1. Assessment:
* Extent of Damage: How much of the bolt is sticking out? Is it completely broken off flush with the alternator bracket or is there some protrusion? This determines the best approach.
* Bolt Size: Identify the bolt size and thread pitch. You'll need this for replacement. Take a good bolt to a hardware store for matching or use calipers to measure if you're comfortable.
* Bracket Condition: Inspect the alternator bracket for cracks or damage around the broken bolt hole.
2. Removal Options (depending on bolt condition):
* If some bolt protrudes: Use a pair of pliers (vice grips or locking pliers work well) to grip the broken bolt and turn it counterclockwise. If it's a stubborn, rusted bolt, you might need to use penetrating oil (like PB Blaster) several hours or overnight before attempting to remove it. Apply heat carefully with a propane torch to help loosen the bolt (be careful not to damage surrounding components).
* If the bolt is broken flush: This is trickier. Here are several options:
* Easy-Out: An easy-out (bolt extractor) is a specialized tool designed for removing broken bolts. These are available at most auto parts stores. This is usually the best approach. Follow the instructions carefully, as forcing it can cause further damage.
* Drill and Tap: If the easy-out doesn't work, carefully drill a small pilot hole in the center of the broken bolt. Gradually increase the drill bit size until you've removed most of the broken bolt. Then, use a tap to re-thread the hole to the correct size and thread pitch. This requires precision and the right tools. If you're not experienced with this, take it to a mechanic.
* Weld a Nut: You can carefully weld a nut onto the top of the broken bolt. Let it cool, then use a wrench to unscrew the nut (and broken bolt). This requires a welder and skill. Improper welding can damage the bracket.
3. Replacement:
* Once the broken bolt is removed: Clean the threads in the bracket thoroughly.
* Install new bolt: Install a new bolt of the correct size and thread pitch. Use a torque wrench to tighten it to the manufacturer's specified torque (usually found in a repair manual or online). Don't overtighten.
4. If the Bracket is Damaged:
* If the bracket is cracked or severely damaged, it will need to be repaired or replaced. This might involve welding (if possible) or purchasing a new alternator bracket.
Important Considerations:
* Safety First: Disconnect the battery's negative terminal before starting any work. This will prevent accidental shorts.
* Tools: Gather the necessary tools before you begin. This includes the correct size sockets, wrenches, pliers, penetrating oil, possibly an easy-out, and potentially a drill and tap set.
* Professional Help: If you're not comfortable working on your vehicle, or if the damage is extensive, take your S10 to a qualified mechanic. Improper repair can lead to more serious problems.
Remember to consult a repair manual specific to your 1989 S10 for torque specifications and other important details. This will make the repair much safer and easier.
