Hy wiltrek, if your truck has Wagner FR-3 rear brakes, there will be two slots in each backing plate, one on the upper forward side, and one on the rear lower side. Adjust upper forward shoe by inserting the adjustment tool through the backing plate and engaging the adjusting wheel, now move the outbord end of the tool down towards the axle tube to decrease the clearance between the brake shoe and drum, do this until a light drag is felt while turning the drum, then turn the adjusting wheel four clicks in the opposite direction for running clearance. Now proceed to rear lower adjuster, the procedure is the same, hope that helps.
