The trunk floor in our Valiant...
The trunk floor in our Valiant was in need of a large piece of repair metal. Since we were going to replace it anyway, we called Year One to get one with the correct bends and dimples.
Before you do any cutting,...
Before you do any cutting, remove the gas tank. Early A-Bodies used a single strap from framerail to framerail to hold it in place. Simply unhook the hose to the fuel pump and the fuel-gauge wire, and then loosen the stud holding the strap. Oh yeah, it's easier if you empty the gas tank before removal. Before you start cutting out the floorpan, make sure all wires (like those to the taillights) are moved so they don't get damaged.
The trunk latch is spot-welded...
The trunk latch is spot-welded to the trunk floor and needs to be moved out of the way. To do this, drill the spot-welds at the bottom of the latch, and lift the trunk latch out of the way just enough to get to the floor. To avoid compromising alignment, we didn't remove the spot-welds at the top.
As gearheads, we take mechanical upgrades and repairs for granted. But, throw in some bodywork and a lot of guys freak out! Replacing sheetmetal is generally a job performed at professional shops. Metal replacement, however, does not have to be feared. If you take your time, cut twice and measure once--or vice versa--it's really not that hard.
The trunk pans in our Valiant could best be described as peppered. If we lived in the Northeast, during the winter we could have filled the trunk with salt and evenly covered the icy highways. We were fortunate that the trunk extension panels--the sheetmetal that extends from the trunk floor to the bottom edge of the quarter-panels--were in good shape. This made the repair easy, because the metal we needed to replace was basically a flat piece of tin.
There are literally hundreds of places to buy sheetmetal, but this time we contacted Year One for the necessary trunk floor, gasket, and trunk mat. Trunk pans can be ordered in separate halves or as one piece. When these cars were originally built, the trunk floors were installed before the quarter-panels were hung. In some cars, it's impossible to fit a one-piece floor into place through the trunk-lid opening. If you do not have the quarters removed, or your car's trunk-lid opening isn't large enough to accommodate a one-piece floorpan, you may want to get the two-piece trunk floor to ease installation. Our Valiant has a large trunk-lid opening, so we opted to replace the entire floor with the one-piece pan, PN M216. If you're planning such a replacement, take your time, and hopefully you'll gain confidence when you see how easy it is.
Here is the opening where...
Here is the opening where the floor was removed. (A) This area of the trunk floor is an overlap weld. Drill the spot-welds out and leave the portion underneath. (B) Also, spot-welds hold the trunk floor to the framerails. Drill the spot-welds out. (C) Where the floor meets the trunk extensions, cut the floor about 1/2 inch in (on the trunk-floor side) from the seam. When the old floor is gone, the remaining piece of the floor can be removed with a grinder or cut-off wheel from the extension. Finish cutting the floor loose at the rear portion and take it out. Section D was rusted out, and since no repair panels are available for this area, a new piece of sheetmetal will be added.
Here, you can see the excess...
Here, you can see the excess trunk-floor metal has been removed from the extensions, and the spot-welds on the frame have been ground smooth. After the floor was removed and everything cleaned up, we coated the inside of the framerails with a rust inhibitor.
With the opening ready for...
With the opening ready for the new sheetmetal, we put the new trunk floor in place and sprayed primer along the bottom of the pan at the framerails. This will show us where to drill the holes for the spot-welds.
Here, you can see the placement...
Here, you can see the placement of the holes for the floor-to-frame filler-welds. Originally, the factory had a welder with long arms that would pinch and weld the two pieces together. Most enthusiasts don't have access to this type of tool, so the floor is drilled and the metal welded to the frame by filling the holes.
The first welds you need to...
The first welds you need to make are the filler-welds to the framerails. After that is done, weld the back of the pan to the taillight-panel area. Weld in short, 1- to 2-inch lengths, and alternate locations to avoid heat-warping the metal.
Remember the spot-welds you...
Remember the spot-welds you drilled from the latch? Push the latch down in place and fill the drilled holes. Make sure the latch is not twisted or off-center before you reweld it. Next, weld the overlap seam at the front.
Underneath, the floor is clamped...
Underneath, the floor is clamped to the extension and welded. From the factory, these were also pinch-welded. We simply spot-migged every inch or so.
We put our fuel tank in place...
We put our fuel tank in place and marked the general location at which the filler neck will be. We then removed the gas tank and drilled small reference holes from the bottom. We placed the new gasket on the top side of the floor, centered it over the drilled reference holes, traced the gasket, and cut the necessary opening. Remember to cut the opening smaller than the gasket so it can be attached to the floor when you're done. Reattach the fuel tank, and slide the filler neck through the gasket and into the tank.
Finally, replace the fuel...
Finally, replace the fuel line and gauge wire to the tank.
After you paint the new sheetmetal,...
After you paint the new sheetmetal, finish it off with a new trunk mat. Now you can keep your junk in your trunk.