FYI, while you are lubing and maintaining your wiper system, you might want to put a little grease on the spring detent that hold the wiper arm off the window. This is the detent that allows the wiper to remain off the window while cleaning the windshield at a gas station. My 87 got very stiff and I was afraid I would break or bend something when pressing the wiper back against the window. A little lithium or silicon grease works great and will last for another 10 years!

I must have a different setup. Under the wiper hub is a large rubber grommet/membrane and the surounding plasic. I can see no obvious way to remove the plastic to get to the control arms and the wiper hub retaining bolts? I'll have to takle this some other day as I need to figure out what the deal is.

Thanks for all the input guys, and Merry Christmas!

Superb advice from Silver Fox!
I wish I had read the tip first on releasing the cover to the slides; I have just managed to shatter the large cover on my C220 by prying a bit too energetically in cold weather. I had lubricated the twin-shafts about 12 months ago, with waterproof grease, which has turned out to be too thick in winter, and tends to stick sometimes.

A bit of encouragement for the faint-hearted, last year the nut holding the whole arm to the wiper drive came loose, so that the arm was not moving at all. You can imagine my distress at the thought of what this was going to cost me!! What's worse, I was due to travel 150 miles to an unmissable meeting the following morning, it was now 8:30 PM and getting dark, with heavy rain due overnight.

Desperate situation requiring urgent action!

I removed the whole wiper mechanism, just tightened the nut enough to hold the arm in place, then offered up the whole assembly, and corrected the position of the arm on the windscreen/windshield, then very carefully removed the whole assembly again and fully tightened the arm-nut in the right place. It was then straight forward to replace the whole lot back in.

This all took me only 1 hour and 45 minutes, with the car on the driveway, (garage occupied with rebuild project) and my long suffering wife passing tools and holding an inspection lamp. The hardest bit was removing the leaf shield without breaking any fiddly little plastic trim clips.

The point of the above, is to emphasize the comments elsewhere in this thread, that it is not difficult for a (supposedly) competent DIY'er to avoid big charges for wiper mechanism repairs.

1992 300TE Will this darn plastic cover over the base (Not the wiper arm attachment plastic piece) snap off/on or not?

Wayne gave step by step instructions with photographs stating to pry base cover from the sides and then guide he base via the hole nearest the driver (Where the wiper arm attaches) to remove the base.

For the life of me I cannot figure out how to pry the sides of the base up ???