How to lubricate the wiper mechanism

[Parrot of Doom]

The wiper mechs on Mercs with single blades can dry up over time, which can lead to corrosion and eventual seizure. You can imagine what Mercedes would charge for a replacement!

Someone had already sprayed the outside of mine with copper grease, not a job I'd recommend as it is a grinding paste on parts like this, so I cleaned most of it off with the paper towel.

Here is the procedure, using my car:

Tools required - waterproof grease, silicone spray, paper towels/rag, long screwdriver with flat blade

1) Turn the ignition to position 2 and activate the wiper. Turn the ignition off when the wiper is in the 12 o'clock position (will take a few goes but its not hard).

2) Remove the keys and release the bonnet catch. Open the bonnet and depress the catch in the corner so it opens to its full vertical position. This will give you more room to work.

3) There are 2 bits of plastic that cover the mechanism. The first one is the smallest section, its easy to release. I forgot to take a picture but basically get your fingers between it and the glass of the windscreen, and tug both sides outwards. If your fingers are about half way up the bit of plastic, thats where the clips are. They're not big clips and it comes off easily. Once its free, it will rotate upwards around a pivot at the bottom of the wiper, just pull it up until it won't go further, and then pull it away from the windscreen (check the picture as I'm re-assembling it at the bottom of this page).

4) The larger piece of plastic is tricky. The first 2 clips are similar to the smaller bit of plastic. Get your fingers on one side of it, similar to above, and give it a couple of small tugs. You should easily find the clips, again they're only small.

5) Once you've found these clips, you'll notice that the big piece of plastic is still held on somehow to the wiper.

Remove the hex bolt just above the cover, and disconnect the wiper arm - be careful to shield the windscreen from the mechanism slapping down onto the glass.

I didn't need to do this, as the plastic on my cover is cracked underneath the hex bolt, so I just twisted it off.

http://static.flickr.com/73/204066577_c4a154425a.jpg

You can see the circular clip - there is a break at the bottom.

 

[Parrot of Doom]

6) Now both bits of plastic are off, you can see the mechanism.

Mine still had a bit of grease on, so either I've been lucky, they've used a miracle grease, or someone has serviced it at some point. Still, it could have done with more, so I obliged with Teflon grease (only grease I've got):

Once you've greased it up good, I gave it a bit of a spray with silicone lubricant to get to parts I couldn't reach. Once I'd done that, I reassembled everything in reverse order to above, and Bob's your uncle - one nicely lubricated wiper mechanism!

 

[rio678]

Wish i still had my 200T estate, as that one had completely seized

 

[Dosco]

Another excellent article. What I would have given for this article prior to a failure of the mechanism last year. Well worth doing as a replacement is an arm and a leg plus bits of other appendages! Fortunately I used to work for Bosch and obtained a replacement through contacts there, but even so it would have been a lot more cost effective to have carried out some timely servicing as described here.

 

[neilairman]

ball joint

at the motor end there is a ball joint. how would you lube that

 

[Blobcat]

Worth a read of these threads as well;
http://forums.mercedesclub.org.uk/showthread.php?t=25151
http://forums.mercedesclub.org.uk/showthread.php?t=23891

 

[C250TDSportAuto]

Excellent write up. I sorted mine today.

 

[whitenemesis]

Would have used the silicone spray first then the grease but otherwise good post.

 

[Willie]

202 wiper

I checked this before but havnt been using the car much since and never got round to to doing mine until last week. I have lubed up all visable parts because my wiper comes to rest 6 -8 inches from botton but lubing made no difference . What can I do next to get it to rest at the botton and is it difficult. Any advise would be great.
Thanks in advance

 

[C220GJS]

Willie ,sorry to hear about your problem, if your wiper is able to move in and out independent of the drive mechanism or has moved it's park position you will have to remove the complete wiper motor/drive unit,this link shows how ; http://members.lycos.nl/mbenz/windshield_wiper.htm ;.
There may be 3 reasons for lost or slipped drive if the motor is running,(1)the large nut on the back of the drive head or motor may have slackened (2)the nylon gear inside the drive head is slipping on it's shaft(3)the nylon gear has stripped. The first is just a matter of resynchronising the wiper and tightening the nut, the second can be repaired by drilling through the gear and shaft then fitting a roll-pin to stop it slipping, but if the gear has stripped the drive head will need to be replaced as the gear is not available separately.
If you need any more info. just ask.

 

[Willie]

Thanks for quick reply. I will just explain exactly what happens before I do any work.
First , the car is a 98 c180.
The wiper parks approx 6-8 inches from bottom. When it is turned on it moves to the botton and then continues the sequence perfectly. I would say it is a very strong, steady wipe with no drag or hesitation. My wiper is slightly different than that shown in the illustration in that it has two side shafts with the main one going up the centre !
Does this make any difference to the work I have to do.
Thanks n adv.

 

[C220GJS]

Hi Willie, the design of your wiper head makes no difference to the operation and synchronising of the setup. If your wiper park position has changed it must mean something has slipped in the link between the motor and drivehead, probably one of the nuts at either end of the link bar is not as tight as it should be.
Lubricate your wiper as shown to save further problems;http://202tech.mkosonen.com/howto/wiper.html.

 

[Willie]

Thanks for reply and info.
Before I attempt any work I will just say exactly what is happening.
When I turn the wiper on it moves down to the bottom of the screen and then continues the wipe perfectly and when turned off it comes back to rest approx 6/8 inches from bottom. The wiper moves across the screen in a very strong steady sweep with no drag or hesitation. The arm can be manually moved across the screen (ignition off).
The mechanism on my car is a little different than that shown in above pics.
The car is a 98 C 180 clasic model.

If I have to cary out the work how long SHOULD it take me. ....not a mechanic..
All the best & tks n adv

 

[C220GJS]

Should not take you more than an hour to remove the complete assembly, the difficult bit is releasing the clips at the front of the main grill section , the two at the centre are a pig just use a log flat screwdriver and be patient. Tools required;Philips screwdriver,10mm socket,long flat screwdriver or similar tool.Watch you don't drop anything under the wiper assembly or you could spend all day trying to retrieve it :razz:.
Good luck, just ask if you need help.

 

[Willie]

Thanks for info.

 

[turnipsock]

My wiper bits seem a bit different and look like the ones in the Haynes W124 manual. The smaller plastic bit doesn't flip off, but is part of the main wiper arm. There is a little flap that allows access to the bolt so that you can remove the arm though.

The larger plastic bit seems to be attached by screws from underneath. Even in the Haynes manual you don't see this removed anywhere.

 

[C220GJS]

I think this applies to your car Turnip ;http://www.mercedesshop.com/shopforum/showthread.php?t=66429 ;it's a long thread but i think all the information is in there somewhere.

 

[moore_887]

Did my wiper arm today. A bit clunky before i did it but running very smooth now. TThanks for the write up

Regards

Dave

 

[mattjb]

ello again trouble is back :wink: (me or the wiper ill let u decide:-D), my wiper motor works fine doesnt drag at all, nice an smooth on all speeds, only thing is its staying fully extended:sad:at all times any ideas

thanks

 

[Dec]

You should be able to push it back in manually, however it will most likely revert back again to the fully extended position, the reason is that the coged wheel in pictures below is slipping on its shaft.

The coged wheel is responsible for pushing out and pulling in the wiper blade, but because it is slipping on its shaft it is failing to pull the blade inward and so the blade hits the side windshield trim.

You have three options, 1 and 2 in Pic. Or replace the whole mechanism, but not the motor if it is o.k.

1…Drill a 2mm hole through the carbine fiber coged wheel, right through the shaft and out the other side, insert a 2mm Roll pin, cut to size so as it doesn’t interfere with the teeth of the gears, this will pin the wheel to the shaft.
Difficult to get a clean hole, as the drill bit is likely to break as the shaft is quite hard steal. The coged wheel looks and feels like steel, but it is some kind of plastic or carbine fiber.

2…The easiest and quickest solution is to tape a lollypop stick, TIGHTLY to the shaft as in Pic 2, this jams the mechanism, preventing the blade from extending and striking the windscreen trim, it won’t do any harm to the coged wheel as it is already slipping on its shaft and the damage is already done.

There is no keyway locking the shaft to the coged wheel, it is held in place by compression, you can see a rivet on the other side, looks a bit like a cross-head screw.
This fix will alter the sweep of the blade from an “oval” to an arc shape, but at least you can drive in the rain.

You can’t buy the gear, it just isn’t practical to repair, the alternative to the above is a replacement mechanism.

Dec

SEE ALSO...http://forums.mercedesclub.org.uk/attachment.php?attachmentid=4535&d=1200828405