Thursday, August 29, 2013

Diving Into the Door, Part 1

The passenger side window on my Z3 Coupe was slow... REALLY slow.  Especially descending.  It was so tortuous that I would usually reach across the car and help it down.  So, off to the Internet I went, and found some disquieting info.  This is an incredibly common problem on BMW's of the E36 vintage, and there is a real danger of severe damage.  There's a post welded in the door, which functions as a pivot for the window mechanism.  Let things bind for too long, and that can snap off, and then you're in a world of hurt.  BMW says replace the door.  Internet pundits say you can weld it back, after total disassembly, but who wants to get into that mess?


The conventional wisdom is to replace a pair of plastic sliders in the window mechanism.  At least they're cheap - I got four (enough for both doors) on eBay for $6.89 including shipping.  The disassembly process is well documented on the web.  I found these two links especially helpful - the first, for its very clear photos, and the second for its photo of the door card with very precise measurements of where to find the plastic snap connectors holding it on:

http://www.zroadster.net/forum/viewtopic.php?t=11887

http://www.unofficialbmw.com/e36/interior/z3_lets_remove_door_panel.html

That second link is by uber-guru Ron Stygar, and he calls out a couple of special tools.  Instead of those wild looking special pliers to remove the switch cover, I went with everyone else's recommendation, and just used a small screwdriver to pry off the switch and airbag covers.  He also recommended an Eastwood tool for removing the door panel, but I used a cheap plastic one from Harbor Freight, backed up when necessary with a metal pry bar to keep the tool from bending.

The reason those measurements are so important is that the door card is just cardboard, basically, and you can easily tear those tight fasteners right out of the door card.  The idea is to straddle the snap-in pin with a V-shaped tool, and then pop it out.  Pretty easy to do once you know where they are.

And the result - the door panel was off, with all seven snap connectors intact.  See the yellow circles below:


However, all was not well.  Part of the door panel remained behind - you can see the torn panel at the red circle.  Honestly, I am going to attribute that damage to the Previous Meathead - I would have felt that tear loose, and there was other evidence that I was not the first in the door.  Also, at the blue circle, the area around the mounting screw was torn out.  However, I definitely have to take the blame for the damage at the green circle.  Trying to get the two speakers out, I broke a plastic clip off the mount.  Darn brittle 15-year-old plastic - I guess that makes me the Current Meathead!

So, I used epoxy (JB Weld, since that was what was handy) to glue the clip back on, and to glue the missing part back to the door card.  I also made a custom washer from a fender washer to span the torn spot, so the screw could bear on the undamaged part.  It's ugly, but covered by the speaker grill anyway:


Once the epoxy set, I had a "perfect" door card once more:


Now, back to the door.  Below, you can see the door in a view taken before I fixed the door card.  The green circle shows the part that was later reunited with the door card, blue is the wiring for the speakers, and red is the big, bad airbag.  I disconnected the battery before removing that, but there's a "gotcha": if you reconnect the battery later (and you must, to move the window up and down), you'll set a code for an airbag fault.  Fortunately, I have an expensive code reader especially for BMW's that will reset that.  The Internet wisdom, if you don't have that, is to leave it hooked up.  I don't like working around bombs...



The foam weatherseal had to come out next, and the Internet had warned that the tarry goop holding it on was a real mess.  No kidding:


Actually, it's great stuff -still pliable after 15 years, and at the far end of the project, able to reinstall the foam without renewal.  I just used a utility knife to slice it loose, and set the shield aside.

The next step is stupid, I think.  Cars have broken side windows all the time, and I suspect that most manufacturers make it pretty simple to change them.  But not BMW... you have to remove the fixed triangular side window (the part that would have been an operable vent in a '62 Chevy) so you can remove and replace the side window.  And, of course, that totally destroys the adjustment of the windows, requiring much fiddling later.  But... out it came.  I forgot to take a picture.

And then... I was supposed to raise the window to access the bottom of the glass - but it wouldn't move!  It would "bump" up and down, but that was it.  I tried everything, and after about an hour, finally gave up in disgust.  Once home, I was furiously searching the Internet on my phone for any clue what I had done.  Finally, after about 20 links, I found it - a window reset procedure.  It goes like this:

1.  Remove the key from the ignition.
2.  Close the doors.
3.  Lock the car from the driver's door.
4.  Continue to hold the key in the lock position until the windows go all the way up.

We were eating supper while I was doing that, and once I found it, I said to Mary Ellen in my most loving voice, "Hurry up!  We've got to go back to the Grant St. Garage right now!"  See, the window was flopping loose in the frame, so I had to hold it away from the car while Mary Ellen did the key thing.  And it worked!  
Whew... enough for one night.  I went home and had a glass of wine...








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