Plastic guides on front door frames

[Birotor]

Some where Ive seen chat about the plastic pieces on the diagonal front of the front door frames asking what they do. These keep the window glass from being pulled out by the low pressure generated at speed. Back in the 1980s I nicked a pair off an LNA hire car I had in Greece for my GSA as at speed the windows wouldn't stay properly ín the felt tracks in the window frame and jammed as you wound them up especially in worn tracks..... Nothing to do with guiding washer water or rain....

[Dollywobbler]

Yet my Mk1 didn't have them and the windows never got pulled out. However, that is the most logical explanation I've seen for them (and I've seen a baffling number!).

[mat_fenwick]

These keep the window glass from being pulled out by the low pressure generated at speed.

Is that a known design function, or an observed effect? I've always assumed they were to direct water up the side windows, (as they do) but that could be a side effect of their intended purpose. I can't see how they stop the window glass from being pulled out though

[mds141]

IIRC Renault 19's had them as well.

[Dollywobbler]

Loads of cars had them in the 1980s and 1990s. Not so much these days.

[mat_fenwick]

Yeah, most of the cars I've owned have had them, and of the current fleet the Disco also has (had) them. I removed them to fit wind deflectors, and my windows have stayed in place so far...

[Way2go]

I thought it was more of an anti-rattle device than to keep the windows in place. Traditionally an area of turbulence, it is probably better these days of wind tunnel design for lower drag factors. Probably though, rattling would not have happened before other window components became worn too.

[Birotor]

Complained to my Citroen Dealer when I had the window winding problem in about 1981 on my GSA and they said 'Ah you need the little guides....' - after that I always assumed EVERYONE knew what they were for. The windows were were OK at 60 mph at 70 they were visibly being sucked out. Just got into the habit of slowing down to get them to go in at the full raised position...... Eventually saw them on a hire car I had (an LNA on Rhodes) and nicked them.

[Birotor]

RE: "Cant see how they work" comment. Sorry its pretty obvious if you do a little trial with worn grooves. Its not rocket science!

[Birotor]

In view of my sensing a degree of resistance to being believed - no doubt due to a 'not invented here syndrome' (which at my age I find increasingly).... I have got up off my butt and flashed up my Micro Fiche viewer and dug out my BX spares micro film sheets and there they are "DOOR WINDOW GUIDES"... end of I think.

[mat_fenwick]

In view of my sensing a degree of resistance to being believed

Not from me...just a genuine curiosity as to whether they were originally designed to guide water, and also served a purpose in keeping the windows in position as the runners wore when the vehicles were older; or vice versa.

The reason for my curiosity is that I've never suffered the problem you describe, and can't quite visualise what may happen. I could imagine the windows chattering in worn runners, but can't see how the plastic moulding (which doesn't contact the glass) would stop this? The metal part of it simply sits behind the window rubbers, and is so thin that it barely distorts them inwards. I was also puzzled why Citroen would fit these, if the only purpose would become apparent as the vehicle aged?

[Birotor]

Mat: Both of mine DO touch the glass on my 28,000 mile BX16 Estate - I've just been out and checked. On the GS as the window goes up, the gap on the leading edge closes and the glass gets 'caught' on the inclined edge and starts to get pushed in correctly lining up when it gets to the top and neatly slots in to the felt lined groove.
Looking thro' "La BX de Mon Pere" photos I only see them on Phase 2 models.

[mat_fenwick]

Ah...can you hear the sound of a penny dropping?

For some reason I was only thinking of the situation with the window closed! Yes, I can now see why the glass may need additional guidance (especially when at speed and/or worn runners) to go smoothly back into the felt groove.

[Dollywobbler]

Excellent. I wonder whether their subsequent deletion was due to better window mechanism design or just neatness...