C200 Wipers

[max200]

My Single blade wiper on my C200 works ok when on normal speed but when on top speed the blade extends past the right edge of the screen and sometimes gets trapped under the edge.I know the arm does extend but should it extend to that degree or is it possible that the wiper blade I have fitted is the wrong one and too long?.
Also the sliding section of the arm is not sprung or does not appear to be, should it be?

 

[colechelle]

pull the arm right out and lube up the sharft, not un-heard off fault!!

 

[C220GJS]

This will show you how. http://202tech.mkosonen.com/howto/wiper.html .

 

[doversole]

Hi there,

I've just been outside and measured the wiper on my '202, it is 24" long.

You may just have bought the wrong size, they are cheap at the moment - see my post on 'Constant pressure wiper blades - a bargain'

Regards, DoverSole

 

[Dec]

You should try lubricating as suggested as this sometimes eases the fault however the only reason the tip of the wiper blade strikes the windscreen side trim is that a coged wheel inside the mechanism is slipping on its shaft, preventing the blade being retracting inwards towards the hub.

This fault is usually on the passenger side due to the centrifugal force from the sweep of the blade throwing the blade outwards, your problem for now seems to appear only when fast speed is in use, the grater the speed of the blade the greater the centrifugal force.

If the blade is the wrong one and too long for the car it would be striking/jamming on the left and right side trim of the windscreen. If as DoverSole has said, it is 24” long then you have the correct blade fitted.

The SLIDING IN/OUT ACTION of the arm is not sprung but the arm/blade has 2 heavy springs at the bottom to keep the rubber blade pressed to the glass, you can feel the spring tension by lifting the arm away from the glass.
The springs in any case wouldent have any bearing on your jamming fault.

See also post #20 here…

Dec

 

[cmax200]

Thanks guys, for the helpful advice. I have checked the blade is 24" but the sliding section of the arm allows it to strike the edge of the windscreen when it extends, and the arm does not retract, that seems to be the problem. I will give it a lube and see how that works.
Regards

 

[wireman]

It may be prudent to service the wiper assembly, open it up and re lube the innards of its hub, Parrot of doom has put the info on the DIY bit.

Also only fit the Bosch 24MB blade or one with a similar locking clip, without this clip the blade might detach itself and damage your screen.

 

[Aussie Nick]

I would agree with Dec .But all the other advice is valid too.

 

[dragon]

Not an easy job as written, the biggest problem is removing the cover.

 

[cmax200]

I have done as suggested, lubed up the sliders etc and they do move smoothly, however the end of the 24" blade still hits the edge of the screen and even goes under the chrome strip when I put it on top speed and the centrifugal force throws it out.
Any other ideas, I did notice there was a comment about a cog wheel but did not quite understand the posting. Perhaps clarifiication could be given.
Regards

 

[Dec]

I’ll have a go at explaining it again, how the whole thing works is quite complex and hard to get your head around at first glance.

They’re two separate mechanisms in the wiper assembly;
One moves the blade from side to side, sweeping the screen, yours is working fine and there is nothing wrong with that part.
The other mechanism is all of the “hub”, that is the in/out sliding rails that you just lubricated, the too are fine and working properly… BUT the coged wheel inside the hub (unseen except in above photo) is slipping on its shaft, it is not supposed to do that and therefor doesn’t pull the extended blade back in when the blade approaches the side trim and so strikes or jams in it.

Your fault is not too bad as it is only affecting the fast speed at the moment so for now the only thing that you can do is stop using the fast speed. However if the fault starts to appear on the slow speed, then you will have to take action by either;

1…Pin the coged wheel to the shaft as illustrated in picture.
2…Jam the sliding mechanism with a Lollypop stick as illustrated in picture.
3…Replace the whole mechanism but not the motor.

If you persistently allow the tip of the blade to jam and cause the blade to stop moving on the screen then this will result in damage to a nylon gear inside the motor so avoid using the fast speed.

What year is the car by the way?

Dec

 

[Aussie Nick]

Your artistic skill here Dec is only marginally overshadowed by your mechanical prowess of the 202 wiper mechanism. I would agree that this is the problem . It is the failure of the cog.
I suspect that this wiper mechanism will only deteriorate quickly from now on and may experience total failure in a rainstorm.
Accordingly the whole mechanism should be replaced forthwith. If my memory serves me correct the whole section, housing the cog, will need to be replaced as it is not possible to remove the cog and just replace that item.
I would suggest a trip to the Wreckers for a replacement part.

 

[zeaphod]

cogs away

The fix above has worked well for my friends MB and has lasted through plenty of use.

 

[cmax200]

Dec
Thanks for the solution, you cannot put a price on the advice.
Really appreciate your help and that of others.
Mind you I have had this problem for some years and its only now that I have decided to resolve it. Its a 1999 model and never been any trouble whatsoever, has been a first class car.
Regards

 

[Dec]

Hi Max, as your car is 1999 your sliding mechanism will be slightly different from the above but will work in much the same way. The best way of gaining an understanding of how it works and what is wrong is to remove the big black “turtle shell” cover and run the wipers at slow speed (on a wet windscreen) and observe how the sliding mechanism works, if you have a video camera, record the action and play it back at slow motion speed to study it.

Dec

 

[Dec]

Hi Aussie, I would agree that it will get worse, once the blade strikes the side trim, that is definite confirmation that the coged wheel is slipping on its shaft. However if he sticks to the slow speed it might last for a while.

It would be best to replace the whole mechanism, I doubt if a wrecker would sell just the hub section of the mechanism on its own as the will be left with halve a mechanism.

Dec

 

[C220GJS]

No need to replace the whole mechanism if the repair is carried out properly as outlined by Dec.
I drilled and pinned the slipping cog in my wiper drive head 4 years ago and have done others since without one failure to my knowledge.

 

[Aussie Nick]

Great stuff gentlemen. Now if I could just get you to tell me how to extricate the lower boom pin on the Excavator we would be travelling just dandy.

 

[C220GJS]

Use a bigger hammer.

 

[Aussie Nick]

Yeah Thanks GJS. I already thought of that. Didn't work. Any more bright ideas?????:idea: