Window Regulator Issues/Rehab

[jeffwe]

[I posted this on Rennlist but got no response]

The right side power window on my 1990 964 Targa has been giving me serious trouble....

I removed the door panel and discovered that the window will go up and down under power if I grabbed the bottom of the motor and sort of pulled it toward the interior of the car. However, it would labor when doing this...

Without pulling on the motor it did not move and did not even seem like it was trying.

I have removed the window regulator mechanism and the motor. I've discovered the following:

- The regulator has a wound spring on it that seems like it is designed to help fight against the weight of the window. However even with the motor removed from the regulator the spring doesn't seem to pop the regulator into the up position like I thought it would. The regulator mechanism works but seems to have more friction than it should? I don't know how much it should normally have. Should the regulator spring pop it open when there is no window weight on it?

- The window track attachment to the bottom of the door seems broken. There is a bracket that is bolted to the bottom of the door that meets the window track, but the track is not attached to this bracket. I'm not sure what its supposed to look like when it isn't broken - is there an online parts diagram or anyone have photos?

- When I pull the window up and down without the regulator mechanism installed in the door it moves very easily at the top of its travel. However when pushing it down I encounter resistance. Should it just "drop" all the way down or is this resistance normal?

What kind of lubricant should I use where the window slides in the tracks? What kind of lube on the wheels of the scissor mechnaism of the regulator? What kind of lube should I use on the main gear/regulator teeth interface?

I don't want to waste money and buy a new motor and regulator if I don't have to. Anyone have experience with this stuff?

Thanks,
Jeff

[dtw]

1. The spring won't lift anything by itself - it is just a helper. Inspect the pivot pin that it rides on - is it deformed or broken? This is a common failure point as the cars age out, and there is a steel replacement from Weltmeister (available here at Pelican).

2. That sounds like the window frame depth adjustment. It should be bolted down - there are two pieces to the bracket then some fasteners. Try the parts diagrams in the PET or the PDF docs available from Porsche if you don't have the PET. Don't ask for PET on this board.

3. When free of the regulator, the window should move up and down with no resistance. There is a window guide at the rear of the door (near the latch) that is probably gummed up. Remove it, clean it, re-lubricate it, and try again.

4. I use silicon lube to lube up the regulator parts. You'll probably need to clean up all the mounting points where the regulator attaches to the window - the glass must be free to slide back and forth in the regulator. Like the guide mentioned in 3, the spring-loaded floating mounts also gum up over time.

[jeffwe]

Thanks for the good information.

I'll inspect and lube the pivot pin carefully. I didn't notice anything wrong with it when I took it out.

I've download the parts PDF from Porsche and found that the part that is broken is the retaining bracket part 911 542 061 00. I also seem to be missing some related hardware to that bracket.

I've determined that this broken bracket was the source of an annoying rattle noise when I closed the door, so fixing this will be a nice improvement.

Last question, what adhesive do I use to put the plastic sheet vapor barrier (I assume thats what it is) back on the door?

[dtw]

Yeah, I bet that door was rattling!! Make sure the parts aren't just rattling around in the bottom of the door.

A quality FLAPS should stock 3M spray adhesive - should be fine for the vapor barrier. You may find some self-tacking barrier material, though.

Another good while you're-in-there task - pull the door latch, inspect for wear, clean out old lube, and apply fresh lube. Makes it feel like new.

[jeffwe]

OK, I completely disassembled everything in the door. Removed everything, inspected, cleaned, and lubricated everything.

I've put the regulator back in the door and hooked it up. I am still having problems...

The mechanism operates completely normally until the mechanism reaches the upper or lower limit of travel. Once it reaches the upper or lower limit the motor does not respond to the switch unless I grab the motor and jiggle it (pulling it in towards the interior). This happens every time the window hits the limit....

Anyone ever seen this behavior before? Internal problem with the motor?

Also, what product do I use to replace the black rubbery goop that is used under the window frame joint rubber?

Thanks,
Jeff

[jeffwe]

Followup - In case anyone cares....

I replaced the motor today and all is well.

Now if only I can find a replacement for the window joint rubber that Pelican says is no longer available. And why is the window felt strip so darn expensive!!

Thanks,
Jeff