Windscreen fitting – Midget, MGA, MGB Roadster

Fitting a convertible windscreen is a difficult job, but if you are reasonably handy you should be able to do it. All it requires is a bit of care, a lot of patience, and an average level of DIY skill.

Check all screw holes and screws are in good order before trying to fit –new screws are cheap and much easier than persevering with ones with damaged heads. Make sure the short screws are used to join the bottom rail to its corner bracket – if you use screws which are too long, they can contact the windscreen and crack it. If the corner bracket is badly corroded, it might pay to replace it.

Also check the condition of the bolts and tapped holes which secure the frame to the car. Sometimes the threads in the aluminium have been stripped – use a helicoil to repair them, the original thread is 3/8” UNC. (If you haven’t any of these, a local machine shop should be able to do the job for you.)

Lubricate all rubbers with rubber grease.

Fit the screen-body seal to the bottom rail before assembling the frame around the glass. It’s tedious – have a beer ready and be prepared to count to 10. Lots. Worth doing though as the old one will leak like a sieve if refitted (unless it’s relatively new)

Fit the glazing rubber to the glass, make sure it is centred.   (Check the page Fitting Windscreen Seals for further info)

Fit the top rail first, then the bottom rail, then the side pillars. With all these, push just firmly enough to get the rubber & glass moving into the groove then keep the pressure on as it slowly moves in. Keep pressure and support of the glass (on the opposite edge) as even as possible.

Have a couple of hulky helpers.

When fitting the assembly back to the body, remember to uncurl the lip of the new bottom seal. As it goes down onto the scuttle I use a plastic fishslice to poke the seal out by sliding it under the screen from the inside.

Maintain domestic harmony by remembering to clean rubber grease off fish slice!

MGB & Midget:  Tilt screen backwards (about 10 – 30 deg), engage the top bolts (hulky helpers needed for this) then push the top of the screen forward evenly, remembering to uncurl the lower seal as above, until the lower bolts can be fitted. Be ready to count to 10 lots more, it’s better than losing your cool and breaking the glass (we are happy to sell you another if you do!).

MGA:  Push the screen down until the holes line up and fit the bolts.  Hulky helpers might be needed for this too.  (If you think it is hard, Marty says that after helping me with a B one he’ll never complain about his MGA screen again!)

If all this sounds too much, it’s no easier for the professionals. Once I got lazy and got a windscreen company to replace a glass on my own B. Bad move, they cut the bottom corner off the glazing seal to make it fit, then didn’t bother screwing the bottom rail to the RH pillar. It leaked like a sieve.

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