratts that generally drive them!!!!!)

500E
E320CDIT210

 

[Blobcat]

I regularly travel over the old and new Severn Bridges (usually just when leaving Wales, as I'm not all that keen on giving a French company £4.90 for the privilege of driving into Wales) and have never had problems with my 'E' wandering all over the road. I would really like to try some of these cars referred to in this thread as I have not noticed the problem in any of the 'C's I have driven.
If you want a vehicle that wanders all over the road then I would recommend a SIII SWB Land Rover on Cross Plies with a worn steering box (although a new box is not much better) .
Perhaps it is down to reference points. I have just been driving a Nissan Microbe for a week in Slovenia. Steering very direct and quite a lot of fun was had on the country hairpin bends. However on the highways any movement on the wheel could have the car all over the place.
Because of my off road experiences I only hold the wheel very lightly (off road when transversing ruts the wheel can rip your thumbs off) which possibly explains why I have had no issues with mine all the way up to 145mph.

 

[philharve]

Hi Blobcat

The cost of crossing the Severn bridges has risen again, has it?

I'm a member of several MB forums and steering 'vagueness' crops up frequently. I'm not sure 'vagueness' is the correct term but it conveys an adequate description of the symptom for the purpose of discussion.

Reading through the last dozen, or so, replies suggests to me that opinion is sharply divided on this subject. Is steering vagueness real or imagined?

I have no doubt it is real because there are a range of mechanical defects that will give rise to a sensation of steering vagueness. Surely no member would dispute this?

However, I have also noted the comments about PIT that argues the problem lays not with the car but with the driver. I can also accept this reasoning too because I am frequently called upon to drive a variety vehicles with which I'm not familiar. The transition can be a little disconserting.

Stepping from my C-class into another car frequently fills me with apprehension. However, on a long journey I usually manage to appreciate the car's handling characteristics and adapt my driving style accordingly. More often than not I detect an edginess in the steering which suggests to me that maybe the car has been designed with sports car handling in mind. The majority of these cars (lease hire) are almost new and therefore shouldn't have any mechanical or alignment problems. Perhaps this is the type of situation which can give rise to PIT: switching from a high performance car to a lesser one may create problems for some drivers. Maybe I'm one of them.

None of the cars I have driven recently, including my C-class, has held the road more confidently that my old Celica (may she rust in piece) up to its maximum speed.

My MB-trained indie informed me many months that the C-class doesn't possess the handling characterists of the E-class which must take second place to the S-class which seems to suffer no vagueness at all. Different steering & suspension design? Heavier car? Wider tyres?

The C-class has a fairly complicated steering & suspension design which I have no doubt is setup more for comfort rather than outright handling performance which must compromise comfort in these lower cost models. I accepted this possibility when I went from manual to automatic. I have never driven an AMG C-class which I assume must be tuned more for performance and handling than comfort? I've read that an M3 is still superior to the biggest AMG C-class in the handling stakes? Is this a design issue?

So is steering 'vagueness' real or imagined? I believe it can be either/both and it would be foolhardy to rule out either in any given situation. (IMHO)

If there is a mechanical basis for steering vagueness then there may be a remedy, simple or otherwise. However, if it cannot be remedied then you have either to live with it or choose a different type/make of vehicle.

If steering vagueness is imagined then maybe in time the driver can adapt to the car's different handling characteristics. Then again, maybe not.

I've had my MB for almost 18 months and it provides quiet & comfortable transport at all legal speeds. However, when pressed it exhibits a different character, a steering vagueness, which I believe has a mechanical basis. My C-class has covered 102kmiles so it is behaps not unreasonable to expect that it doesn't handle quite like a new car.

But I believe there is also an element of PIT in my particular case because I have become sensitized to this vagueness and in compensating my steering has become more twitchy, a bit like a rally driver but not so exagerated. This twitchiness, while not great, is enough to make me back off from going much beyond 100mph. My Celica, by comparison, would exhibit no vices right up to the maximum(131mph).

My experimentation with tyre pressures is paying dividends but I am aware that I may only be compensating for wear in the suspension components. I have been around vehicles long enough not to run around on under inflated tyres and I am closely monitoring wear, wall deformation and heating effects.

Prior to my experimentation I could not go much above 80mph because the car wouldn't track straight - it was ****** dangerous. Two psi lower all round and I can now reach beyond 100mph in reasonable safety. There's no noticeable heat build-up and tyre wall profile has not perceptably altered. Too early to report on wear though.

I think I have found a satisfactory compromise in my particular case but replacement of some of my steering & suspension components must be on the cards.

REGARDS Phil

 

[philharve]

Success!!!

Hi All

I'm now running around with tyre pressures 3psi lower in each tyre compared with that recommended for Continentals. I switched to Toyo T100Rs last year upon the recommendation of my friendly, local neighbourhood exhaust-tyre-battery fitter whom I've known for years.

There is no discernable change in tyre wall profile - 30 or 33psi look just the same - but the important thing is that handling is very much improved. So much so that I have attained 110mph without encountering any abnormal handling behaviour. However, putting another 3psi in each tyre creates an instability in the suspension system that makes even 80mph a hazardous target: the car feels like it wants to go anywhere but straight ahead.

Further speed testing is academic because I believe I have now proved my point and found the cause of the handling problem. It was a mechanical issue after all and not a psychological one, i.e. Pilot Induced Turbulence (PIT).

It would appear that inflating the Toyos to the pressures recommended for Continentals was not a smart move. However, it was easy mistake to make having not encountered such a problem before. I see no need to continue with the experiment and I will not be reducing the pressures further. I have found the optimum pressure values for my chosen tyres.

I wonder how many cars running around on British roads have incorrect/inappropriate tyre pressures? If a 3psi difference can have such a dramatic effect upon a Mercedes, what will it do to other makes & models of car? Or is the Mercedes particularly sensitive to tyre pressures?

I never encountered a pressure-related problem with my Celica but the whole experience has alerted me to the possibility that pressure induced instability may be a more common problem than I first thought. For example, I frequently drive hire cars on business and I often encounter a degree of steering vagueness in the majority of cases, regardless of make or model. I wonder if this vaugeness/twitchiness is symptomatic of over inflation by the hire company? Up until now I've assumed the edginess has been mt fault (PIT) and not the car's.

I don't usually bother to check the tyre pressures of hire cars if they look right but I do examine them for knicks, scuffs, cuts and other abrasions because hire companies are notorious for claiming against the driver for even the slightest imperfection. Fortunately I work for a large company which has a department that deals with claims, even bogus ones. I never give it a second thought.

REGARDS Phil

 

[COUPE FREAK]

well done phil,, glad you sorted your problem out,, think i'll have a fiddle with my tyre pressures and see what happens,,

 

[clive williams]

Hi All

I'm now running around with tyre pressures 3psi lower in each tyre compared with that recommended for Continentals. ........................................
REGARDS Phil

Hi Phil,

Strange? An increase in pressure usually sharpens the steering and I invariably increase the pressures on our cars for this very reason. Maybe what is happening is that the reduced pressure deadens the responsiveness, which feels like the vehicle is 'planted'

The only down side I see is that you ought to be more acutely aware of having the appropriate pressure in for the load that you're carrying at any one time. With a higher pressure less adjustment is needed for day to day variations

Clive

500E
E320CDIT210

 

[television]

Hi Phil,

Strange? An increase in pressure usually sharpens the steering and I invariably increase the pressures on our cars for this very reason. Maybe what is happening is that the reduced pressure deadens the responsiveness, which feels like the vehicle is 'planted'

The only down side I see is that you ought to be more acutely aware of having the appropriate pressure in for the load that you're carrying at any one time. With a higher pressure less adjustment is needed for day to day variations

Clive

500E
E320CDIT210

Clive, I am sure that it was you who said, that driving alongside another vechele was the best way to see how the shocker's are performing. this method is recomended in the trade.

Every MB I have had has always been very stable up to 130mph, and felt perfect and safe, with very little effort from me. My thoughts on this subject are that the higher the air presure, the more the wheels will bounce, maybe to the point of loosing contact with the road, hence instability. Soft tyres just stick down on the road and will mask the effect of faulty shocker's

There are several ways that a shock obsorber can fail, failure to damp out higher frequencies is one of them.

malcolm

 

[clive williams]

Clive, I am sure that it was you who said, that driving alongside another vechele was the best way to see how the shocker's are performing. this method is recomended in the trade.

Every MB I have had has always been very stable up to 130mph, and felt perfect and safe, with very little effort from me. My thoughts on this subject are that the higher the air presure, the more the wheels will bounce, maybe to the point of loosing contact with the road, hence instability. Soft tyres just stick down on the road and will mask the effect of faulty shocker's

There are several ways that a shock obsorber can fail, failure to damp out higher frequencies is one of them.

malcolm

Malcolm,

Yes, I agree. In fact, the high frequency damping is the most difficult to achieve and sustain in damper design and it tends to go off very quickly.

Clive

500E
E320CDIT210

 

[Rory]

It would appear that inflating the Toyos to the pressures recommended for Continentals was not a smart move. However, it was easy mistake to make having not encountered such a problem before. I see no need to continue with the experiment and I will not be reducing the pressures further. I have found the optimum pressure values for my chosen tyres.

I remember reading (but I've no idea of this is true) that one way to find the right pressure is to mark a broad chalk band across the tyre and then drive a reasonable (I suppose until the mark is worn, but not worn off) distance in a straight line.
Then adjust the pressure's until the wear is even.

I'll bet Malcolm knows if this is true or not!