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Old 11-07-2012, 08:37 PM
salbol1 salbol1 is offline
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Location: Kansas City
Join Date: Nov 2012
Posts: 32
Mein Auto: X5, 750il, 750Li
I'm in the middle of the pano repair - and based on what I've learned I'd budget 3 days to work on this. Here's some scoop on your concern, and some other general problems I've seen.

The 2 headliner panels are connected via a small knob that is the piece on the bottom of group 7 on the online ETK here:

When retracted, the rear panel falls into a small channel on a piece located in the "headliner repair kit" that's not shown on here. That small "knob" glides in the channel on the rear panel, and that's how the top panel glides over the rear panel. These panels are controlled by the rear motor - and act independent of the front and rear glass mechanism components.
The cassette has to be removed from the car to be able to reach this - or in your case you might be able to get away with removing the rear bolts while still attached to the frame - and loosening the other bolts to the point that the rear portion of the cassette can be lowered enough to complete the work.

Rear Vent Issue - window stays up:
This problem is caused by a small tab that located on the "Front Glass Mechanism Drive Plate" which is represented by the top part in Group 6 on the ETK. There's torsional stress placed on that piece which causes the tab to ultimately fall out of alignment with a small channel located on the bottom on the first piece in group 7 (Rear Glass Mechanism Drive Plate). When this occurs (the piece is aluminum that coated with a veneer of plastic which separates and cracks) the Front Glass drive plate stops aligning with the Rear Glass Drive Plate - result : rear window won't close from vent position. This also accounts for how this can happen 1 side at a time - and will ultimately lead to the other side breaking as well. This problem can be corrected by placing a "brace" in the rear of the "U" channel of the front drive plate -so that the torsional stress isn't transferred to the tab causing it to crack and fail. I secured a plastic formed brace via JB Weld - and it appears to be doing the job. BTW, cutting off the small triangular piece described by many posts from our friend down under on the Rear Plate is why you can still have the function of the front window venting, as well as retracting all the way back. That small triangle tab is the piece that connects those drive plates together when the tab from the Front Mechanism aligns correctly.

Another BTW - while the TIS links that QSilver posted are good - they by no means tell the story of how to do the repair effectively. Even the advanced information I was able to obtain from a BMW tech doesn't tell the story - and I have made mistakes doing the repair following this guide word by word.

I need to post some stuff to youtube to be able to show the workings of the sunroof and help "uncover" the way the mechanisms interact. The fact that the tab on the front drive plate warps like it does - and can effectively be remedied by a brace - has to be a conscious decision to not modify how this piece is designed. I spent $565 procuring all of the kits from BMA - and the time to do this is the killer. But given this can be done by DIY'ers at 1/10 the cost of a "full Cassette" replacement by the dealership has to be a "wink wink" arrangement with the OEM to design the parts good, but not "too" good, to help keep the dealerships flush with $5k repairs on these out of warranty cars. Or in your case, let's just disconnect the sunroof and not be bothered with it. The other thing that absolutely drives me crazy is the use of cheap, stupid plastic components in places that have some pretty intense stress (engine timing chain guide, window regulators, the sunroof, etc,etc,etc). I swear this has to be another "arrangement" for the dealerships to keep them flush with repairs. While I will NEVER be in the primary market for a BMW, you'd think that some of those people that eat all of the depreciation would bitch a little bit more - even though these repairs are covered under warranty for them. Even if you do have $100k+ to spend on a car - I'd think a bit more of engineering excellence would be voiced by SOME of those people - if not for the inconvenience it presents to them of having to drive a loaner while the dealerships fix their cars.

Last edited by salbol1; 11-10-2012 at 06:27 AM. Reason: mis-spelling
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