Replace Speedometer Lens
Thread Starter
Safety Car
Joined: Sep 2013
Posts: 4,355
Likes: 2,631
From: Draper Utah
Replace Speedometer Lens
1970 Corvette, 4 spd, with AC
What's involved in replacing the speedometer lens? My lens is a little cloudy. I have to replace the headlight switch in the near future, which I understand includes lowering the steering column so you can gain access behind the lower dash pad. I figured why I was there I'd replace the cloudy lens if it's not too much more trouble.
What's involved in replacing the speedometer lens? My lens is a little cloudy. I have to replace the headlight switch in the near future, which I understand includes lowering the steering column so you can gain access behind the lower dash pad. I figured why I was there I'd replace the cloudy lens if it's not too much more trouble.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,112
From: Crossville TN
Removing it is a real PITA. You can clean it then polish it with basic toothpaste or a fine grade of polishing compound. Then, clean it off again and give it a coating of Nu-Vinyl or Meguiar's protectant for plastics. That coating will fill in any very fine scratches that are still present.
I'd hold off on replacing the lens until you absolutely have to get into the speedo/tach area.
I'd hold off on replacing the lens until you absolutely have to get into the speedo/tach area.
Thread Starter
Safety Car
Joined: Sep 2013
Posts: 4,355
Likes: 2,631
From: Draper Utah
The problem is the speedo had moisture in it at some time in it's life and the lens is cloudy on the back side. The previous owner drilled a small hole in the lens to let the moisture out. You can't see the hole unless you look for it. I can live with the cloudy if it's difficult to replace. I was just hoping it was something simple if I had the panel dropped to replace the headlight switch.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,112
From: Crossville TN
If I were you, I'd set up a hand-held hair dryer so that it would warm-up the speedo head and dry it out. Then, put a dab of clear silicone sealant over that hole.
Drilling that hole might seem like a good idea; but, in reality, that's where the moisture is getting IN, as well. When you heat it, the air inside will heat and the moisture will evaporate (still inside); but the heat will also expand the air and force some of it out. If you can figure out how to use a helium-filled balloon to force helium gas into the head (and expel the air), that might help the fogging problem, too. Again, seal that hole when done. If you seal it while the speedo is warm, then as it cools it will create a slight vacuum in there. That will also assist in reducing the fogging.
Good luck with it....
Drilling that hole might seem like a good idea; but, in reality, that's where the moisture is getting IN, as well. When you heat it, the air inside will heat and the moisture will evaporate (still inside); but the heat will also expand the air and force some of it out. If you can figure out how to use a helium-filled balloon to force helium gas into the head (and expel the air), that might help the fogging problem, too. Again, seal that hole when done. If you seal it while the speedo is warm, then as it cools it will create a slight vacuum in there. That will also assist in reducing the fogging.
Good luck with it....
