Hello all,

Its already not an issue, but just want to share my experience.
I've recently bought 2010 S400 Hybrid from auction in Netherlands. My first 2nd hand car since 2007. Car was with original 179,000km (checked in online DBs and MB dealer).
Car was very dirty, but under the junk it appeared to very well maintained and in perfect condition.
Car was sitting in a lot since December 2021. All documents for maintenance since 2016 were in the glove compartment.
However I did full maintenance including all fluids, filters, gearbox oil, filter and seal, spark plugs, etc.
The problem was that in straight road car was pulling on right seriously. I went to two different shops for suspension convergence, they both told me - car is fully straight, there shouldn't be a problem.
After that another "specialist", told me that this is due to the tires, as the car was sitting for 7 months. Checked the tires balance twice in different shops - everything should be fine no issues.
I bought 4 new tires and checked the rims one again - still pulling right. Finally i went to 3rd suspension convergence shop and the guy told me - car is fully straight, but why don't go for suspension calibration.
He measured it and difference between front left ang right wheel was only 8mm. According to documentation everything below 1cm is acceptable.
But, this was my last option, and I've visited local shop specified only in air suspensions (recycling, setup, etc.). Initially they told me "8mm is not a problem, according to MB it is OK".
I've insist for calibration, and what a miracle - those 8mm after calibration made a different car. It is now running straight, there is no wheel spin in cornering with acceleration.

So I just wanted to share, as there are a lot of topics for w220/w221 pulling right, check the suspension calibration before anything else.
Hope this will help somebody

 

...interesting - two very different suspension types on these cars

posh ABC, far better, but has lots of fun - this can be out - but I'd expect the merc limits are less than 8mm on these cars, (but don't know), u can get to within 1mm
the standard and far more common airtraigic set up, the one I guess you have, and 10mm is a daily variance you see on old one's all the time

for airtragic three important first steps.... the calibration doesn't go out, it can't really, it is possible some idiot messed it up and so it might need doing (and indeed doing coz u want to is something you can do and many like to as the cars do appear to be lop-sided crazed rubbish much of the time)...

but its more likely some wear and tear is driving the issue - its possible a strut has worn, an air leak, a suspension arm bush has gone on holiday (very common on the 221), or the air pump has worn fighting a small leak (very common) and of course the insanity of it leveling the car when parked can give wild 2" variance (50mm in your world) from one shop to the next and convince you its lost the plot....

but before doing anything, the first three steps are always to check and 99% of the time replace the seized level sensor link rods - there is one each at the top of the front wheels, and one hidden at the rear on the left side above the park brake module, these link rods run on two 10mm mild steel ***** connected with a plastic ball socket that magically bonds to the metal with more success than super glue on skin


its quite possible (aka highly likely) at least one of your sensors is seized and about to snap off - and when replaced, the car will be lopsided and the work that didn't need doing, will now need to be corrected....you might be lucky - maybe the garage did the work correctly and fitted three new one's, before tampering with something they probably shouldn't be touching



.

 

Thanks for sharing your feedback on this issue . At first , I would also think that there should be something wrong with the tires possibly balance issue .
Good to see you fixed it
Happy Driving

 

A very resent experience. I lost my front left airstrut 350 miles away from home. Against all warnings I drove the car home and did not damage anything doing it. Had to be careful not to turn steering wheel too sharp to the left as the tire would rub on the fender, what a stupid design in my opinion that tire rub can happen.

Anyway, while driving the car it was pulling seriously to the left. I had to keep the steering wheel about 15-20 degrees to the right to keep the car going straight so after this experience I will check car level first before doing any alignment if car pulls to either side.

 

Thanks for posting. I took mine to the dealer for a four-wheel alignment about a month after I bought my 221 in January due to a rightward pull.

MB tech had it on the rack in the shop still when I asked if I could go back there and talk to him, which the service lady allowed me to do.

The tech said he had already aligned and driven the car but it still pulled right. He had Xentry hooked up so I assumed he did all his system checks and everything checked out. The tech said he really wasn't sure why the car was still pulling as it measured out perfectly while on the rack. We discussed it a bit then he pointed at the two rear el-cheapo tires as his next suspect, to which I agreed. I put two new front Conti's on it the day after I bought it because the tires that came with it were undersized, but I still have yet to mount and balance the two new rear Conti's.

So hopefully my issue is rear tires, which, although possible, just doesn't seem as plausible as something else. Both rear tires are cheap, but they don't actually appear to be in bad shape, which is why I'm still running around on them while the new ones sit on top of my freezer in the kitchen.

I still have to get under my car and clean/break free/service my level sensor mechanisms before BOTUS yells at me.

 

different game if its got ABC, the other type you can jack it up on the button by the speedo and reach in and try to wiggle the front link rods. But that rear one is almost impossible to see (unless the LHD cars do locate the park brake module on the other side of the car (right) - as some have said in the past. Every year for it roadworthyness test when its up in the air I try to lube the thing and I can never even see let alone reach that rear one

did you get a print out of what they measured? These days they have one total steer calc based on the results of all 4 corners. And some don't bother to get that at zero. Usually shows in the centre of the print out by the back axel.

I was driving a LHD Lexus in Netherlands a month back and that pulled quite a lot - RHD build country on LHD roads... whereas Mercs in the UK do the opposite (pull left). One would hope both were set to cope for the markets they sell them in.

 

another 5 pence worth

fiddling about I discovered some steering angel offset - not sure if related - on ABC cars they have cross wind compensation, which I guess is lopsided suspension stagger, it can do as it drives to combat high side wind forces
in some diagnostic stuff it seems to imply mine has this with Airtragic, I don't see why it can't (unless its the ABC individual wheel level sensors that can do it), but then again inside the strut it seems to know what each is doing as you can set up levels by changing each corners stance individually???

anyway what's this steering offset angle for ? maybe that's how they think they can make it drive to the left or right, rather than set up the suspension for LHD / RHD markets ? I reset mine but didn't notice it drive differently, then when I swapped R SAM it reverted to its old setting again

 

I doubt the Airmatic can react fast enough for transient crosswind gusts. I suppose they could play with the shock damping pretty quickly but not sure if that would do a whole lot for a cross wind.

Yes for road crown it was my understanding that a little bit of cross camber/caster can help but I am not sure you really see that in the manufacturer specs. It seems to be the job of the alignment shop to take that particular car and particular owner into account and fine tune but that's if you have a good alignment guy.

 

I did. I can post it if everyone wants. Until I get the rear tires mounted and balanced, and rule that out, (I'm waiting on that as I am going to have all 4 wheels refinished and CNC'd, along with all new tpms installed, then all 4 new tires mounted and balanced) my only other suspect was the braking system. The brakes do a lot of funky stuff automatically, like pre-brake when the car thinks you're going to collide with something, squeeze the rotors during heavy rain to keep the rotors dry, etc.. So certainly some computer glitch could cause the pull, but again, certainly the tech would have done all his related system checks with Xentry while he had it and he didn't mention anything of the sort so I didn't ask.

 

if you can up load it easily - I'd love see the numbers

 

Everyone loves an alignment machine print out.

 

I'll dig it up in the morning and post it.

 

Ran out of time today, I'm off tomorrow! I think it would be good info to post though, I'll make sure it goes up.

 

Hello again,

This is mine after 3rd alignment (Unfortunately it is in cyclic, but I've put "Before" and "After", other I believe is understandable from the picture.) I went to two other shops for alignment, both told me: car is fully straight, there should be a pulling. I I also visit 3 different shops to check the suspension, one of which owned of very close friend of mine - the verdict: everything is like new.
After this, car was still pulling right seriously, and guy, who made this last alignment told me: "man, this is car with complicated suspension, go and check the suspension calibration and steering wheel". Which pointed me to the real issue and fix.
The steering was OK, but those 8mm difference in the left-right level were the issue.
It is strange that, according to MB, difference till 10mm from left to right is acceptable, in real wife it was not.

 

Based on my couple of weeks experience , first check/fix the other stuff, and leave the suspension calibration as last step.

 

I can't find mine. I'm pissed because I know I kept it. I'll have to dig through some piles. Please hold!

 

I'm still not clear on what your solution was, what was off "8mm", and what "calibration" was done.

What was done to fix your problem?

 

Yes, those 8mm, fixed with suspension calibration, resolved the problem. Now car is running perfectly straight.

 

I assume he means the ride height was off. I don't really know how it would become wrong in the first place...

 

on cars its not one element of one corner (camber / castor / toe) that gets adjusted and you move on.... every single adjustment on any corner impacts all elements of that that wheel's geometry, and THEN any adjustment impacts the other three wheels stance due to compliance in bushings... and as its seldom done, seized adjustment can mean all manner of hell ensues to get one element to move, that shakes the whole car disturbing how its sitting and how the gauges sit on the wheels, moves steering wheel alignment and so on. They often have to heat a joint to get a thread to move and then the arm expands throwing measurements in the skip. Any adjustment need the vehicle to be driven for 1/2 a mile and it rechecked

then the w221 interior trim fools the eye, and this mostly means they ALL have the steering wheel offset as they start the job... and that on a modern car means they are doing it all wrong, as this thread suggests, the complex suspension set up (of any modern car) means the geometry moves deliberately as lock, roll and pitch comes in to play when driving. So when the ride height per corner is incorrect (often from seized link rods on the level sensors, and made worse by fiddly fingers touch ride height when it wasn't wrong till they touched it) it frequently means the starting point is wrong and in case all the luck in the world meant they managed all that - the vehicle selection often gets input incorrectly and or the software is out of date and the individual vehicle specific specs they are referencing are incorrect 60% of the time - e.g. LBW is different to the short one, RHD diff to LHD, this spec to that spec, these wheels to those wheels etc,

to do well is a slow skilled job - but the animals at tyre bodgers are us, tend to have no idea


as for below - the left rear camber is out of spec and he's nowhere close to mid way on most points... it was a nasty quick bodge up and the differences in front castor are a bit too big see the one beneath



easier in colour - one form someone elses post

 

I should post my sheet since that's what this thread is now. But for the record, mine was pretty close and I have no clue when it was aligned last. The base 18s probably help a little here...

 

Great, so you fixed it by "suspension calibration".

So how exactly is a "suspension calibration" performed?

Like squeezing blood from a rock here, throw me a bone!

 

I've written a huge load on doing suspension heights - Merc try to stop anyone outside their network doing the work by "insisting" the vehicle is programmed by numbers the operator see's from electronic measuring devices they attach to the suspension arms
they also make it so if the procedure isn't done correctly it doesn't actually store any adjustment values input long term - so lots with xentry think they have played but the next day is back to how it was.

it only goes out if fiddled with inappropriately or by wear and tear / lies form seized level sensors

 

just don't know how to do it
i'm here

 

Here's mine. No clue when it was done last. Tech said everything looked to be in good shape. Aligned no issues and doesn't look like he even needed to touch the rear. Just my local tire shop (but a good tech).