PeachParts Mercedes-Benz Forum - View Single Post - W126 Rear Sunshade Repair Write-up w/ pics!

tinypanzer · #5 11-03-2010, 03:09 PM

Now we have to remove the old "rope gear" from the storage tube. In all likelihood, it will have broken right where the gear is. Grab it with a pair of needle nose pliers, and pull that sucker out! See picture 1. This is after I pulled it part of the way out.

Once it's out completely (see picture 2), you can see why this is such a crappy design. The plastic gets a big-time memory from the bend in the storage tube, and this creates friction, which causes it to eventually break.

At this point, I decided that I was pretty much screwed for the day. No way to get this part and put this thing back together on a Saturday. Or so I thought... A friend of mine mentioned that the "rope gear" looked just like the rope gear inside a Volvo power antenna. She just happened to have a broken Volvo power antenna lying around, so I figured "What the hell" and decided to break one open. See pictures 3 & 4.

Whaddya know? The two are almost identical. There were some slight differences; the gear spacing was different by a tiny amount and the notches in the gear weren't as deep as the original. However, I decided to give it a shot because it was so darn close. I don't necessarily recommend that you use this approach, it is probably far easier to order the correct part in advance of tackling this job, but in this case I went for it.

Either way, the next step is to feed the new rope into the mechanism as far as it will go. Start by inserting the rope into the gearbox and push it past the first gear. You may have to use pliers or a tiny screwdriver to get the rope to make that first turn around the gear, but once you get it past the gear and entering the storage tube, you're in good shape.

You can now re-attach the motor to the gearbox.

Take a 14v cordless drill battery, or any 12-14V source you may have which has adequate current available. Pry open the plug on the motor after labeling which wires go where. Remove the terminals and wire from the plug and peel them apart just a little bit to allow you to apply them to the terminals on your drill battery.

Make sure that the rope is seated all the way at the bottom of the gearbox, and is entering the storage tube. See picture 5. If it looks like this, you can go ahead and snap the nylon gear box cover back in place.

Apply 14V from your drill battery to the motor. If you are lucky, the rope will now retract into the storage tube. If you are unlucky, it will spit the rope out and you will have to start over and this time you will connect the battery in opposite polarity than before.

Retract the rope all the way into the tube until it stops. Then, cut off the excess, leaving about 4-6" extra. You don't need anywhere near that much, as you'll see in a moment.