Welcome to our resource for MG Car Information.



MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB Technical - Roadster Windscreen

Any tips on fitting a roadster windscreen frame to the car, with all new rubbers!

Do you have to trim the bottom rubber where it meets the corner seals?

Colin Parkinson

The bottom rubber goes under the corner seals, so non-setting windscreen sealant is required on both sides of the corner seals. Shouldn't be needed on the bottom seal if the panel is smooth.

Firstly though you will have to make sure the packing for the legs in the body takes up all the free play i.e. the screen can't be moved from side to side, as well as there not being so much they won't go in. Adjust the packing side to side to the frame sits central with respect to the 1/4 lights when the doors are shut.

That bottom seal is a right pain. Probably the best tip I have read (but not tried) is to sit it in folded under, then slide a thin strip under the seal from the inside and push the lip out bit by bit working along. It's still going to be a pain pressing the frame down far enough to get the bolts started, probably easiest to tilt the screen forwards to get the bottom/front two in first, locating the holes with a spike, then using pointed bolts. Press the screen back and down carefully to get the upper/rear two aligned. Took three of us and big clamps, another tip read but not tried is to use a strap going over the frame and under the car (I think).

Try and remember to get the two centre bolts started before the frame is fully seated, although if you forget shortening them slightly so they go in, but pointed to centre the captive nut, and long enough to pick it up, will work.

For final alignment the front of the 1/4-light frames should just kiss the rubber seal on the frame sides, not deform it, for the whole length.
PaulH Solihull

All good advice from Paul. I think this is one of the hardest jobs. Definitely put the black non-setting windscreen caulk under and over the square rubbers round the legs. Excess will squidge out but it cleans easily with white spirit. The ratchet strap trick can help. Put a ratchet strap around the top of the of screen on each side and under the top door hinge. Gradually ratcheting them up will pull the screen down.

As for the bottom seal, it is terrible because it curls under the screen. I read of someone using duct tape straps along the rubber to hold it out the front, stuck around the frame. If you have a double thickness under the screen so it won't stick there, you can cut off the inside piece once it is bolted down and slide the underneath pieces out from in front. I intend to try this with my midget screen in a few weeks time.

Oh, and if you don't get the packing pieces right, chances are the screen will crack as you tighten the bolts... Before final tightening spend some time getting the fit against the quarter lights right, as Paul said.
Mike Howlett

When I replaced the bottom seal I place a piece of rope in the seal, had a friend sit on the windscreen, pulled the rope out and put the bolts in.
It wasn't quite that simple but you get he idea!!

This thread was discussed on 28/01/2012

MG MGB Technical index

This thread is from the archive. The Live MG MGB Technical BBS is active now.