After years of the windshield wiper on my wife's 300TE producing one big smear across the windshield, no matter how many new wiper blades I installed, instead of a nice clean wipe I decided to overhaul the wiper system. I started by looking up the "jobs" relating to the wiper system on the Mercedes-Benz Model 124 Service Manual CD. I found the following jobs:
Job 82-0680 refers to job 83-040 Grille on air inlet removed, but my copy of the W124 CD Manual did not have the PDF for that job. Which meant I had to guess on how to get the air inlet grill off. After reading through the above jobs I decided the first thing I should do is remove the wiper system assembly from the car a take a good look at its condition.
After removing the wiper system, I found that the motor and wiper gear head where is good shape, but the the wiper linkage was worn out. This explained why there was about 3 to 4 inches of play in the wiper arm. The linkage had to be replaced. I also decided to replace the wiper arm and wiper blade. Here are a couple of pictures of the wiper arm:
I replaced the wiper arm because I have heard that over the years the springs get weak and do not create as much pressure on the wiper blade, which causes streaking. I also got some advice off of the www.mbz.org W124 mailing list that I should replace the wiper blade with a Mercedes original part. Here are the parts I order:
The first parts that I replaced was the wiper arm and wiper blade. This can be done with out opening the hood of the car, and takes about 15 minutes. The first thing I noticed was that the new wiper arm is about 1" shorter then the original wiper arm. This explains why the Bosch 40724 24" Micro Edge wiper did not fit on the 300TE before, at sometime along the way Mercedes shorten the wiper arm. The new wiper arm and blade are also black, the old arm and blade is more of a grey color. What I don't know is if the grey color is really faded black or was orginally grey. After installing the new wiper arm I then installed the new wiper blade, and find that the new wiper blade does not quite fit right with the new wiper arm. The wiper blade for the old wiper arm has the attachment point offset about and 1" from center. With the new wiper arm being about an 1" shorter, the wiper blade now is about 1" closer to wiper gear head. It does fit, but it is a close fit.
After looking in the EPC I think I know what is going on. Sometime in the early 90's the 300TE started to use the wiper arm part #124-820-43-44 (made by SWF) and wiper blade part #124-820-09-45. Mercedes quite making the wiper arm that originally came on the '88 300TE and replaced it with 124-820-43-44, which means I should have order a 124-820-09-45 wiper blade. Instead of ordering a 124-820-09-45 wiper blade, I went to the local parts store an purchased a Bosch 40724 24" Micro Edge wiper blade to install on the car. The Micro Edge fits and works great, no smearing or hitting on the car body.
Replacing the wiper arm and wiper blade made a huge
difference in the wiping of the windshield. I would recommend
to anyone with a 300E/300TE that does nothing but create
a smear across the windshield to seriously consider replacing the
wiper arm on their car. It's quick and easy, all you need is a 5mm allen
Next I moved on to replacing the wiper linkage. Replacing the wiper linkage took me about 2.5hr. This includes figuring out how to remove the air intake grill, removing the wiper system, replacing the wiper linkage, and putting everything back together. When reinstalling the air intake grill you might need some 3/8"x1/4"(WxD) weather striping. The intake grill has about 3' of weather striping to make a weather tight seal, and the weather striping on my grill was falling off and had to be replaced. Once you get the wiper system removed from the car, replacing the linkage is pretty easy. The only hard part was aligning the linkage such that the wiper parked in the proper location. Job 82-0760 tells how to align the wiper motor end of the linkage, and job 82-0760 shows how to align the gear head end of the linkage. If you are going to replace the linkage, you need this documentation, otherwise you are going to have a very hard time re-aligning the wiper system.
After replacing the wiper linkage in our 300TE, the play in the wiper went from 3-4" to about 1/8".
Here is a picture of the old and new wiper linkage. The old linkage
is on the top.
Here is a closeup picture of the motor joint (labeled A). The old linkage is on the left, the new on the right:
Here is a closeup of the center gear head joint (labeled B). Again the old is on the left and the new is on the right. Notice the gap on the bottom of the old joint:
And finally here is a closeup of the far right gear head joint (labeled C). Again notice the large gap in the old joint: