Before You Start:
* Gather Tools: Beyond standard socket sets, wrenches, and a ratchet, you'll need a starter removal tool (makes it much easier than wrestling with it), a torque wrench, and a variety of shims (typically various thicknesses of metal washers). Have a helper if possible, as the starter can be heavy and awkward.
* Consult a Repair Manual: A factory service manual or a reputable repair manual specific to your year and model Blazer is invaluable. It will show you the exact location of the starter, bolt sizes, torque specs, and the proper shimming procedure. This is crucial for avoiding damage.
* Note Existing Shims: Before removing the old starter, carefully count and measure the thickness of any existing shims. Take photos, too. This is your baseline for comparison.
* Clean the Area: Clean the area around the starter thoroughly to remove dirt and debris. This will help you see clearly and avoid dropping small parts.
* Disconnect the Battery: This is the most important safety step. Disconnect the negative (-) terminal first.
Removing the Old Starter:
* Access: Access to the starter on a Blazer can be tight. You might need to remove some surrounding components for better access. Your repair manual will guide you.
* Starter Removal Tool: Use a starter removal tool to make the process easier and avoid damaging the starter or surrounding parts.
* Wiring: Carefully disconnect the battery cables and any other wiring connected to the starter. Label the wires if necessary to avoid confusion during reinstallation.
Installing the New Starter:
* Positioning: Carefully position the new starter in place. Ensure it aligns correctly with the mounting holes.
* Bolts: Tighten the bolts just enough to hold the starter in place. Do NOT fully tighten yet.
* Shimming: This is the critical part. Start by installing the same number and thickness of shims that you removed from the old starter.
* Meshing: The starter needs to mesh correctly with the flywheel teeth. This is where you'll need to check for proper engagement. This is typically done using a pry bar or screwdriver.
The Shimming Process:
This is iterative. You'll need to go through a process of adjustment:
1. Test Engagement: Attempt to turn the engine over with the ignition. If the starter spins freely and doesn't engage the flywheel, it needs more shims (to move the starter gear closer to the flywheel). If the starter engages too tightly (binding or grinding), it needs fewer shims (to move the starter gear slightly away from the flywheel).
2. Adjust: Remove or add shims (one at a time) as needed. Remember, even a small change in shim thickness can make a difference.
3. Repeat: Test the engagement again after each shim adjustment. This is a back-and-forth process until you find the "sweet spot" where the starter engages smoothly and firmly. The goal is minimal rotational resistance.
4. Torque Specs: Once you achieve proper engagement, and ONLY then, tighten the starter mounting bolts to the torque specifications outlined in your repair manual.
Troubleshooting:
* Grinding: Grinding indicates the starter gear is not meshing correctly with the flywheel. Add or remove shims accordingly.
* Slow Cranking: This might indicate a low battery charge, a faulty battery connection, or other electrical issues. Don't assume it's only the shimming.
* No Cranking: Check all your electrical connections and make sure everything is properly grounded.
Important Notes:
* Patience: Shimming is a trial-and-error process that requires patience and attention to detail. Don't rush it.
* Safety: Always disconnect the negative battery cable before working on the starter.
* Professional Help: If you're not comfortable with this process, consider seeking professional help from a mechanic. A wrong shim can cause considerable damage.
By following these tips and referring to your repair manual, you should be able to replace your starter successfully. Good luck!
