Lubricating hinges, tightening visible bolts, and clearing the track of debris are reasonable DIY tasks on a door this age, and they're worth doing regularly given how much of the original hardware is likely still in place. What isn't reasonable is touching the torsion spring. A spring under tension on a door built in 1976 has had forty-plus years to lose some of its rated strength unevenly, and releasing or adjusting it without the right bars and clamps is how people get hurt, not inconvenienced. If the door is off its track, if a cable has slipped the drum, or if the opener is pulling against resistance it shouldn't be fighting, stop and call rather than force it. We'll also say plainly: if you're not sure whether what you're looking at is the spring, don't guess by testing it yourself. That one judgment call is the difference between a repair and an ER visit.