by John Pfanstiehl
Placing chrome on plastic was an inexpensive way for General Motors to dress up parts. Unfortunately, that coating deteriorates over time. Here we’ll show how to replace the astro-ventilation chromed duct balls, the felt seals that hold them snugly, the ball housing and related parts. In addition we’ll show options for the duct balls and vent valve shut-off knobs.
Replacing the astro-ventilation duct balls is fairly straightforward. Plus, it’s clean work – no special tools are required and one side can be replaced at a time.
01: The chrome on the vent duct balls eventually becomes marred with pits and bubbles. Steel wool or chrome polish won’t help make the chrome look good again at this stage.
02: Zip Corvette offers both the original style 1968-1977 Astro-Vent Duct Chrome Ball and distinctive Vintage Air Custom Trident and Penta Aluminum Vent Balls with either a clear anodized or black anodized finish. The Trident and Penta aluminum duct balls are sold separately and are made in the USA.
03: Zip Corvette also offers replacement 1968-1977 Vent Ball Seals and the 1968-1977 Astro-Vent Duct Ball Plastic Retainer. Plus Zip offers a set that includes a pair of the chrome vent balls with felt seals.
04: On the driver’s side we got lucky: the ball just pulled out. Note that the felt seals are accessible when the ball vent is out and they could be replaced easily if the ball was too loose in its socket.
05: Wax the chrome plating on the replacement ball before installation in hopes that it will preserve the finish.
06: The replacement chrome vent ball fits snugly and looks a lot better than the old tarnished part.
07: The passenger’s side vent ball did not pull out easily, therefore the lower dash pad required removal. First, remove the sill plate and then the two screws on the side of the pad. Also remove the radio access side panel (one screw) at the forward end of the shifter console. For step by step instructions on how to remove a sill plate, see Zip’s technical article “1968-1977 Corvette Sill Plate Replacement“.
08: Remove the kick panel by easing its lower edge inward and downward. If it doesn’t slide out, look for the single Phillips screw that originally attached the upper front of the panel. This screw is often left out because it is difficult to start and usually it isn’t necessary.
09: Remove the three black screws at the top of the panel. Look closely because each screw should have a thin cylindrical feral and it often stays in the panel. Remove the two chrome screws that go through the instrument housing and remove the dash pad.
10: Three screws attach the duct valve assembly and the vent ball housing to the rear of the dash pad. Don’t over tighten the screws; the pad material is soft and strips easily. The original #8 screw is at the top but the two lower screws at one time needed to be replaced with larger #10 screws.
11: Zip Corvette also offers a set of six of the original style 1968-1977 Astro-Vent Duct Housing to Dash Mount Screws that attach the duct housing to the dash pad.
12: After the new felt seals are glued into the housing and the vent ball is installed, reinstall the dash pad. The new chrome vent ball looks perfect and is a big improvement to the looks of the interior.
13: Zip Corvette offers two types of vent valve knobs. The black plastic knob is the 1972-1977 Dash Vent Ball Shut-Off Valve Knob while the chrome metal knob is the 1969-1971 Dash Vent Ball Shut-Off Valve Knob. Both are sold in pairs and screw onto the valve shaft. Either will work which enables choosing a subtle look or bling.
1968-1977 Corvette Vent Ball & Seal Replacement
Source: Zip Corvette Corvette Parts
8067 Fast Lane | Mechanicsville, VA 23111 | (800) 962-9632
Corvette Parts List Related to Article:
- 1968-1977 Vent Balls w/Seals (Car Set)
- 1968-1977 Astro-Vent Duct Chrome Ball
- 1968-1977 Vintage Air Custom Trident Aluminum Vent Ball (Clear Anodized)
- 1968-1977 Vintage Air Custom Trident Aluminum Vent Ball (Black Anodized)
- 1968-1977 Vintage Air Custom Penta Aluminum Vent Ball (Clear Anodized)
- 1968-1977 Vintage Air Custom Penta Aluminum Vent Ball (Black Anodized)
- 1968-1977 Astro-Vent Duct Ball Plastic Retainer
- 1968-1977 Vent Ball Seals
- 1968-1977 Astro-Vent Duct Housing to Dash Mount Screws
- 1969-1971 Dash Vent Ball Shut-Off Valve Knobs
- 1972-1977 Dash Vent Ball Shut-Off Valve Knob