Sunroof frame seals

[TJ 450]

I have removed the sunroof frame/panel from my W126 for refurbishment. I'll be doing this on both of my 116s shortly as well, and they may even be identical.

Between the sunroof frame and the roof of the car is a foam seal. They are not very expensive from the dealer, but I'm wondering is there an alternative to this? It may be that when this foam starts decaying, it promotes rust.

I also found that the rubber seal across the sliding roof panel at the rear is critical. When in good condition, it channels some water off to the side drains in the frame. If it is dry and cracked, it allows water to overflow directly into the tray, thus onto the headliner and down the C Pillars, pooling under the back seat, as was my case!

Fortunately, there is no rust in the frame, or the roof structure. Just old dry seals.

Here's the frame, prepared for the new frame-to-roof seal, whatever that may be...

By tim_w116, shot with DMC-FX01 at 2009-07-24

By tim_w116, shot with DMC-FX01 at 2009-07-24

Tim

 

[Lukas]

Woohoo - a question I can answer.

I found that the old foam-like seal on the 116es was tacky on both sides - don't know if that was deliberate or a result of age. Anyway, I replaced it with a strip of black foam rubber procured frmo a store called Clark Rubber - http://www.clarkrubber.com.au/ - stores in most states and territories it seems.

The strips come in various widths and thicknesses - think mine was pretty much the same width as the metal strip on the tray that you attach it to (~15mm). Thickness-wise, I purchased a thin strip (about 4mm thick) for one part of the frame, and a ~10mm thick strip for the other part - it depends on how much of a gap there is between the frame and the car roof. If unsure, just get thicker - it will compress, but may make bolting it on a little harder (especially if you are holding the tray up with your head while trying to use a socket to put in the first few bolts - fun).

The strips also come in various different materials - Clark gives them all rating for moisture repellancy, rebound and UV-resistance, among others, so I just picked one with high ratings in the areas that I figured were important.

All the strips have adhesive on one side. Cost is about $2/m.

You are lucky to have a rust-free tray by the way.

Lukas

 

[TJ 450]

Excellent, thanks Lukas.

I'll head out to Clark rubber and see what they've got.

Adhesive on one side sounds brilliant.

Tim

 

[Styria]

It is a long time since I bought a genuine seal - probably some ten years ago, thus have no idea what its replacement price would be from the dealer. Whilst manufacturing techniques have no doubt been 'improved' in the last thirty years, I ask myself whether, in fact, one should use genuine whenever possible - especially if the price is reasonable.

The seal is not something that you replace on a daily basis, and when you do, it is a time consuming and awkward job - as you have alluded to, Lukas. BTW, have you guys managed to remove the sunroof frame from the interiors of the cars, or did you have to remove either front or rear glass ? My understanding is that one or the other needs to be removed.

Mercedes have, of course, used their 'special' foam rubber in various locations of our cars, and I am not so sure if that choice, or the quality of the foam, has been suitable for some of the applications, such as the front door trims etc. Incidentally, they never used foam on the rear doors - wonder why ? Anyway, my recommendation would be to go genuine.

I am also interested if anyone has found or located replacement side felt strips - the genuine price is crazy. Regards Styria

 

[TJ 450]

From memory, I think the foam seals are $20-$30 from MB. I don't think it gets much better than that, and all the rubber seals are available ex Melbourne for about $50 each.

I haven't refitted the roof yet as I also need those felt seals along the side. I do indeed think that it's one of those jobs that really needs to be done properly, with the proven genuine parts. I'm sure that the last thing anyone wants is a leaking sunroof after you've just refitted it.

Tim

 

[WGB]

I have one sitting in it's packet in my shed.
Cost was not an issue and I would be surprised if it promotes rust.

What promotes rust is blocked drains.

If a functional frame is fitted to a sound roof and the drains are clear the water level is unlikely to ever get above the level of the seal even though the edges of the seal may become damp.

The original seal is designed to fill a gap or compress to wafer thin and has all the necessary holes in it for the fixing bolts.

Be careful with rubber as it may give clearance issues with the height of the frame and stop the sunroof panel sitting at it's correct level in respect of teh roof line.

Another option would be a mastic of some kind but the original seal is cheap enough.

Bill

Bill