How to Shim a Starter: A Step-by-Step Video Guide
Starting your car shouldn't be a gamble. A struggling starter motor often points to a simple fix: shimming. This guide provides a comprehensive, step-by-step walkthrough of how to shim a starter, including common questions and troubleshooting advice. While this guide is text-based, the best way to learn this procedure is by watching a video demonstration. Search YouTube for "How to shim a starter" for visual guidance alongside these instructions. Remember, safety first! Always disconnect the battery's negative terminal before beginning any work on your vehicle's electrical system.
Understanding Why Shimming is Necessary
Before diving into the process, it's crucial to understand why you might need to shim your starter. The starter motor engages the flywheel to crank your engine. If there's too much distance between the starter and the flywheel, the starter's pinion gear won't fully mesh, resulting in a slow crank or no crank at all. Shimming reduces this gap, allowing for proper engagement. This issue is often exacerbated by worn engine mounts or general wear and tear.
Tools You'll Need
Before you begin, gather the necessary tools:
- Socket wrench set: You'll need the correct size sockets to remove the starter bolts.
- Ratchet: To turn the sockets.
- Extension: May be needed depending on starter location.
- Shims: These are typically thin metal washers, often made of steel or brass. The correct thickness will depend on your vehicle and the specific gap needed. Often, shims come in sets with varying thicknesses. Never use makeshift shims; always use shims designed for this purpose.
- Jack and jack stands (optional but recommended): For easier access to the starter.
- Wrench for battery terminal: To disconnect the negative terminal.
- Gloves: Protecting your hands is always a good idea.
- Clean rag or shop towel: For cleaning and wiping up any spilled fluids.
Step-by-Step Guide to Shimming a Starter
(Remember to always consult your vehicle's repair manual for specific instructions and torque specifications.)
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Disconnect the battery's negative terminal: This is the most crucial safety step. Failure to do so could result in electrical shock or short circuits.
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Access the starter motor: This varies greatly depending on the vehicle make and model. Often, it's located on the engine block, near the transmission bell housing. You might need to remove other components to gain access. Again, your vehicle's repair manual is your friend here.
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Remove the starter motor: Carefully remove the bolts securing the starter motor. Keep track of the bolts and their locations for reinstallation.
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Measure the gap: With the starter removed, carefully inspect the gap between the starter's pinion gear and the flywheel. This is where experience comes in handy and a visual guide (video) is exceptionally helpful. You might need a feeler gauge to accurately determine the gap.
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Select appropriate shims: Based on your measurement, choose the appropriate shim(s) from your set to reduce the gap. Start with the thinnest shim and re-measure.
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Install shims: Carefully place the shim(s) between the starter motor and the engine block, ensuring proper alignment.
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Reinstall the starter motor: Secure the starter motor back in place using the bolts you removed earlier. Tighten them to the manufacturer's specified torque.
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Reconnect the battery's negative terminal: Once the starter is securely fastened, reconnect the battery terminal.
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Test the starter: Attempt to start your vehicle. If the problem persists, you might need to adjust the shimming further, or there could be a more significant issue.
Troubleshooting and Frequently Asked Questions
How thick of a shim do I need?
The shim thickness depends entirely on the gap between the starter and the flywheel. Start with the thinnest shim and incrementally add thicker ones as needed. Improper shimming can damage the starter or flywheel.
What happens if I shim the starter incorrectly?
Incorrect shimming can lead to stripping the starter gear, damage to the flywheel teeth, and a continued inability to start the car. In worst-case scenarios, it can even cause internal damage to the starter motor itself.
Can I use washers instead of shims?
No. While washers might seem similar, they are not designed for this purpose and may not provide the necessary strength or accuracy. Using unsuitable materials could cause damage. Always use purpose-built shims.
My starter still isn't working after shimming. What should I do?
If the issue persists after shimming, there could be other problems with the starter motor itself, the battery, the ignition system, or even the flywheel. You might need professional assistance from a mechanic to diagnose and repair the underlying problem.
Remember, while shimming a starter is a relatively straightforward repair, it requires careful attention to detail. If you're unsure about any part of the process, seek professional help to avoid causing further damage. A short video demonstration can significantly improve your understanding and make the process easier and safer.
