Which sunroof seal for my '93 525i?

[DrCharles]

I need to replace the deteriorated sunroof seal on my E34. The realoem drawing shows two: 54121944649 and the "+0.5mm" 54128101158.
The one attached to my sunroof panel appears "fuzzy" but the replacements are apparently smooth rubber, too.

Which one should I order? Did BMW spec a slightly thicker strip to allow better sealing?

Also, I used the same -101 158 part number on the sunroof of my E38, but it adheres to the roof opening instead of the panel.
Can I stick it on the E34 roof instead of on the panel?

thanks
Charles

[GregT53]

I used 158 on my '93 M5 and it fits nicely. You can only mount these seals on the moving panel. Both parts have a felt like surface that is exposed on the top when installed. The seal should be set using an adhesive like 3M Super Weatherstrip and Gasket Adhesive. You may have to trim the length so take your time to make sure that the two ends, which meet on the back edge,make a clean, tight abutment (i.e. no gap). On resetting the panel (must be removed to install the seal) Bentley calls for a slight pitch: front edge is 1mm lower than back edge. Not sure why there are two seals, but I went with the +0.5 mm on the idea that it would provide a tighter seal. I believe both seals are comparably priced, at least they were when I purchased mine about four years ago. Take the opportunity to clean and lightly lubricate the tracks and inspect for broken parts; lots of plastic pieces.

[DrCharles]

Thanks for the comprehensive explanation (Actually I must have used a different seal on the roof opening of my E38 since it had a self-adhesive backing. No stickum required).

Best price I found was $83.33 from ECS Tuning with free shipping...everyone else was at least $12 more expensive, including the places that add shipping too.

[DrCharles]

OK, got the thicker seal and went to work this afternoon. In a word... no fun.

First off, the Bentley E34 manual removal instructions are wrong (at least for my 6/93 E34): there is no "locking retainer" to pry and release the front of the sunroof after loosening the front screws. The front screws also have to come out along with the center ones! The rear screws are correctly noted to loosen without removing as the sunroof mounting tab has an open end.

Once I got the panel off, removing the old seal was easy. But putting the new one on was a royal PITA, especially in the corners! My thumbs and index fingers are quite tired despite the careful use of a rawhide hammer to tap the seal into place. And of course, even though I measured more than once, I trimmed the seal just a tad short. That tiny gap will need a dab of black RTV at some point.

The new seal is so thick and stiff that the sunroof will not pass through the closed position to tilt without a push from below, so I can't adjust it properly. Some lubricant might help. I'm going on vacation tomorrow and will leave it in the hot garage (with the roof closed), maybe it will settle into place while I'm gone.

[GregT53]

Have a look at part number 54121938391 on RealOEM.com. This is the clip referenced in Bentley. It's a stainless steel spring clip that acts as a safety latch in the event mounting bolts loosen. My M5 is a 1/93 build and the 525 is a 5/95 build. Both cars have the clip. I would be surprised if they are missing from yours unless they were removed by a previous owner.

The seal should not make the fit significantly tighter; it's only 0.5mm additional thickness so a total of 1.0mm across both dimensions. Try cleaning the sunroof opening and lubricating both the seal edge and sunroof opening with a light coating of silicone. Did you set the rear edge of sunroof 1mm higher than the front edge? This slight adjustment may provide enough angular advantage to allow the sunroof to pop up in the rear without additional help.

[DrCharles]

That clip is not on my sunroof on either side... not only that, even once I got the panel off, I can't see any way that it could come off without taking the front screws out too. The front screws capture the mounting tabs. Who knows.

Yes, I mentioned using lubricant but am wary of silicones since the sunroof panel will need repainting some day and you can never remove every trace (tendency for fisheyes in the paint). Any idea what's in "Gummi-Pflege" aka snot?

[GregT53]

Gummi-Pflege is silicone free as is Wurth Rubber Care. I use good, old-fashioned glycerin to treat rubber seals. Available from my local drug store, about $5 for a lifetime supply.

If you get the panel set properly with the correct pitch I believe it will help free up movement for the pop-up function.