Diagnostic: inside slide locks do not usually fail because they are so basic it is just a sliding piece of metal usually very thick. Maybe if you have a garage door that has a good amount of rust from living near coastal areas you might have to replace one but I have never seen one fail. And just because I have never seen one fail doesnt mean that they have it
Cost: between $15 to ¬30
Difficulty: easy
Time to repair: 60 minutes or less
Tools needed: 3⁄8 or 7/16 wrench or socket, 1⁄8 inch drill bit an impact drill if you have one but youll mostly need a drill to pre drill some holes.
Hammer, pencil or marker.

Inside slide locks are mostly use and garage doors that do not have a automatic opener installed. If you do have a automatic garage door opener and you probably do not want or need the slide lock I dont know how many times somebody has locked the garage door and forgot to slide lock back before they operate the opener and this totally can ruin your top section of the garage door. You can most likely find a slide lock for your garage door on the internet and im pretty sure they sell them at lowes and home depot where you would find your garage door section that has hinges and rollers and remotes for your openers im pretty sure they sell them I think ive seen them there before. . They usually come in different sizes but theyre all basically the same so do not think you need a certain size slide lock because they all work exactly the same it just depends on the manufacture. If you are putting a slide lock on a steel constructed garage door it may help to also get some self tapping metal screws. This is only useful if you are using an impact drill you might get away with using a standard drill you will just have to tested out and see. . If you are installing your slide lock on a door constructed of wood then you will need to find some wood screws that are less than 1 1/2 inches because that is the average thickness of a wood garage door panel. You will want a pretty hefty screw but just no bigger than an inch and a quarter. Try not to use household wood screws that are skinny and small because they can tear away from the garage door pretty easily.

Step 1
First thing you have to do is find the correct spot on your track for the slide lock to slide into. If you are replacing an older slide lock with a new one then you can skip this step.
Some manufacturers will already punch out these holes on the vertical track sometimes you will see up to five different slots and then on the other hand some manufacturers will stamp the rectangle or hole but not remove the center. You can identify these by looking for the rectangular shaped stamp in the vertical track the way to remove the center is to pop out that center of the rectangle it is easier to tap it out with a chisel on the left and right hand side of the rectangle. Dont be afraid to tap hard enough sometimes they can be difficult to get out but do not bend the track. Once you have removed this small piece of metal from the track you can now move on to step once you have removed this small piece of metal from the track you can now move on to step two 2.

Step 2
Now you have to position the actual lock on the right or left hand side of the door where you have made the slot inside the track for the slide part of the lock to slide through. The first thing you have to remember when positioning your lock is the left and right placement in other words you dont want the lock to be too far to the right because when it is unlocked and pulled to open the door sometimes when the door is going up if it is too far to the right it will catch in the track and keep for the door from opening. You will notice on the slide part of the lock that slides through the track is there is a hole in it this is for a padlock so you can actually lock your door down from the inside as well as the outside. So when you are positioning your lock left and right just slide it through the track just enough to access that padlock hole any further than that it may cause a problem. Now to properly adjust the up and down position you want to make sure the slide part of the lock is not too close to the top of the whole or the bottom now that you have the Right up¬and¬down and left and right position where you want to lock to slide into the whole take a pencil or marker and mark in the mounting holes on top and bottom where you want to put the screws. Remove the lock from the door and pre¬drill your screw holes with the drill bit then you will put the lock back on the door make sure the position is correct and screw it down to the metal or wood door. Once this is done you want to slide the lock back to unlock and open the garage door and make sure that the lock does not catch on the track when it goes all the way up if it does catch on the track then you will need to move it over a little bit you should be able to see how much you need to move it by looking at it hit the track when it goes up. No grab a padlock and make sure that you can get it through the small hole when the door is locked if it works fine then youre good youre all done. Pad locking this type of lock obviously locks your door from the outside as well as from the inside this can help keep somebody from going into your garage and open your garage door in stealing your car or anything else in the garage they can only go out through the garage.