MGB Windscreen Installation Part 1

Introduction:

Instead of creating a video for this installation, I've chosen to discuss some of the challenges I faced and share my insights on potential solutions. While there are numerous excellent installation videos available, some of which I'll highlight below. I took a slightly different approach. I'll outline these unique steps with accompanying pictures, aiming to simplify your process and ensure a clean, straightforward, and frustration-free installation.

Noteworthy Installation Videos:

• MGB Roadster Windscreen Frame Removal and Glass Fitting: An in depth guide 
• by David Russell-Wilks
• MGB Front Windscreen Screen Replacement Re-Fit 4000 Subscriber Special 
• by David Russell-Wilks
• 213 MG Tech | Sealing MG Windscreens
  
• By John Twist at University Motors

The Windshield Adventure:

Removing the windshield was mostly straightforward, except for dealing with the top two bolts. These bolts, designed by the engineers at British Leyland, are placed awkwardly against the edge of the metal dash. To remove them, I had to use a 9/16" wrench between the dash and the sidewall. However, as the bolt reaches a certain point, the wrench becomes unusable because the bolt head aligns parallel with the steel dash. At this stage, you need to use your fingers underneath the dash, combined with some careful wrench maneuvers, to slowly turn the bolt until it comes off. This wasn't particularly difficult but did add about 15 minutes to the removal process. I can see it may be challenging to re-assemble later on (see Part 2). The videos mentioned above cover this process well.

Once the windshield was off the car, I had no trouble removing any of the screws from the windshield frame, except for one missing screw and one stripped thread on the frame bracket. Rust can easily form on these brackets, especially if there has been water leakage over the years. Here’s my recommended preparation for this scenario:

First, if the screws are rusted or difficult to remove, I suggest using an Impact Driver, as shown in the picture, to loosen them and avoid stripping, which would require drilling them out. Fortunately, I didn't need mine as the screws came out easily, but this isn’t always the case. Having extra screws on hand, both the small and tall ones is advisable. They are inexpensive and can be invaluable when needed.

Once all the screws are removed, you can gently pull the sides apart. I had to start mine by using a flathead screwdriver, inserted between the top and side frames, and gently turning it to apply pressure and separate the side frames from the top and bottom frames. Once started, I could wiggle them apart.

At this point, it's essential to clean the insides of the frames thoroughly. The bottom corner brackets and top brackets may be very rusty, the threads might be damaged from previous installations, or they might be in perfect condition. Mine were not. Luckily, I was able to get two good top brackets from The Sports Car Factory nearby to replace mine. Additionally, I wasn't completely satisfied with the bottom corner brackets' threads, so I recommend having a set of these on hand along with new screws. Ordering a few extra screws is also a good idea, just in case.

Parts Order List from Moss Motors:

1. 408-075 and 408-085 - Left and Right Top Rail to Pillar Brackets
2. 408-050 Left and Right pillar to Bottom Rail Elbow brackets
3. 4 x 408-055 Bracket to Pillar screws
4. 8 x 408-056 Short Screws
5. 6 x 408-057 Long Screws
6. 282-420 Windshield Glass Rubber
7. I Used this Windshield: 458-815 Tinted Original Style Windshield

I took the time to thoroughly clean both the insides and outsides of the frames. My frames had clear silicone, some type of putty, and rust on the brackets. I started by using a flathead screwdriver to scrape off the silicone and putty, then used a Dremel to further clean the tracks and remove as much rust as possible. Below, you can see some before and after pictures showcasing the results.

Before

After

 

Once all the frames are clean, we are almost ready to start the installation. Now for the secret ingredient: replacing the rubber seal between the windshield and the car. This is where I significantly deviated from most of the notable videos.

First and foremost, the secret ingredient! Do not buy any other rubber seal from anywhere else but MacGregor British Car Parts. The website is MacGregor British Car Parts. It's a one-person operation, so it's best to call directly. Martin MacGregor, who worked at the car factory in Cowley, Oxfordshire, UK, as a Trim Development Engineer for over 14 years, has unparalleled knowledge of these cars.

I placed my order over the phone, provided my visa number, and received the seals two days later. Martin also offered valuable installation recommendations and advice, free of charge!

The rubber is sold from Canada. His rubber and tooling for the seal are unmatched. Don't bother looking elsewhere; MacGregor's products are superior to anything available at Moss or other British car parts suppliers. I had one from Moss in my garage, and it was stiff, it would cause much aggravation to seat and most likely failing to seal the water out. The MacGregor seal is pliable and seems like it will easily seat—this is yet to be determined, but it's very promising.

Here’s what MacGregor offers, and they are all superior products to what you can buy elsewhere:

• Windshield Seal
• Door Seals (that stay on!)
• Trunk Seals that won’t bow your trunk lid
• Vinyl piece cut to size for the top front of the dash, often damaged and best replaced when removing the windshield

By following these steps and using high-quality seals from MacGregor, you can ensure a smoother installation and better long-term results.

The MacGregor seal can be installed fairly easily by sliding it on, starting from one end with a generous coat of silicone. In fact, it might seem almost too easy. On my first attempt, I went so fast that the seal came off the track at one point without me noticing. On the second attempt, I slowed down and developed a system. It took me about 15 minutes to slowly slide it on. I used plenty of silicone lubricant spray on both the rubber and the track. My technique involved feeding the rubber onto the track with my left hand while using the weight of my right arm (elbow to hand) to inch the seal to the other side. It worked perfectly. It’s important to ensure that both the track and the edge are properly aligned into the adjoining slot (click the picture to enlarge and take a look).

The next step is to place the rubber seal around the new windshield. There's a trick to this. You'll notice that the window seal has some shaved or cut-off edges in four spots. These are designed to create space for the frame brackets during assembly. I positioned the windshield with the top part in front of me. When you look at the seal, you'll see a crack in one section. This is intentional and marks the center of the top part of the windshield. If you align this crack in the center, all the shaved parts will be correctly positioned. Take a look at the picture below. I measured out the center point to ensure accuracy.

We are now ready to assemble the frames together with the windshield. To secure the screws on the bottom, you'll need to pull off about two inches of the MacGregor seal. The videos mentioned earlier explain this process well. Use plenty of glass cleaner as a lubricant; it makes the task easier and evaporates later. Having new brackets and screws will simplify this part significantly.

Once assembled, I initially tried using a hook tool to put the two-inch seal back into the track after securing the screws (like in the videos), but I was hesitant to use it further in case I punctured the seal. Additionally, I couldn't manage to get it back into the track.

After taking a break, I decided to use a simple plastic tool designed for plastic body parts, and it worked perfectly. The technique involved placing one edge of the seal into the track, then lifting the rubber on the other side and using the plastic tool to gently force it into the track while holding the bottom edge firmly in place. This approach was instantly successful (see picture).

 

Next, I took the bolts and screwed them into the windshield multiple times to ensure they would go in easily during the final installation, as shown in the video. For the final preparation, I cleaned off all the old silicone and dirt from the windshield. With that, I called it a day. (FYI, that's why this is Part 1).

Stay tuned...