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TR4/4A TR4 BACKLIGHT GLASS FITTING ISSUE AKA SURREY TOP

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Got_All_4

Got_All_4

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I have a fiberglass back-light frame on my Tr250 and I'm having a problem with the glass not permanently staying in. It looks like it's going to blow out at any time and I'm constantly adjusting the rubber glazing trying to pull it in and over the lips. When I first got the top and tried to install it I noticed that someone had ground most of the lip off on the bottom inside corners which leads me to believe they had problems trying to install it too. I rebuilt the corners and when placing the Plexiglass window on the frame for a dry fit, it looked like the window was too long. Like the ends needed turned in some more. It was a night mare trying to install. There is no manufacture identification on ether the frame or the window. I've been toying with the idea as a last resort to purchase a new window to confirm that the problem is in the shape of the glass. Expensive test. They're about $400. Anyone have any thoughts or ideas on a remedy? Has anyone ordered one of the new back-light glasses? Thanks Larry
 
My fiberglass surrey came with a flat Lexan window that I flex to install, not preformed. I have been toying with purchasing a new plexi formed window and have the same questions about fit that you are experiencing.

Is the shape of the window correct as it meets the inner lip (all around) that retains the rubber seal? Or is the problem just that the size of the window is slightly different?

Since fiberglass can have a quite bit of flex, are you installing the glass AFTER the backlight frame is hard installed on the car? Or have you tried to install the glass BEFORE bolting the backlight into position so that you can tweak the shape of the backlight a little to fit the glass?
 
THE SHAPE OF THE GLASS IS EXACTLY LIKE AN ORIGINAL PRESHAPED GLASS. IT LOOKS TO BE JUST A BIT TOO LONG. IF ONE COULD TAKE OUT A 5/16" STRIP OF PLEXIGLASS DOWN THE MIDDLE FROM TOP TO BOTTOM IT WOULD PROBABLY BE A PERFECT FIT. I DO SUSPECT THE WINDOW IS INCORRECT BUT HOW DOES ONE KNOW FOR SURE? I HAVE TRIED TO INSTALL IT BOTH WAYS. IT WAS MUCH HARDER OFF THE CAR AND IT TOOK 3 GUYS. THAT IS WHEN WE NOTICED THE PROBLEM. IT WOULD ACTUALLY POP OUT AS WE WERE FINISHED AND INSPECTING IT. I TOOK IT HOME AND INCREASED THE WIDTH OF THE LIPS IN CERTAIN AREAS AND HARD MOUNTED IT ON THE CAR. INSTALLATION WAS MUCH EASIER. WHAT IS THE WIDTH OF THE LIP THE RUBBER GLAZING MOUNTS ON ON YOUR FRAME?
 
I measured my fiberglass backlight and added the measurements to this jpg. All were taken on the bare frame at the center point of the lip that the seals fit on.

A - at the centerpoint of the lip, at the bottom of the apex of the widest part measures 44-1/8"
B - the lip protrudes 7/16" along the rear facing bottom horizontal most edge
C - the lip protrudes 5/16" along the top most horizontal edge
D - on each vertical side, the lip protrudes 1/4"

Also, the thickness of the lip caries becoming widest at points A. When these were made, they were molded in sections then joined together which might account for your width variation. Mine has needed a lot of filling from tiny bubbles in the gel coat.

https://mysite.verizon.net/kentech0822/triumph/surrey_measurements.jpg
 
Do you recall and can you describe the angle of the lip at the bottom outside corners where the longer radios is. That's where my biggest problem is. The picture is a big help too. Looks like mine may be angled in too much. Wants to pop out at the passenger corner first then the drivers side. Then it will start sliding off the top lip.
 
Do you mean the radius at the rear bottom or front bottom?

Also, since it's fiberglass, you can probably shave the lip to the angle you need and build it back up with resin.
 
Not the one at the door post. I guess it would be the rear. Just where it turns to go across the deck. The tight one at the posts fits quite nice.
I'm thinking the one I'm asking about is possibly tilted in or down too much causing the glazing to want to roll off the lip.
That is part of the lips I had to rebuild because most of the original lip was missing.
 
That could be a very big help. Trying to figure out that angle is tough. No one around here has ever even seen one of these tops. So I'm getting no local help. Thanks again!
 
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