runs into the power unit. How do I make the chain stop so the metal unit doesnt run into the power unit and get locked up? I already adjusted the chain but it didnt work.
Hrly's right. However, one more potential problem- If turning the up limit switch doesn't change where it stops, the internal limit switch assembly may be damaged, loose, or may have a corroded contact. Quote frankly, if your unit is more than ten years old, it may be well worth it to replace it.
Genie brand openers have the stop switches at the end of the rail, Craftsman travel limits are internal and adjusted with small flat blade screwdriver. Start by disconnecting the door from the opener and turning the open limit screw several turns to decrease travel. (1 turn = approx 1 travel). Then fine tune. Openers don't normally just start messing up on travel limits, and the fact you say adjusted the chain leads me to suspect you may have an issue with the gear and sprocket assembly. The plastic gear inside may be stripping out or a bushing on this assembly may be going out. You can replace yourself or have a garage door company do it for you. You can get them from any door company, Sears, or on line. Good Luck
I've installed lot of garage door openers, and there's always a switch at each end of the arm that stops the door in both directions. Sounds like you're missing the switch that stops it, or the switch isn't working properly. Refer to your owners manual or call Sears or look for your manual on the internet. If it is missing or not working I believe Sears has repair kits for them. Good luck
