I have had my 2004 SLK320 for about 9 months - its been a great, fun car. I have been I fixing all the little things here and there thanks a ton to this forum. A couple of months ago, the little rear triangle window on the driver side did not go up when commanded, but I heard a nasty little grinding sound -- so I tried to put the top down and then back up again...again heard some more nasty sounds and decided to stop moving things. It turns out that the little plastic pulley at the top of the window was pulled out of place and the cable came off it and was grinding around the motor. So I followed the good instructions at Pelican Parts (https://www.pelicanparts.com/techart...ow_Removal.htm
) to remove the window and saw the problem in detail. I posted pictures of the pulley out of place on this post.
Turns out you can't just buy that $0.25 pulley, you have to buy the whole assembly. So I bought the whole motor regulator and installed it - it seemed to work fine for a couple of months, but yesterday the same thing happened...so obviously I didn't fix the underlying problem - maybe I didn't get the alignment just right on the new one? I thought the old one broke just because it was 15 years old - but maybe there was an underlying alignment problem and I tried to match the new one to the old one and therefore its still out of alignment and just putting too much force on that pulley. I am not sure. But since the whole regulator and cable and pulleys were new, I am a little surprised.
Anyway, I was cursing the crappy design of the plastic tabbed pulley for that part anyway, so I punched out the center plastic peg and stuck in a 12-24x0.75" machine screw that I had laying around (I know US units in a Euro car, cringe...) That size threaded the inside of the plastic pulley nicely without drilling (M4 was too small and M5 too big). Then I added a nut for good measure -- I attached pictures of this too. I put it all back together (rerouting the cable and reinstalling the motor was fun - I also tried to take a picture to help anybody who might need to do this to see the cable routing a little bit).
While my screw certainly does not fix the underlying problem, it at least allowed me to close the window and will probably work for a while (until the cable snaps or something). Any ideas what might cause this to happen repeatedly? Both times it happened, it happened when the window was in the down position and wouldn't go back up. It doesn't seem like there is anything of consequence that would provide a lot of resistance to it moving back up (at least when it is at the bottom position - I could understand if it was hitting the top wrong).
I wonder if it could be a dying battery? On my list of things to do with this car is replace the hydraulic pump (Top Hydraulics rebuild) because the trunk and roof are moving slower and slower every time I operate it...there is no leak and there is a good amount of fluid - I think the pump is just old and losing power ... but maybe the car battery is getting weak and its affecting both the hydraulics and the window motor??? (no problem with the window on the other side, though) I am not sure what else could cause this little window issues.