Step 1
Measure the tractor's width at the outside of the rear fenders to determine the necessary width of the cab you will be constructing. Next, measure from the Sears tractor's rear hitch forward to 3 inches ahead of the steering wheel. This will give you the necessary length for the cab. Finally, sit on the tractor's seat and measure from the rear hitch to just above your head. This will give you the necessary height dimension you will need.
Step 2
Cut the wood that will make up the framework of the cab, starting with the pieces that will make up the width of the cab. The best place to mount the back part of the structure of the cab on a Sears tractor is on the trailer hitch, then attach the front of the cab to the tractor's hood. Measure and cut four pieces of 2-by-4 lumber to the width you determined that the cab should be.
Step 3
Measure and cut two pieces of 2-by-4 lumber to the height you measured from the trailer hitch to just above your head. These pieces will fit together with the boards cut to the width of the tractor's cab to form the rear frame of the cab.
Step 4
Construct the rear frame of the cab as a rectangle, securing the lumber together with wood screws, and then drill a single bolt hole into the bottom board so that you can bolt the frame to the trailer hitch mount.
Step 5
Construct a second frame similar to the first that is as wide as the first frame but is measured to the length that you measured from the trailer hitch to just ahead of the steering wheel. For this frame piece, attach the piece of plywood to serve as the roof, securing it with wood screws. If necessary, trim the edges of the plywood to fit using a jigsaw.
Step 6
Construct the windshield frame by using the width measurement as well as the height measurement from the top of the tractor's hood to the overall height measurement you found earlier. Construct this frame the same way that you constructed the first frame.
Step 7
Lay a piece of Plexiglas over the windshield frame and cut it with the jigsaw to the size needed. Next, pre-drill holes around the perimeter of the Plexiglas so that you can screw it in place. When the holes are drilled, use wood screws to secure the Plexiglas to the frame of the windshield.
Step 8
Mount the rear frame to the trailer hitch, and then attach the roof frame and windshield frame together using wood screws. With this installed, measure and cut to fit a piece of Plexiglas for the back of the cab, and then fit it in place with wood screws the same way that you did the windshield frame. When it is in place, drill several 1/2-inch holes in the Plexiglas near the top of the frame to allow fresh air to enter the cab area.
Step 9
Drill a hole through the center bottom lumber of the windshield frame and through the hood of the tractor. Insert a screw up through the hole and secure it in place with a wing nut so that it can be easily removed if you need to service the engine.
Step 10
Mount the hinges to the windshield frame on both sides of the tractor so that the Plexiglas windows will swing open like car doors. One hinge should be at the top of the frame and one at the bottom. Attach a hook latch to the inside of the rear frame on each side so that you can latch the Plexiglas doors closed.
Step 11
Mount the remaining Plexiglas to the hinges with bolts and nuts, and then trim the Plexiglas with a jig saw to fit like a door. Attach the eye for the latch hook to the Plexiglas door by drilling through the Plexiglas and then securing the threaded end of the eye hook to the door with a nut to complete the installation of the cab onto the tractor.