8Z0 898 738B Sunroof repair gears: what actually fails?

d4v1d sm4rt

A2OC Donor
Can anybody please tell me what actually fails when the sunroof stops working on a side, is it that these gears sheer off across the weak point or is it something else? See pic
101CD09D-BD18-4E40-9CD9-1B33418FC5BE.jpeg
 
Those are the repair parts, this photo from the German A2 forum shows how the original mounting breaks and where these repair items fit.

Screenshot 2022-12-02 at 15.54.48.png
 
Those parts don't break, they repair the broken parts. But they are not available from Audi any more. The photo in the post above shows what happens to a broken runner.
 
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My roof tilts up, but won't fully open.
The glass appears to open out of square and I get a lot of clattering from the motor, presumably when it can't grip the cables.
The motor mount looks ok, but I can't tell if the motor gear is worn.
Can anyone help with this please?
 
My roof tilts up, but won't fully open.
The glass appears to open out of square and I get a lot of clattering from the motor, presumably when it can't grip the cables.
The motor mount looks ok, but I can't tell if the motor gear is worn.
Can anyone help with this please?
The gear on the motor likely won't be worn, the motors are very robust. The mount will almost certainly have separated due to one of the internal runners breaking, causing the noise you're hearing. There's no way to tell if the motor mount is OK just from looking, as it only needs to separate a small amount to slip.
 
The gear on the motor likely won't be worn, the motors are very robust. The mount will almost certainly have separated due to one of the internal runners breaking, causing the noise you're hearing. There's no way to tell if the motor mount is OK just from looking, as it only needs to separate a small amount to s
The gear on the motor likely won't be worn, the motors are very robust. The mount will almost certainly have separated due to one of the internal runners breaking, causing the noise you're hearing. There's no way to tell if the motor mount is OK just from looking, as it only needs to separate a small amount to slip.

Thanks for the reply.
I haven't tackled a sunroof repair before, can you suggest a course of action please?
 
Ok, motor removed and the brackets behind, are not broken.
I'm guessing that the cables and motor drive are therefore worn out.
Can anyone please advise if these are replaceable and if the roof has to come out to enable access.
The whole oss was replaced under warranty in 2012, but I use it a lot,...
Thanks
 
The motor mount housing almost always looks fine. The aluminium mount separates just enough for the motor to slip, and needs to be replaced. The whole roof has to be removed to replace the cable ends too, not a small job. It's not really worth doing the motor mount or cable ends without the other part as most of the time both are broken.
 
The motor mount housing almost always looks fine. The aluminium mount separates just enough for the motor to slip, and needs to be replaced. The whole roof has to be removed to replace the cable ends too, not a small job. It's not really worth doing the motor mount or cable ends without the other part as most of the time both are broken.
Ok thanks.

As far as I can make out, the cable ends are still attached, but from what you're saying, the motor mount inside the housing, might be broken.
I'll have another look to see if I can narrow the fault down a bit.

Thank you.
 
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