Finding the right shim for your 350 Chevy starter can be a frustrating experience, leading to a no-start condition that leaves you stranded. This comprehensive guide will walk you through understanding why shimming is necessary, how to identify the correct shim, and troubleshoot common problems. We'll cover everything from basic principles to advanced techniques, ensuring you get your classic Chevy roaring back to life.
Understanding the Need for Shimming
The starter motor on your 350 Chevy needs to engage perfectly with the flywheel teeth for a reliable start. If the starter isn't properly aligned, it can result in several issues:
- Grinding Noise: A common symptom of misalignment, this indicates the starter gear is hitting the flywheel teeth at an incorrect angle.
- No Start Condition: Severe misalignment can prevent the starter gear from engaging altogether, leaving you with a frustrating no-start situation.
- Premature Starter Wear: Improper alignment puts undue stress on the starter motor components, leading to premature wear and potential failure.
Shimming the starter provides the necessary adjustment to correct this misalignment. The thickness of the shim determines the precise adjustment needed to achieve perfect engagement.
Identifying the Correct Shim
There's no one-size-fits-all solution when it comes to shimming your 350 Chevy starter. The necessary shim thickness depends on several factors, including:
- Starter Model: Different starter models may require different shims. Refer to your starter's specifications or consult a parts professional for guidance.
- Engine Block Condition: Wear and tear on the engine block can affect starter alignment. Accurate measurement is key to determining the correct shim thickness.
- Flywheel Condition: The condition of your flywheel's teeth also influences the necessary shim.
How to Measure for the Correct Shim:
Accurately measuring the gap between the starter and flywheel is crucial. This typically involves:
- Removing the Starter: Carefully remove the starter motor from your 350 Chevy engine, following proper safety precautions.
- Measuring the Gap: With the starter removed, carefully measure the distance between the starter's nose and the flywheel.
- Shim Selection: Based on your measurements and the starter's specifications, choose the appropriate shim thickness. These are typically available in various thicknesses, often measured in thousandths of an inch.
Installing the Shim
Once you've identified the correct shim, installation is relatively straightforward:
- Clean Mounting Surfaces: Ensure both the starter and its mounting surfaces are clean and free from debris.
- Shim Placement: Carefully place the shim between the starter and the engine block.
- Starter Installation: Reinstall the starter, following the manufacturer's instructions.
- Testing: Attempt to start your engine to verify proper engagement. You should hear a clean, consistent engagement without any grinding.
Troubleshooting Common Problems
Even with careful measurement and installation, you may encounter issues. Here are some common problems and solutions:
- Continued Grinding: If grinding persists, double-check your shim thickness. You may need a thicker or thinner shim. Re-measure carefully.
- No Engagement: If the starter still doesn't engage, ensure the starter's solenoid is functioning correctly and that the battery has sufficient power.
- Starter Bolts Stripped: If you have stripped starter bolts, you will need to repair or replace them. This may require additional expertise or professional assistance.
Conclusion
Shimming a 350 Chevy starter might seem daunting, but by understanding the underlying principles, accurately measuring for the correct shim, and carefully following the installation process, you can restore your engine to proper working order. Remember, accuracy is key, so take your time and carefully follow each step. If you're unsure about any aspect of the process, it's always best to consult a qualified mechanic.
