If the glovebox door on every '78-'82 Corvette you've seen is loose, don't fear-every '78-'82 that comes to my shop has a loose glovebox door latch.
The glovebox-door-latch assembly nut is behind the lock-cylinder-knob assembly. The difficult part of the repair is removing the lock-cylinder-knob assembly.
With the glovebox door open, the latch lever must be pushed into the latched position. To accomplish that, locate the small square window on the right side of the latch assembly. There is a tab in the square window that must be pushed inward. Once the tab is pushed in, the lock-cylinder assembly can be removed by pulling outward. Sometimes, the lock-cylinder assembly becomes stuck because it hasn't been lubricated, but inserting the key into it assists in removing the lock-cylinder knob. The assembly must be started out of the latch assembly before inserting the key.
Even from the factory, glovebox-door fitment was sometimes atrocious, but the door can be adjusted up and down slightly by loosening the four 7mm screws that hold the hinges to the dash. Unfortunately, the screws are difficult to access and do not allow a major change of position.
This is the opening that allows...
This is the opening that allows removal of the lock-cylinder knob. Once the lock lever is placed in the latched position, push the tab in the opening inward. Pull outward on the lock-cylinder knob while keeping the tab pushed inward.
A pair of channel-lock pliers works well when adjusting the hinges. With the glovebox door open, squeeze the hinge together to lower the door. Conversely, spread the hinge to raise the door.
If the glovebox door on your shark is recessed too deep in the dash, raise the door to the almost-closed position and pull out slightly by hand. If it is not flush with the dash and protrudes, use the same procedure but push it in slightly.
If the door is in or out at one corner only, grasp it and twist it slightly. Once it fits properly, tighten the four 7mm screws that retain the outer glovebox door to the inner glovebox door. Take care when making these adjustments, as a small amount of force is all you need to change the position.
If you decide to remove the glovebox door, note the following steps. The glovebox inner liner must be removed. Follow that by removing the outer Phillips head screws that hold the dash assembly to the door pillar. Next, locate the passenger-side A/C duct below the glovebox opening. The A/C duct pushes onto the outer A/C vent register. Pull outward on the A/C duct, moving it off the A/C register toward the firewall. Then, pull the other end of the A/C duct off of the plenum. Now the screws that retain the glovebox's outer hinge can be removed.
The inner-hinge screws can be removed, but the dash must be pulled outward to allow removal of the screw. I replaced the dash assembly, so I had to install the original glovebox door on the new dash assembly. That's why I decided to refinish all the glovebox pieces.
 The glovebox lock assembly...  The glovebox lock assembly is removed from the door. Note the lock lever is in the latched position for removal of the lock-cylinder knob. The retainer nut is on the left side of the lock-cylinder-knob assembly. |  Tightening the nut with a...  Tightening the nut with a pair of large external snap-ring pliers works well. The internal portion of the nut has eight sides, which is necessary for lock-cylinder clearance. |  Lubricate the lock assembly...  Lubricate the lock assembly with Lock Ease before installing. Lock Ease frees up sticky tumblers and lasts many years. The lock assembly should be set aside overnight to allow the lubricant to drain. The lubricant has a tendency to keep flowing for a while, and can stain if not cleaned within a few hours. |
To properly refinish the inside portion of the glovebox door, begin with a light sanding with 320-grit sandpaper. Follow by wiping the door with Xylene thinner before painting. With a couple coats of Krylon semiflat black paint, the inside of the glovebox door will look like new.
Here, the glovebox is ready...
Here, the glovebox is ready for installation after refinishing. Note the hinge assemblies with two screw holes each. The curved portion of the hinge above the hinge retainer plates is where door alignment can be accomplished.
In the past, I would have bead-blasted the inner part of the glovebox door before repainting. But, if the factory paint is still in good shape and no corrosion is present, a light sanding is all that's necessary. Removing all the paint requires metal prepping and priming to ensure adequate corrosion protection. If the factory coat is corrosion free, you can be assured it will give protection with a good coat of paint.
The outer portion of the glovebox door requires a thorough cleaning before refinishing. Use car-wash soap to remove any grease or dirt. Then, wipe down the surface with Xylene to remove any vinyl-protectant residue that may remain. Multiple cleanings are a good idea.
You have two choices for refinishing supplies. Mid America Designs has an interior vinyl dye available in spray cans and quart cans. The spray works well if you're doing just a few pieces. When doing an entire interior, I prefer to use the quart cans of vinyl dye so there won't be a color-match issue. It isn't a good idea to refinish with vinyl dye in high-humidity conditions because it will become cloudy. Put a few coats of clear vinyl dye over the color coat to prevent color-coat wear. Clear vinyl dye can be purchased in matte or glossy finishes.