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MG MGB Technical - windshield install

just got the windshield for my 79 b .I have the frame apart and getting ready for the install. Anyone have a install instruction sheet or some other place to go to for tech pics of how to install. I tried moss but they show only the side frame rubber install but not where u put the silicone and all other positions of seals. thanks ,Doug
dd doug46chief

Doug,

The professionals use sealant all the way round the glass. The key to success is the choice of sealant - it is not any ordinary silicone from the local hardware store - here in UK the repair shops have a range of materials that are not generally available. I went to our local bodyshop when I refitted the screen on our Roadster. Can you call on yours ?

Roger
R Walker

Agreed with Roger fitting a screen can be awfully fiddly. The screen on my GT looks new when I bought the car, certainly not original, nice job. Our locar glass replacement firm have got all the kit and know-how. Why not ask your local contractor? Mike
J.M. Doust

Doug,

Try this site:

http://www.chicagolandmgclub.com/photos/b_windscreen2/

and this site:

http://www.mgexperience.net/article/windshield-reassembly.html

One tip I could give you about bottom rail seal replacement. My parts seller, a MGB fan, told me it took half a day to slip bottom seal in its track and it was an horrible push'n-pull job.
It took me less than 10 min to slip it. I bought rubber lubricant, probably a silicon base extra thin lub which evaporate fastly. For CDN owners, available at Canadian tire. I liberately spray it on seal + track and voilą that seal was in place easily with a little of my friend ViseGrip to pull it.

Cheers,

Jean G.

P.S. Do not forget as others said to use urethane sealer
Jean Guy Catford

ROGER, when u say all around the glass do u mean they put it on the glass edge and then slip the rubber seal over it or do they put the rubber seal first on the glass and then the silicone in the frame track all the way around and then install the glass,the latter making more sense. I bought the silicone from victoria brtsh so it should be good. thanks , DOUG
dd doug46chief

My people didn't use sealant around the glass, or the glass seal in the frame, only under the apron seal. They also used the old-fashioned non-setting stuff, I would't use anything that acts as an adhesive as used on modern screens which have to be bonded to the frame as they are part of the structural strength.

It can be a huge job putting the frame together round the glass.

The next job is pulling the apron seal through the slot on the lower rail, needs lots of rubber lubricant and patience pulling it in, sometimes a bit at a time. Make sure you push it in towards the end, so it doesn't shrink back and make gaps on the car.

Next you have to make sure the spacer shims in the sockets for the frame legs are correct. There should be no side to side movement of the legs in the sockets, or when you tighten the bolts you can crack the glass.

Next tough job is getting a new apron seal out from under the frame and lying on the apron. Probably the best way is to push the seal through from inside the cabin with a flat metal ruler with rounded corners.

Getting the frame down and back far enough to get the bolts in is also a job, especially when you are trying to stop the seal curling back under. One thing that sounds like it might work is a ratchet strap over the top of the screen then down the sides and underneath. Tilt the screen forwards and locate the bottom holes with a cross-point screwdriver, then insert the bottom bolts, which should be pointed to aid starting. Then you can tilt the screen back to find the upper holes.

Adjustment of the screen is critical, the fronts of the quarter lights should only just touch the rubber seal down the sides of the frame, and there should be a clearance all the way between the side of the quarter light member and the thin rubber flange of the seal. Get these wrong and scuttle shake can be transmitted into the door skin and split it.
PaulH Solihull

Jean in the second site u gave me he mentions there is a top and a bottom to the seal around glass. How do i tell as there are 2 flat spots on the corners of the gasketnand one is longer than the other, also the center has a seam at on point where the gasket joins itself ,wondering if the seam goes on the bottom of glass. thanks Doug
dd doug46chief

Doug,
Paul has answered yours and I don't disagree with his advice but I followed the advice of a glass-fitter and used a sealant both sides of the rubber. Interestingly, I watched a professional replace the screen on a modern car and saw him use a transparent sealant in the same way. I have to say that some years back, I watched a French team replace a screen with no sealant between the glass and the rubber but they had already gone to great lengths to get a new rubber seal.

With respect to the mgb roadster, it is really important to prevent water ingress at the side of the skirt - near (and under) the pillars. The right kind ( flexible as paul suggested) in quantity as the factory did.

Roger
R Walker

Roger it looks like they used glazing putty in the corners. I guess i will do the same. I was wondering if the windshield could be replaced with the frame off the car but the frame fully assembled ? I would put the bottom gasket then put the end back on ,install the glass gasket in the channel and then using the string method to seal it around the the glass. If I remember right thats the way the glass co do it. Doug
dd doug46chief

Hello Doug,

I replaced it last year and as far I remember as winshield is some kind of trapezoid, I fitted seal to have flat spot in proper place. But last year I forgot to use any sealant and water is coming in at one point on right side of widshield. I will have to take it down next week to seal it.

For bottom seal ( apron seal for brittons) if you follow what I wrote it was an easy task. But having a helper is a +.

Cheers,

Jean G.
Jean Guy Catford

i am going to use electrical cable lubricant used to snake wires through cables and such for the seals. It washes off with soap and water and is clear. I WILL let all know how it goes when i am done. Doug
dd doug46chief

Doug - we wait with bated breath !!!

With regard to the practices of the factory - bear in mind that the designers of our car were both experienced and very forward thinking. The people who built it on the other hand, had their hands tied by the accountants and used the cheapest materials. Times have moved on and even more effective sealants are now available - which explains why many of our cars are even better than the originals.

R
R Walker

Just checking on something I might have forgotten to mark. The top rail has 4 screws, the 2 short ones go into the side post and the 2 longer ones go to the rail itself. In victoria brt they show a small one and a large one in the side post ,the longer of the 2 is closer to the radius of the side post. What would be correct as I dont want to shatter it when i put it together be hitting one of the screws. thanks Doug
dd doug46chief

Common sense indicates that the shorter screw goes where there is more likelyhood of a screw going through the seal into the glass. My screen has five screws each side, the inner four all have about the same distance to glass, only the outer one is past it.
PaulH Solihull

I Finished the windshield from hell. 5 hrs start to fin. No helpers. I could not remove one screw from side channel so i installed it with one in and the other next and last the top rail. Took 1 hr for that dumb ass apron seal even with the goop and the elect snake solution. put it on the car and letting the apron settle overnight and will bolt up tomorrow. I did try strapping the sides but there was too much flex so i gorillad it to get it to fit and used an awl to line up the top screws. If it cracks when i drive it ,its gonna stay like that. I am starting a list of things I wont do again and u guessed it , its no 1. Doug
dd doug46chief

This thread was discussed between 14/05/2012 and 17/05/2012

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