Glass | TVR M Series Manual

Windscreen - Removal & Refitting

The TVR M Series Bodyshell in the roof area has very little strength built into it - a simple steel tube of approx. 3/8" is bonded into the front pillars and over the top of the screen aperture. This keeps the roof in shape, but does little else for safety or rigidity. There is also a box section behind the sunroof aperture which is a block of foam or similar encased in the fibreglass.
The reason for mentioning this is that once the front or rear screens are removed, the roof and therefore screen apertures change shape slightly.

Does your screen 'pop' into or out of the car at high speeds?
You could say that the glass when fitted acts as the final strengthener, which would explain the fairly common fault of the windscreen popping in on the driver at higher speeds (or lower speeds on very windy days), or popping out (normally at the top)! To remedy this problem there are temporary and permanent solutions, but the two best ones are as follows:
1) Drive with a window slightly open to equalise the cabin pressure! Sounds a bit like an instruction for a aircraft, but with the windows closed and lower pressure inside the car, the flexible roof coupled with the poor aperture seal 'lip' can cause a scary moment. If this has happened to you I'm guessing you have the old style glass seal which is of symmetrical design? Remedy 2 will however solve all your problems:
2) Fit a new asymmetric window seal (see photo). This is identical to the original with the exception of having a wider outer lip on the outside of the glass. This allows a much larger surface of rubber resting on the bodywork, and also seals up most of the gaps found in standard rubbers (the ones you know about on rainy days)! The apertures cut by the factory in the bodyshell vary depending on the person who did it, and can be cut too short on some cars. See links page on this website for supplier - David Gerald Sportscars Ltd.

Black line indicates approx. position of front screen strengthener inside roof.

To remove the front screen, start by taking off both windscreen wiper arms complete with blades. Using a thin screwdriver prise out the filler (or tensioner) strip from the centre where it has a join. Pull out the complete strip, which removes all tension from the glass. Normally the screen will be able to be pushed out with just firm hand pressure applied from the inside of the car at the top of the glass. Have an assistant handy to stop it falling out completely and on to the bodywork, and once you've managed to free the top edge the glass and approx. ½ way down both sides, it can easily be lifted away. If for any reason it is hard to push out (probably because sealant has been used to stop leaks, or the rubber has hardened over the years) you may need to cut the screen rubber away where it covers the glass. On no account push it out with your feet (as you can do on a metal bodied car) as the roof is pretty fragile and stress cracks or worse could appear.

This is the replacement rubber filler I prefer for windscreens, but a clear plastic type is more common with a chrome effect inner which gives the screen a more classic look. The reason I use the rubber type is that it doesn't go brittle (so can be used for many years with frequent removal/refitting if necessary), is more flexible and therefore easier to fit, and also because I prefer the appearance.
The tool for fitting it is available from many restoration stores.

Fitting a new seal
Refitting of the screen rubber is fairly straightforward. To begin with clean all traces of dirt, old sealants and seals with a panel wipe solution (see bodywork tools section). This will provide a grease/dirt free base to allow the screen rubber to seat properly. Always use a screen rubber that's pliable and "grippy", don't use one if it's shiny and hardened as it will never seal the rain out, and you'll find it will only go in a certain place due to it having shape "memory".
A new rubber will come in a length rather than a square aperture shaped piece, so there will have to be a join. I prefer to make the join at the bottom as a leak here is easier to fix and less nuisance to the driver. Feed the rubber onto the aperture fully, being careful to prevent the headlining material slipping as you do so. Use masking tape to hold the top & sides in place as you work around - gravity will make it fall off if you don't! Once fully in, all you'll need to do is trim the end so the joint is straight (and hopefully hard to see). Use a sharp razor for this, as cutters will invariably make a non-straight joint.

Glass refitting
Place the base of the screen into the correct groove of the rubber, and centralise it (if necessary have an assistant give you a hand). Using a thin but non sharp tool (like the handle of a disposable craft knife), feed the seal over the glass all the way round. I use a water/washing up liquid mixture to help the knife handle slide along the seal. Without it you'll find it very tough going. Use of a sharp tool will split your new seal. Once the screen is covered, realign it within the seal until no areas appear to be under tension. As the roof panel flexes the corners tend to be the trickiest to get in the right place. You may also need to press the screen in with a fair amount of force to get the filler strip groove opened up slightly.

Filler strip refitting
Now for the most difficult job. The filler has to be fitted using the tool shown above, unless you like wasting a couple of hours fiddling around with blunt screwdrivers! Use a water/washing up liquid solution again to help the fitting process, insert the filler strip in the top or bottom centre of the screen, after threading through the fitting tool (make sure you get it round the right way too)! The fitting process is now a case of applying enough pressure to the base of the tool (so the strip is pressed into the seal groove), while at the same time moving it forward steadily to feed it in. Once you've got the hang of this it will take you about 2 minutes to do the whole screen. The corners can however be tricky and a few attempts may be needed without the tool slipping out of the groove.

Once fitted, check that none of the strip isn't fully in place, and wash the seal & screen with plenty of clean water to wash off the soap. Refit the wiper arms/blades, and hey presto!

Rear Screen - Removal & Refitting

The rear screen on the M Series TVRs is special in that it is extremely expensive to buy in glass, so many cars are fitted with perspex replacements (after a breakage or for track use). I'm not 100% sure, but I think the glass was to TVR's own design which explains its cost (I think over £1000 GBP now unless you're lucky to find one).

As I mentioned in the windscreen removal page, the TVR M Series Bodyshell in the roof area has very little strength built into it - a simple steel tube of approx. 3/8" is bonded into the front pillars and over the top of the screen aperture. This keeps the roof in shape, but does little else for safety or rigidity. There is also a box section behind the sunroof aperture which is a block of foam or similar encased in the fibreglass.
The reason for mentioning this is that once the front or rear screens are removed, the roof and therefore screen apertures change shape slightly.

For a replacement seal, use the newer designed asymmetric window seal (see photo). This is identical to the original with the exception of having a wider outer lip on the outside of the glass. This allows a much larger surface of rubber resting on the bodywork, and also seals up most of the gaps found in standard rubbers (the ones you know about on rainy days)! The apertures cut by the factory in the bodyshell vary depending on the person who did it, and can be cut too short on some cars. See links page on this website for supplier - David Gerald Sportscars Ltd.

Black line indicates approx. position of front screen strengthener inside roof.

To remove the rear screen, start by taking off both wires for the heated rear element (if fitted). Using a thin screwdriver prise out the filler (or tensioner) strip from the centre where it has a join. Pull out the complete strip, which removes all tension from the glass. Normally the screen will be able to be pushed out with just firm hand pressure applied from the inside of the car at the top of the glass. Have an assistant handy to stop it rising out completely and slipping on to the bodywork, and once you've managed to free the top edge the glass and approx. ½ way down both sides, it can easily be lifted away from outside. If for any reason it is hard to push out (probably because sealant has been used to stop leaks, or the rubber has hardened over the years) you may need to cut the screen rubber away where it covers the glass. On no account push it out with your feet (as you can do on a metal bodied car) as the roof is pretty fragile and stress cracks or worse could appear. With an assistant lift it away and leave it somewhere flat and out of the way. I treat this piece of the car as a priceless piece of art so I don't break it!

Rear screen removal - always get the help of an assistant as the glass can slide out sideways from its own weight and damage the surrounding paintwork.

This is the replacement rubber filler I prefer to use, but a clear plastic type is more common with a chrome effect inner which gives the screen a more classic look. The reason I use the rubber type is that it doesn't go brittle (so can be used for many years with frequent removal/refitting if necessary), is more flexible and therefore easier to fit, and also because I prefer the appearance.
The tool for fitting it is available from many restoration stores, and the M-Fix store will stock it soon.