An extension spring door is more forgiving to work around than a torsion door, but forgiving isn't the same as safe. The springs sit along the horizontal tracks under tension, and a frayed safety cable on a 1980s-era setup is one of the more common things we find on these calls - it's cheap, it's often overlooked, and it's the part that keeps a broken spring from becoming a projectile. If your garage went up with the house around 1985, check that a cable even runs through the spring; some original installs never had one and are overdue for the fix regardless of what else looks fine. Swapping a roller or tightening track bolts is reasonable weekend work. Touching the spring, the cable, or anything under tension isn't, and we'd rather tell you that up front than let you find out the hard way. If you're not sure which type of spring your door has, that's worth a call before you reach for a wrench.