A Studebaker Owner's Guide to the 1959-1966 Commander Distributor Cap
Keep your classic Commander running smoothly by understanding how to choose and replace your distributor cap.
- For 1965-66 models, you must identify if you have the Studebaker V8 or the GM-sourced engine, as they use different caps.
- Always replace the distributor rotor at the same time as the cap for a complete tune-up.
- Transfer spark plug wires from the old cap to the new one, one at a time, to avoid mixing up the firing order.
- Visually inspect the cap for cracks, moisture, and terminal corrosion as part of your regular maintenance.
Signs of a Failing Distributor Cap
A distributor cap is a wear-and-tear item that operates in a high-voltage, high-heat environment. Over time, the plastic can crack, and the metal terminals inside can corrode or wear down from the constant electrical arcing. When your Commander's distributor cap starts to fail, you'll notice clear signs of engine trouble.
- Engine Misfires or Rough Idle: This is the most common symptom. Worn terminals or cracks in the cap can cause a weak or misdirected spark, leading to an engine that shakes, stumbles, or runs poorly.
- Trouble Starting: A failing cap can make it difficult to start your engine, or even prevent it from starting at all. You might hear the engine crank but fail to turn over.
- Stalling or Backfiring: If the cap is severely cracked or damaged, it can cause the engine to lose power and stall, sometimes with a backfire from the exhaust.
- Squealing or Clicking Noises: Unusual sounds from the engine bay can sometimes be traced back to a distributor issue. A visual inspection is the best way to confirm the problem.
Check for Cracks and Corrosion
The easiest way to check your distributor cap is to remove it and look. Inspect for small cracks, especially around the mounting points. Check the metal terminals on the inside for white or greenish corrosion, or for signs of burning or wear. Also, check the center carbon button to ensure it is present and springy.
Choosing the Right Aftermarket Cap
For a vintage vehicle like the 1959-1966 Studebaker Commander, finding New Old Stock (NOS) or OEM parts is very difficult and often expensive. Aftermarket parts are the most practical and widely available choice. Modern manufacturing can often produce a cap from higher-quality materials than what was available 60 years ago.
A Critical Note for 1965-1966 Owners
For the 1965 and 1966 model years, Studebaker sourced its engines from General Motors. These cars came with Chevrolet-designed 6-cylinder or 283 V8 engines. It is essential to correctly identify your engine before ordering, as the distributor cap for a GM-sourced engine is different from the one used on a Studebaker-built V8.
When looking at brands like Standard Ignition and Walker Products, quality is generally reliable for these applications. Both brands produce parts designed to meet or exceed original specifications. Look for caps made from high-dielectric strength plastic (resists electrical arcing) and that feature brass terminals instead of aluminum. Brass is a better conductor and is more resistant to corrosion, which can lead to a longer service life and more consistent performance.
Typical Replacement Costs
Replacing a distributor cap is an affordable and straightforward job. The parts are not expensive, and the labor involved is minimal.
| Part Type | Price Range |
|---|---|
| New Aftermarket Distributor Cap | $18.86 - $34.65 |
| Shop Labor | $40 - $70 |
Prices are estimates and may vary based on location and supplier. It is highly recommended to replace the distributor rotor at the same time as the cap.
Frequently Asked Questions
How often should I replace my Commander's distributor cap?
Distributor caps are considered a regular maintenance item. For a classic car that may not be driven daily, a good rule of thumb is to inspect it annually and replace it with every major tune-up, or every 2-3 years, regardless of mileage. Also, always replace the rotor when you replace the cap.
Can a bad distributor cap cause a no-start?
Yes, absolutely. If the cap is cracked, full of moisture, or the terminals are completely corroded, it can prevent spark from reaching the spark plugs, resulting in an engine that cranks but will not start.
What is the most common mistake when replacing a distributor cap?
The most common and critical mistake is mixing up the spark plug wires. The wires must be transferred from the old cap to the new cap in the exact same positions to maintain the correct engine firing order. The best method is to move the wires one at a time.
Is it hard to replace the distributor cap myself?
No, this is a great DIY job for a beginner. It typically only requires a screwdriver or a small wrench. The distributor is usually easy to access on these older engines. The entire process should take less than an hour.
Technical Specifications
Fitment varies between Studebaker V8 engines and the GM-sourced Chevrolet engines used in 1965-1966 models. Ensure you select the cap that matches your specific engine. Caps are typically secured with either clips or screws.
We Have This Part in Stock
The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.