Window Adjustment
- David Aiketgate
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- David
- mgf mk2 freestyle mpi 16" wheels, in Anthracite.
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This is taken from the excellent site
'Tony's Green Bullet'
Window Adjustment
Adjusting the Door Glass to get a good seal
One of the areas that seem to cause more problems than any other is that of the getting the door window glass to seal properly and prevent leaks. Whilst the Workshop Manual gives step by step instructions (see PDF files below) on how to adjust the glass, it fails to emphasize several of the more significant points.
Make sure that your seals are in good condition and change them if necessary.
The top and leading edge of the glass is meant to create the 'seal' rather than the inner edge.
When the glass is fully raised, it is meant 'pre-load' the seals - to cause the 'A' frame seal alongside the windscreen bulge slightly, rather than slide over it.
In a similar way, the top edge of the glass is meant to push into the lower edge of the cantrail seal.
Before trying to adjust the forward/backward or vertical limiting stops of the glass, make sure that leading edge is parallel to the 'A' frame. This is achieved by loosening bolts D and E, rotating the glass until parallel, then retightening them. Unless you achieve this, there is little chance of getting an effective seal.
Adjusters A and B are used to swing the top edge of the glass inwards or outwards, but there is a limit to how much this can be done.
Bolt G can have quite a dramatic effect on how much 'pre-load' can be achieved if it is badly out of adjustment. 'Preload' is the amount that the glass leans in towards the centre of the car.
Remember the more 'pre-load' you create will generate a better sealing effect, BUT too much will put a strain on the system and make it more difficult to close the doors.
The 7mm parallel gap is about the only direct measurement of the correct height of the glass when setting the glass stops C and F.
Note that the height stop E acts on part of the 'Glass Retention Assembly' and if the latter is too low in its adjustment the stop becomes ineffective. See Glass Retention Assembly below.
While you've got the door panel off, it's a good time to grease the rear sash and runners and pivot points.
The plastic lining sheets or water deflectors go brittle with age and split. When you're sure that the adjustments are correct and no more leaks are occurring, its worth replacing them. They are only about £ 4.00 each.
When refitting the trim, fit the door pull before you fit the door handle escutcheon. That way, if you drop the screw for the escutcheon, it won't drop down inside the door!
Good luck.
Glass Retention Assembly
There seems to be some confusion over how this assembly fits in the door (...at least I was initially!). If you look at how the manual displays it and labels bolts H and G, then look at how mine was assembled in the car, then bolt H sits below G in my left-hand door. The Retainer body of mine is clearly marked with an 'L' (left-hand?) so I assume it is fitted correctly.
The assembly is made up of several items, with the main retainer body and blue plastic adjuster having circular mating serrations. Adjusting these two either vertically up or down changes the pre-load angle. When the plastic adjuster is lower than the main body, the top edge of the door glass is moved in towards the centre of the car, increasing the pre-load on the seals. Moving the plastic adjuster upwards relative to the main body moves the glass away.
Window Adjustment
Adjusting the Door Glass to get a good seal
One of the areas that seem to cause more problems than any other is that of the getting the door window glass to seal properly and prevent leaks. Whilst the Workshop Manual gives step by step instructions (see PDF files below) on how to adjust the glass, it fails to emphasize several of the more significant points.
Make sure that your seals are in good condition and change them if necessary.
The top and leading edge of the glass is meant to create the 'seal' rather than the inner edge.
When the glass is fully raised, it is meant 'pre-load' the seals - to cause the 'A' frame seal alongside the windscreen bulge slightly, rather than slide over it.
In a similar way, the top edge of the glass is meant to push into the lower edge of the cantrail seal.
Before trying to adjust the forward/backward or vertical limiting stops of the glass, make sure that leading edge is parallel to the 'A' frame. This is achieved by loosening bolts D and E, rotating the glass until parallel, then retightening them. Unless you achieve this, there is little chance of getting an effective seal.
Adjusters A and B are used to swing the top edge of the glass inwards or outwards, but there is a limit to how much this can be done.
Bolt G can have quite a dramatic effect on how much 'pre-load' can be achieved if it is badly out of adjustment. 'Preload' is the amount that the glass leans in towards the centre of the car.
Remember the more 'pre-load' you create will generate a better sealing effect, BUT too much will put a strain on the system and make it more difficult to close the doors.
The 7mm parallel gap is about the only direct measurement of the correct height of the glass when setting the glass stops C and F.
Note that the height stop E acts on part of the 'Glass Retention Assembly' and if the latter is too low in its adjustment the stop becomes ineffective. See Glass Retention Assembly below.
While you've got the door panel off, it's a good time to grease the rear sash and runners and pivot points.
The plastic lining sheets or water deflectors go brittle with age and split. When you're sure that the adjustments are correct and no more leaks are occurring, its worth replacing them. They are only about £ 4.00 each.
When refitting the trim, fit the door pull before you fit the door handle escutcheon. That way, if you drop the screw for the escutcheon, it won't drop down inside the door!
Good luck.
Glass Retention Assembly
There seems to be some confusion over how this assembly fits in the door (...at least I was initially!). If you look at how the manual displays it and labels bolts H and G, then look at how mine was assembled in the car, then bolt H sits below G in my left-hand door. The Retainer body of mine is clearly marked with an 'L' (left-hand?) so I assume it is fitted correctly.
The assembly is made up of several items, with the main retainer body and blue plastic adjuster having circular mating serrations. Adjusting these two either vertically up or down changes the pre-load angle. When the plastic adjuster is lower than the main body, the top edge of the door glass is moved in towards the centre of the car, increasing the pre-load on the seals. Moving the plastic adjuster upwards relative to the main body moves the glass away.
David
:shrug:
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