I've done a search and uncovered a lot of info, but still unsure exactly what I need to do to fix my problem.

 

The issue is, that if I wind down all the way on the drivers side rear window, it seems to drop out of the rearmost runner (see pic). It stays put in the front runner just fine, and the motor/regulator seems to be OK as it winds up and down just fine the rest of the time, so long as you don't go to the very bottom.

 

I've had the door card off to do a bit of investigation, only to be greeted with a solid sheet of aluminium riveted in (see pic). This didn't give too much away...

 

I've seen a few threads where the window has either dropped into the door, or the regulator is knackered, but this doesn't seem to be my problem as the regulator is clearly working OK, and the window seems to be attached just fine as it works OK if you don't wind it all the way down.

 

Anyone got any ideas what has gone wrong, and how to fix it? I'd rather have a good idea what the problem is and how I'm going to solve it before I get the drill out and remove the rivets just to see what the issue is...

There's a cable driven by plastic gears which connects the motor to the window "frame". The teeth on the plastic gears can strip for part of the gear wheel meaning you get gaps in the window winding effect.

 

The main areas of failure I know about are connector corrosion (intermittent operation), motor failure (unusual), winder cable partial or complete failure (stick, jammed or inoperable window), stripped plastic gears (complete or partial failure to move the window glass).

 

Take a look at the part numbers on the motor and regulator and have a word with your favourite breaker or eBay.

 

Good luck!

Is it possible that the window is winding down too far? I've had a look at replacing the rubber window trim which has torn where the window has popped out of the runner, and it seems that the guide part that the window is popping out of is a part of this seal, as can be seen in this pic I robbed from ebay:

 

When the window pops out, I can manipulate it back into the guide by lowering it and applying some force, then raising it. I'm thinking, that when the window is wound down fully that it goes too far, and the top of the window comes out of the guide. Then when winding up, it doesn't find the channel and hence my problem.

 

So, what controls the distance the window winds down? Is it that it should just run out of travel in the regulator and stop? Or is there something in software that controls it?

 

 

On 27/08/2018 at 11:52, StickyMicky said:

There's a cable driven by plastic gears which connects the motor to the window "frame". The teeth on the plastic gears can strip for part of the gear wheel meaning you get gaps in the window winding effect.

 

 

From bitter experience I think this may be the cause. 

I've not had your issue, but having replaced an entire drivers door at the weekend (fitting my old door card, metal door membrane and inner hardware to a new door skin) I now have unwanted and intimate knowledge of how this mechanism, and all the others in the door, works!

As Mick says, on the reverse of the metal membrane panel thats riveted to the door there is a spool which has the cables that move the window up and down wrapped around it (which in turn are connected to two window rails and some pulley wheels). In turn, that spool has a small toothed gear hole at the centre, the window motor then connects to that through a hole in the door membrane.

 

Might be worth taking the window motor assembly off the door membrane, its only a couple of cables and three screws. Once removed you should then be able to see the back of the spool through the membrane, enough to see if any of the teeth are stripped out which I agree could cause one of the runners to slip. It looks to me in your picture that the window isn't moving that much and that would be about right if some of those teeth were worn.

 

Bad news is that if that is the case you are going to have to drill out those rivets and get that membrane off the door to get to the spool, you would also then need to reassemble all of the cables etc. (a rubbish job which I had to do after accidentally drilling out two of the rail rivets!). I'd share some pictures but stupidly did not take any of the back of the door membrane as I was up against time and quite frankly winging it when I did the work to mine!

 

From what I can tell you cant get the slide clips that attach to the window to go off the bottom of the runners/rails behind the door as the bottom pulley for the cable and a curved lip on the runner itself would prevent that. If you had gone off the runner there is also no way the window would go back up again, it would be jammed or off the runner.

 

Final option is that the plastic slide clip that attaches to the rail on the opposite side to where the window is falling in, has failed. One of mine was cracked and the plastic was quite brittle. With the tension in the cable system (which is considerable), if it has failed and cracked down the centre, for example, the cables could just be pulling it a bit further on that side as the tension works against a crack in the clip. You can check if the clip is damaged  as there are two inspection 'windows' for removing the window assembly in the door membrane. Have a watch of this video and you can see them and the the clips  are white plastic and right at the end where the window slots into place:

 

https://www.youtube.com/watch?v=gb8s7Lyh1Pw

 

 

Sorry for the essay

 

 

Well the window goes all the way up and all the way down - the issue is, when it goes all the way down (if I accidentally activate the one touch down, for example) on the way back up the rearmost edge of the window isn't located in the guide, it seems to pop out and travel up the outside of it.

 

However I do seem to remember the first time something went wrong it seemed to get stuck at a jaunty angle. Perhaps there has been some damage to the pins that secure the glass to the regulator?

 

I've done a bit of googling, and thanks to rawcas and StickyMicky's explanations I understand the mechanism/parts/how it all fits together a lot better now. Although the exact fault remains a bit unclear, I think the way forward is to get the door card off again, and see if I can inspect the securing pins on the window, and removing the motor to inspect the gears. Even if I don't uncover the exact fault, I'm sure I can eliminate a few things. I do have a cheapo endoscope, so perhaps with a bit of luck I can diagnose the problem without drilling out the rivets first!

Ok, so the good news is I fixed it.

 

The bad news is I dropped the inner pin into the depths of the door 

 

So, I got the door card off and had a look at the motor/regulator teeth. All good there.

 

Then I had a look at the pins holding the window to the regulator. No problems.

 

So with the teeth and pins all fine, what else could be wrong? I wound the window all the way down, and did the same with the passenger side window too. Both had the same amount of travel.

 

In the end I pulled off the inner trim strip and peering into the gloomy depths the problem revealed itself - the guide trim had gotten it's knickers in a twist!

 

I removed the window glass and straightened out the guide rubber, then sprayed it with a liberal dose of silicon lube. Then I cleaned the glass and slotted it back it. I got the big pin in without too much bother, but dropped the little one into the door. I spent a while trying to hook it out with an old coat hanger, and nearly succeeded, but with light failing and my tummy rumbling I decided to call it a day and finish up tomorrow. I should be able to get the pin out with a bit of blu tack on the end of the hanger, which I don't have any of at the moment.

 

I've tested the window a few times and it seems to be pretty good, but only time will tell if the kinked bit of guide rubber will cause problems in the future. I'll keep my eye out for one in good condition in the scrappy next time I go!

Great stuff. Glad you got it sorted.  Odd that the inner strip was twisted, must have gotten tacky with something maybe. Didn't even think of that TBH, on the front door it's not that integral to the workings. 

 

If you can't get the window barrell clips from the depths of the door I may have a spare one from the glass that came with my new door which I didn't use. Keep me posted and I can always send it to you if I can lay my hands on it.

Got the window back in, I didn't realise the way of getting the pin in was to fit it to the window then drop it into the holder! Worked like a charm. Door is all back together and the window is working perfectly (for now!), so my 8 year old will be able to open and close the window without having to remember to only wind it down half way

 

Thanks for all the pointers!