W124 Wiper
 

I was wondering if there is anything that I can adjust to have the wiper arm exert more pressure on the windshield. The outer portion of the wiper smudges and does not do a good job of cleaning the surface. I just bought a brand new MB wiper blade insert.

Could it be that I installed it wrong? It seems fine, its only a piece of rubber ...hmmm I also use RainX, it helps a lot but still, I think the wiper blade should do a better job. The car has 108 k miles, the windshield is a little pitted from stones etc... that porbably doesnt help either.

Buy a whole new blade, not just the insert. They get weak with age and loose their "spring", so the outside doesn't wipe well. They also wear at the connection link, and start to thump and slap.

Peter

Also see this. http://www.peachparts.com/shopforum/tech-help/109671-came-old-thread-but-bright-idea-really-helped-me.html?highlight=wiper

The whole insert is very easy to replace so you might aswell go the whole hog as the other poster said.

I've got a theory on pitted windshields, I think they trap road grime and when it rains the water displaces the grime (as oil floats on water) and then the wiper smears it across the windshield. I occasionally wipe down the windshield with isopropanol and it seems to be better in the rain until grime collects again on dry days. My windshield looks like it is covered with pollen when looking at it from an angle because of 234,000 miles of pits in it.

Peter,
I agree about replacing the whole blade, at least from time to time -- I tend to replace the insert at least once or twice between replacing the whole blade--but I am confused about the comment about the "springiness" of a wiper blade. I just looked at mine and, when the insert is out, there is no spring in the blade, so I think the springiness is from the metal strips in the insert. I do agree that looseness in the various joints or pivots in the blade certainly does accumulate over time and causes problems.

I've also found that using the Bosch blades which are MB specific (and have "124" stamped on them, in my case) are better and more robust than the generic Bosch blades you get at AutoZone, etc.

Here's a related question: How often does one need to replace the actual spring-loaded "arm" which holds the blade? Seems to me that the spring would wear out over time and thus the pressure of blade on glass would probably go down over time. I have thought about replacing it, since like so many others I have suboptimal wiper performance, and some chatter at the bottom of the stroke on the driver's side.

I replaced the (original) arm on my new-to-me '87 300D a few months ago, at the start of the rainy season here in the Northwest. It made a HUGE difference. I think your theory about the springs is correct.

I hate the mono-wiper... it's my least favorite thing about the 124. When it's not working right it is downright unsafe, and when it's working perfectly it still isn't as good as the ordinary two-wiper system on nearly every other car. My plan is to replace the insert, blade, and wiper arm on a regular schedule as long as I have this car, to keep the thing working as well as possible. I'm thinking every fall for the insert, every other year for the blade, and every five years or so for the arm.

Alex,
Thanks for the info! I will order a new arm from Phil (here at FastLane) Monday -- I guess I'd be due after 11 years...

I COMPLETELY agree with your statement about the mono-wiper also being my least favorite thing about the 124 chassis. You are so right -- even when operating at 100% it leaves a lot to be desired. I will admit that initially I thought it was pretty cool, the way the blade hops up and down, but the novelty factor wears off quickly when you have a streaky, noisy wiper system, doesn't it?

Yes, exactly. :( The mono-wiper is the kind of thing that people always point out who don't like German cars because they're "overengineered." In this case, unfortunately, I think they have a point. It's obvious that a lot of design effort went into the thing... if you take the cover off the linkage and look at the gears (that's another thing you can do, BTW, to make it work better---clean and relube the linkage) you'll see that the way it's made is pretty darn clever... but the end result just doesn't work that well.

I was pleased to see that the latest C-class has gone back to an ordinary dual-wiper system like the 123. Unfortunately they seem to be sticking with the mono-wiper for the E-class. Makes the E320 CDI somewhat less desirable to me. (Not that I can afford one!)

If you are a bit of a DIY you might also consider lubricating the mechanism inside the housing every 5 years or less.

Sometimes wiper arms will benefit from a little forceful rebending. They can get bent or even twisted over time. A little rebending towards the windshield can do wonders.

BTW, I actually like the mono wiper. Of course, mine has not yet failed in any way. (knock, knock).

What helped me
 

I had problems with a chattering wiper in my 1995 E420 - drove me nuts. I kept having to switch the wiper on and off manually, because at the normal intermittent setting the niose was very annoying.

I read about teflon wiper blades being a possible solution, and bough one at Advance Auto parts (the entire assembly - not just blade). No chattering since. I've also put rain-x on the windshield, which is great - really reduces the need for using the wipers, especially at higher speeds. The rain just flies off the windshield by itself.

Troy
1995 E420 87k

My damn wiper blade is noisy too. I dont think its the wiper blade itself making the noise but the mechanism itself. Now I cant really find a thread dedicated to mono wiper cleaning etc..Can anyone tell me how I could clean the assemby and put some lube on it :P

Try this thread. :)