Window Cable Replacement
This Technical FAQ (How to...) has been carefully compiled by John Handford
My driver's window decided to stick at the top a few times and stop dropping on door opening. The motor was still working and the window could be freed off manually with a little dissassembly http://www.tt-forum.co.uk/ttforumbbs/viewtopic.php?t=52152&postdays=0&postorder=asc&start=20. This fix was only ever temporary, however, so I decided to replace the Bowden cable assembly which, as it turned out, had gone a little rusty inside and was spreading rust powder in the works. I also thought I'd document the procedure as there seem to be a few pitfalls to watch out for and it might help somebody else avoid them. If you think it's a little long winded blame Irving - he said make sure there are plenty of pictures!
The alternative to this fix is to replace the motor. The later ones are lower torque and less likely to jam. This may, however, only be a temporary fix if your cable is deteriorating! I have heard of some people having their motors changed a number of times by the dealer!
PARTS NEEDED:
* I managed to source a brand new driver's side cable for £29 delivered from www.AudiTTSpares.co.uk - Audi Pt/No: 8N0837462. Audi charge £76.45 inc VAT.
* 4.8mm diameter x 10mm long Stainless Steel blind pop rivets (Bag of 100 @ £9.80+VAT). Roebuck/Farnell part number 8871094
http://uk.farnell.com/jsp/endecaSearch/partDetail.jsp?SKU=8871094&N=401
* COMMA "White Grease" waterproof spray on grease - Halfords
* Halfords Silicone Rubber and Nylon lubricant
* High temperature insulation tape or similar.
* Horizontal lubricant
WARNING: Be careful not to short out the electrics. Loose connectors can touch protruding metalwork and trapped wires may get their insulation pierced. A short can burn out your wiring loom or even cause a fire.
WHAT TO DO:
Firstly, an important note: Make sure the window glass is fully up and not dropped at all. You can fool the door into thinking it's shut by sliding a screwdriver shaft sideways into the lock mechanism. Removing the motor connector will make sure it stays there. This is necessary for correct marking of the window glass later. If it's stuck down, don't worry, but you'll need to wind it up manually later. (N.B. The window stops against the lifter end-stops - not the window seal!)
Next, you need to take off the door pannel. This is detailed on Wak's excellent website but I'll go through it briefly here anyway.
Remove the rubber endcaps from the door by pulling out the rubber stud features. The one at the front comes off completely. The one at the door rear can be left engaged with the panel but removed from the metalwork. I've completely removed it here. If you do this, when replacing it, clip it onto the door panel first carefully otherwise you won't find this easy once the panel is back on the door and you'll risk splitting the holes. Lubrication makes reassembly much easier:
Next, remove the metal door handle cap. Wak describes inserting a thin rod up from below to release the spring but I found a simple twist anticlockwise worked without strain.
Next, remove the long Torx screw - the only one securing the pannel! The door pannel can then be lifted by the door handle but you need to disengage the door handle's Bowden cable from the rear of the door handle and also the four plug/sockets from the door wiring loom (wiggle and pull apart). Oh, and don't forget to retrieve the plastic strip that often sticks inside the door pannel - clip it back in it's proper place - the top of the door sub frame.
Now with the pannel out of the way, make a note of how all the cables are attached.
Now remove the motor connector by pressing the locking tab. You may find a small screwdriver helps for leverage. Before you pull the connector off, briefly press it further in - sometimes the lock sticks. I've exaggerated the outline of the internal locking feature that flips up when you press the tab.
Unclip the door handle Bowden cable by squeezing in the sides of the green plastic clip, then detach the wiring from the sub frame. I tried pulling the clips out of the holes but gave up. It's easier unwrapping the bits of tape that tether the cable to each of the plastic locating mounts - you can easily replace these separate bits of tape. There's also a solitary clip on a plastic extension arm.
Check you've not lost any of the little rubber jobbies that fit onto the door under each of the pannel hooks. Best clip them back on but they tend to fall off easily.
Now you need to undo the sub frame mounts.
Remove and retain the two little rubber covers over the sub frame angle adjustment screws at the side bottom edge of the door. Also, the three larger plastic covers over the bolts on the bottom edge of the door. They're a loose fit and just pull off.
Now, mark the position of the bottom sub frame mounts on the inside of the door with with felt pen or tipex. This helps to re-create the correct adjustment on re-assembly. You can also mark the upper top adjusters at both door ends before removing both lock nuts. Then remove the four hex head bolts on the door bottom edge and also the large locking nut for the height adjuster in the centre. You might want to mark the allen key bolt here too, although all this marking is not necessary if you plan to adjust everything from scratch.
Now you can pull the sub frame up and out of the door.
Now, with the sub frame out of the way look inside the door. There's a plastic wedge adjuster riveted to the box section at the position of the window guide runner (sorry no picture!). Pull it down to it's lowest position
WARNING: If you didn't manage to get the door window to wind fully up on the motor before you removed the sub-frame then you need to do it manually now before marking the glass. The cast aluminium mounting guides need to be fully hard up against the end stops with metal to metal contact, so that the glass edge forms a smooth line into the quarter glass. There are little pyramid shaped rubber buffer studs here (arrow) but they should be fully compressed into their mounting recesses and invisible in this position. If the window isn't fully up, incorrect glass marking and subsequent window lift positioning may result. If the window is fully up do not remove the motor before marking the glass. If the window is not fully up, undo the motor mounting screws and turn the motor assembly round (using it as a lever) to manually wind the window up as far as it will go before marking the glass.
Lay the door with the glass outside upwards. Mark the glass with a black marker pen along the guide runner edge and around all four securing washers, before removing the fixings, so the glass will come off marked like this:
You may find that the rear two securing washers have thin blue spacers underneath the glass on top of the white nylon mountings. Remember to put them back the same way:
Put the glass safely away for now.
Here, with the door sub frame stood upright, remove the three motor retaining screws BUT when removing the motor, poke a thin screwdriver down the back to ensure the pulley doesn't come out too! Otherwise this happens!!!
There is no warning in the Bentley manual about this and it's not a nice thing to happen if you don't want to scrap the cable. In this case we're replacing the Bowden cable assembly anyway, so this isn't important - but just in case you ever want to put it back together again, here's how:
Compress the two springs that tension the cable, either side of the pulley housing and wire them up like a Champagne cork so they stay fully compressed. This should allow you to wind the pulley back together without a fight.
Here's a picture of the pulley with one turn off. This is with the window fully wound up, so there's only one turn of the left hand cable end secured into the back of the pulley. The picture shows one turn of cable missing from the right hand cable end, which is secured at the front of the pulley (underneath in pic). The top of the pulley in the picture (with the ring of grease the motor pushed back) goes into the recess first - the face you can't see in the picture is outermost when assembled. Make sure all cable sheath ends are correctly seated. Add in that missing turn to fill the pulley and pop it back before releasing the springs. Then Bob's your uncle and Fanny is a very unfortunate name for an auntie.
Right.... back to the job in hand. Before we remove the bowden cable assembly, check the new one is the same and correctly handed. This is the new drivers side cable as supplied.
Now remove the clip-on support pad from the old assembly. Note the subtle asymetry - so make sure to put it back the same way. Also remove the cable loom support bracket from the rear guide - it clips off easily. Then remove the pulley moulding.
Removing the old assembly is a little tricky. You need to drill out the rivets with a sharp HSS drill or grind the heads off with a Dremel. Be careful not to damage anything espescially the holes - you don't want to make them any bigger! Be careful that the drill doesn't bite and spin the rivet round damaging the hole. Once the heads are off you can punch the remains out and spend the next half hour rattling the remains out from the sub-frame tubing . Only remove the rivets from the two black guide rails that come part of the new cable assembly. DO NOT remove the rivets from the long window runner guide rail that separates the main window and the quarter light glass.
With the two black guide rails de-riveted you'll notice that the cable assembly is trapped by the sub frame assembly - like interlocking rings - see the grey cable coming through the triangle formed by the window runner guide and the sub frame tubing. Don't cut the cable or remove the window runner. Instead undo this Allen bolt and slide the cable through the gap:
Before it's completely apart note how it goes together and intertwines. Remove the old assembly and intertwine the new assembly in the same way. Then tighten the Allen bolt.
Now a word about rivets. There are rivets and there are rivets . Don't use Aluminium ones as they are not as strong and they will corrode due to electrolytic action of dissimilar metals in a wet door frame environment. Use Stainless steel ones as were originally fitted. The ones you'll need are 4.8mm diameter x 10mm long blind pop rivets. Roebuck/Farnell part number 8871094 pictured below. As a warning - I first tried some 4.8mm x 12mm ones of a different manufacturer - they popped before they pulled tight and had to be ground off - a pain - they were too loose to drill out.
Here are both side by side - look much the same don't they? The Farnell one is on the right.
Now rivet the new assembly together. This is easier said than done! I'd like to think I've got strong hands but I was struggling with my Halfords heavy duty cast steel rivet gun. You need to use a good quality tool with interchangeable heads. A cheap pressed steel tool would be utterly useless. These stainless steel rivets are tough and pop with a hell of a bang. Use both hands and a stout pair of gloves to avoid damaging your skin or inflicting too much pain on the handle edges. What makes it tricky is keeping the frame assembly tightly together whilst heaving on the rivet gun with all your might! Make sure you rivet in a sensible order and don't leave yourself with a misaligned hole. Eventually you'll be rewarded with a rigid structure
Next, apply a little lubrication. Some of this spray on Comma "White Grease" available from Halfords, seems to match the lubrication that's applied already and it's waterproof. You can add a bit here and there for good measure including the black guides.
Then assemble the pulley moulding, the cable loom bracket and the clip on window guide.
Now to put the window back on but first a word of warning. You need to ensure the lifter is hard up against the endstops as mentioned before removing and marking the glass. Ideally reconnect the motor and drive the empty window to the top using the keyfob (if enabled). If that's all to much hassle at the moment, push the two cast aluminium sliding window mounts simultaneously up to the top, then reconnect the motor drive splined output drive to the pulley and twist the motor assembly round to tighten up the cable manually. You might be able to manage the cable becoming tight as the motor mounting holes line up - if so - pop the screws back in to hold it. Remember NOT TO PULL THE PULLEY OUT or you'll be sorry
Now, place the two blue washers on the rear mount bolt holes and rotate to align the peg holes for the lower steel washer.
Replace the glass by sliding in the edge to the runner (arrowed) and loosely assemble the washers and bolts - white nylon against glass and steel washer on top (lower washers have peg engaged in hole). Now slide the glass fully into the runner and make sure the window forms a smooth transition to the quarterlight glass. Then pull the window out from the runner by 1.5mm. The edge of the runner seal should now align with your marker pen line. Make sure it's parallel to the runner seal. Now make sure the washers are evenly encircled by your marker pen line - particularly at the rear mounting. Finally check the window edge alignment and tighten the top torx bolts to 6 Nm and the bottom ones to 8 Nm. Do not overtighten - even if these are the ones that come loose if you shut the door by grabbing the window and end up with wind noise! If you haven't already done it - tighten the motor mounting screws.
Next, apply some horizontal lubricant - a half time break - you deserve it!
At this point it's worth having a look at the subframe adjustment features in order to fully understand how they work. Here's a view of the complicated bit that adjusts both height (front and rear) and angle (gap between window top edge and door seal).
Just considering the rear adjustment, you can see that the lowermost bracket (outlined with Tipex) is clamped to the door with two locking screws (arrowed). With these two screws loose, the lower bracket and subframe is free to slide front and rear (the door has slots for these locking screws), as the two adjustment screws at the top front and rear of the door subframe are adjusted, which pull and push the whole subframe. This is the longitudinal adjustment. With the two lower bracket locking screws tight, the subframe won't move longitudinally, but with the height adjustment screw locknut loose, the angle can be adjusted by pulling the sliding bracket in and out with the thin adjustment screw. The height can also be adjusted with the big screw in between the two lock screws. With the height ajustment screw locknut tight, both the angle and height are locked.
There's also a centre height adjustment (arrowed on left below) - actually it's only meant for locking and providing strength. It should be backed off during adjustment, so keep it screwed in (up) for now, so the height is controlled by the front and rear adjusters.
So, put the subframe back in place. It may also help to reconnect the motor plug so that you can drive the window fully up and see if your window line can be confirmed before proceeding further.
If everything was in alignment before then all you should have to do is align all your marks and tighten the locking nuts . But if you had some wind noise before, or you've managed to loose the adjustment settings, here's what to do:
Throughout this procedure keep opening and shutting the door to check alignment of the window.
1/ First, align the lowermost brackets to the Tipex or felt pen. Do this by adjusting the top subframe longitudinal adjustment screws using an Allen key. Note that if you want to move the subframe forward you need to screw in the front adjustment screw and create some clearance, in order to allow the rear screw to push the subframe forward and take up that clearance - and vice versa. Make sure that the centre height lock (the one for strength) is still aligned with it's door hole slot - keep some thread protruding through. Once correct, tighten the four locking screws at the bottom edge of the door. Do not lock the top longitudinal adjustment bolts yet, otherwise you won't be able to adjust the height.
2/ Secondly, adjust the height front and rear. If your height was way out before, you may find correct height adjustment now throws out your longitudinal adjustment and you'll need to start over again. Aim for an even gap between glass and seal all the way round. Once your height is correct, do not tighten any height locknuts, otherwise you will not be able to adjust the angle.
3/ Thirdly, tighten the top longitudinal adjustment lock nuts. There is some play in the slots here so make sure front and rear are the same. Hold the adjuster screw from turning with mole grips or similar. Now you can adjust the angle and have the subframe pivot on the top longitudinal bolts. Try to adjust the angle evenly front and back and not twist the subframe unnecessarily.
The Bentley manual describes a small jig to cut out to measure the window top edge alignment. THE DIMENSIONS GIVEN ARE INCORRECT. Even this one I made, corrected for length, has too small a cutout gap. If you used it you'd get wind noise whilst parked!
Instead, I compared with the passenger door. It's easy enough to measure, feel and see the difference and get it the same. The glass should fit evenly around the margin and the angle should give a flush fit. Check the glass is set back equally in relation to the body trim along the window top edge compared to the passenger side.
4/ Fourthly, when the door and window close satisfactorily, lock the two height adjustment lock nuts. This will also lock the angle. Check everything is still alligned.
5/ Finally, screw out the centre height lock screw as far as it will go (until it meets the side impact bar aluminium bracket which rests on the bottom of the door). Then fit the washer and nut and tighten.
Now replace the adjuster covers, making sure that the drain holes are inwards.
Now, reach up behind the subframe and push that wedge up a few clicks as far as it will go, so it jamms between the door and the window runner - this should avoid rattles.
Replace the wiring loom the same as before. You can simply use some good quality insulation tape to replace the tatty bits of cloth you removed. The high temperature variety doesn't go gooey after a few years. Reconnect the motor connector (just push on firmly with a wiggle - no screwdriver needed) and secure the lock Bowden cable (that's it's hole next to it!)
Now don't forget those little rubber things - don't tell me you've lost them!
IMPORTANT: At this stage attatch the rear rubber endcap to the door pannel as it's a bugger to get on afterwards.
Make sure the plastic strip is on the top of the subframe and reconnect the electrics to the door panel. Then hook on the lock's Bowden cable. To do this easily, pull the internal handle so the eye pops out, hook it, then clip the white nylon into the moulding. Then being careful the door pannel hooks don't knock off the little rubber jobbies, lower the door panel into place, tapping into place gently . Finally secure the long through bolt.
The handle cap pivots into place like this and is secured with a clockwise twist.
Apply some Halfords Silicone Lubricant to the door rubber endcaps locking features to make their re-assembly easier. This is what the can only looks like from the previous temporary fix job (ignore what's being sprayed):
At this stage you should, if you've not done so already, apply a window reset to enable the window drop and one touch features.
Finally clean up everthing and after testing all is satisfactory, apply a little more Horizontal lubricant!
