Reply to "Rust Prevention Inside Sub Structures"

In an old issue of the POCA Newsletter I showed the preferred areas, but basically, we all pick our spots; there is no perfect location. And no- the front subframes seldom cause the problems found at the rear, so they don't usually need drilling.
The lower subframe rails are about 2 feet long on each side. There are numerous doublers and internal/external reinforcements that are visible from below. Divide up the length from the bellhousing to the rear crossmember into 3 rough areas, pick spots that have convenient drill access and try to avoid the doublers as it only makes drilling harder going thru 2 or 3 layers of steel. And don't forget the bottoms of the rear a-arm supports. When drilled, a cascade of talcum-fine red dust will start coming out: this is finely ground rust, dirt and other things best not thought about too much. Some owners fish around with flexible magnets thru the oval top holes in the frames to pull out magnetic debris. Sometimes its possible to fish out sizeable rocks, too. Then they use an air gun to blow as much of the dust out before applying rust preventative.

If you're up on jackstands already, consider also clearing the rocker panel drains. There are several on each side and nearly always there will be one that's smashed flat. The drains should be elongated ovals about an inch long with a dividing panel lengthwise thru the middle. The rockers are made in 3 pieces: inner, outer and a central stiffener panel that's perforated with giant holes. The central stiffener is visible as the divider thru each drain hole. If the central divider is knocked sideways or plugged with paint/undercoating, it actually isolates an area of the rocker panel assembly from draining. With a small screwdriver, pry/bend/tweek the metal so the oval again open on both sides of it's divider.