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MG MGB Technical - MGB Windscreen Bracket Question

Hello Guys,

I have a quick question for you regarding the small bracket at the base of the windscreen on the MGB. The picture shows the issue I currently have with this - hopefully the technology has worked and you can see! The car is a Heritage shell and the bracket sits about 3/16" back from the base of the screen. So, my questions are:

1) Has anyone seen this before?
2) Is it essential that the bracket is flush with and attached to the screen base or will having it fastened to the dash be sufficient?
3) Apart from the captive holes being in the wrong place is there a chance that the screen could be wrong i.e. too bowed or anything daft like that?

Hope you can help!

Cheers,
Paul.

P.S. Schofield

My immediate thought is that the screen is too far forward. There is a range of adjustment on the screen mountings to enable it to line up properly with the quarter windows. Have you got the quarter lights installed? If you have, do they line up with the screen? You can't tighten the screen down without the quarter lights being in place. The whole thing has be done together or you will have problems.

How do you intend to put the screws in the bracket? Generally one would put the screws in before tightening down the screen, because they are so hard to get at. The bracket is generally attached to the screen frame isn't it? However, I think it would work just as well being remote from the screen.

Of course, the holes in the Heritage shell could be in the wrong place - it has been known for such things to happen. I heard of one shell where the three holes that the steering column screw in to were in the wrong place, and that the radiator brackets weren't in line.
Mike Howlett

Hi Paul,

All I can offer is a photo of mine.

Herb

Herb Adler

Paul,

Mine sits s does Herb's, the lower windscreen frame against that sloped section on the front of the bracket.

Measuring straight line distance, in line with the rod, from the point where my lower windscreen frame contacts the rubber bottom seal to the top rear edge of the plenum chamber chrome insert I get 68mm.

That might help determine if your screen is mounted too far forward and, if so, by how much you might need to adjust it.

Hope this helps.

Regards
Roger
Roger T

"The bottom rail assembly carries the lower sealing strip and the centre rod bottom bracket, which is rivetted to the rail and bolted to the body." WSM

FRM
Fletcher R Millmore

This bracket should be riveted to the bottom rail of the windshield, but it's primary function is to hold the top rail down against pressures exerted by the top/hood (not hood/bonnet). (OK, on early cars it has another important function; i.e. holding up the rear view mirror.)

I have one car in which these rivets pulled loose, and I've not noticed any leaking under the body/windshield gasket.
Dave McCann

If it is rivetted to the rail, all stresses are edgewise on the glass, in compression; if not rivetted. it's pulling the center of the glass in bending.

FRM
Fletcher R Millmore

I don't think the rod really stresses the glass. It doesn't compress the top and bottom of the windshield frame together, it just keeps it from separating.

Like I said, I've got a car that's been that way. It's been a couple of years, and it's not caused any additional problems.

As I'm thinking about it, the top on that car may not be that tight. It might be more of an issue if the top is really pulling the windshield frame.

Just leave the top down all the time, that's what I do.
Dave McCann

Hello Gents,

Thank you all for your help - it does look as though a refit is in order, but at least I know what to aim for now.

I'll probably be on again with more questions; in the words of some bloke on a film - I'll be back!

Cheers,
Paul.
P.S. Schofield

That bracket should be rivetted to the bottom rail of the screen - but just to stop it getting lost, it is the bolts to the dash that secure it and the rod to keep the top rail in position under hood stresses. Caged nuts below the dash top cope with fore and aft adjustment of screen to body. With the screen that far forward, if you haven't got the 1/4-lights in position you may well find there is a huge gap between screen and 1/4-light. It's primarily that setting (front of 1/4-light jusst touching the screen seal, not compressing it) that determines the fore and aft position of the screen and its rake. The 1/4-lights can't move fore and aft in the door as I recall, just be adjusted for sideways tilt (and alignment to the screen) using the bottom of the front channel. The door hinges could be used to adjust 1/4-light to screen of course, but they are primarily to get the door correctly aligned with the wings.
Paul Hunt 2010

I moved my quarter lights very slightly fore and aft (well more to get the rotation right) by putting small washers between the vertical front leg and where it bolted to the door frame. Only about 1mm or so but it made the fit much better.
Simon Jansen

Paul Hunt is right on. It appears that your W/S is angled too far forward. Check the glass and you should have "approx" 42-44 degrees from vertical. Mike Howlett is correct, i.e., the bracket is riveted to the lower W/S rail but it's really just for locating the W/S assembly. Used two SS 1/4"x 1" NFT hex bolts to secure the bracket to the dash. Unfortunately, you put the W/S assembly on before installing and securing the rod into the bracket base. The rod, as mentioned by everyone, is to secure the top W/S rail. Make sure you DO NOT over tighten this rod. Super snug is fine. You don't want to rick cracking the glass at this stage. Paint the rod flat black prior to installing to prevent it from rusting. And 'rust" it surely will after a few outings.

Under no circumstances should you ever mess with the door hinges to align the quarter vent windows to the W/S pillars. This would be a big mistake. The factory had specially made jigs to install these doors.

Secure the W/S assembly with all bolts and fasteners and align as necessary. Then tighten the bolts after proper alignment. Two people are necessary for this operation. Get the wife to stand in the car and gently press her body weight down on the top W/S rail whilst you are securing the W/S posts (pillars) evenly on both sides. Snug the bolts and then double check your alignment.

Smear the bottom W/S seal with baby oil or Vaseline and use a Craftsman cotter pin extraction tool to pull the rubber flange forward before compressing the seal to the car body. Voila, you are done.
R Murray

This thread was discussed between 03/04/2010 and 09/04/2010

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