Ignition Contact Set Replacement for the 1937-1938 GMC T14B
Keep your classic GMC's inline-six engine running reliably by understanding how to service the ignition points.
- The ignition contact set (points) is a critical maintenance part on the 1937-1938 GMC T14B that wears out over time.
- Common failure symptoms include hard starting, rough running, stalling, and loss of power.
- Always replace the ignition condenser at the same time as the points to prevent premature failure of the new parts.
- Using a quality aftermarket brand like Standard Ignition is important for reliability.
Understanding the Ignition System in Your Vintage GMC
The 1937-1938 GMC T14B was built with a straightforward and durable ignition system designed for reliability. At its heart are the ignition contact set and condenser. Unlike modern cars with computers, your truck's ignition timing is controlled mechanically by these parts. The points are a wear item, meaning the rubbing block that rides on the distributor cam wears down over time, and the electrical contacts can become pitted or burned. This changes the timing of the spark and is why they require periodic replacement to maintain engine performance.
Symptoms of a Failing Ignition Contact Set
When the points in your T14B begin to fail, you will notice clear signs of engine trouble. These symptoms often start gradually and will worsen until the truck no longer runs.
- Difficulty Starting: A very common first sign is an engine that cranks but won't start, or takes a long time to fire up. This is because worn or misaligned points cannot create the clean electrical break needed for a strong spark.
- Engine Misfires and Rough Running: Pitted or burned points cause a weak or inconsistent spark, leading to engine misfires. You'll feel this as a rough or shaky idle, and the engine may stumble or hesitate when you accelerate.
- Engine Stalling: The engine may stall at low speeds, like when you come to a stop. This can happen if the points are not opening and closing reliably at low RPMs.
- Reduced Power: If the spark is weak or timed incorrectly due to worn points, the engine won't burn fuel efficiently, resulting in a noticeable loss of power.
Distributor Shaft Wear
On high-mileage engines, the bushing inside the distributor housing can wear out. This allows the distributor shaft to wobble, which constantly changes the point gap and makes consistent timing impossible, even with new points. If you notice side-to-side play in the shaft, the distributor may need to be rebuilt or replaced for any new ignition parts to work correctly.
Choosing the Right Aftermarket Ignition Contact Set
For a vehicle from the 1930s, new original equipment (OEM) parts are no longer manufactured. All new replacement parts are from the aftermarket. The key is to choose a brand known for quality components.
Standard Ignition (Standard Motor Products): Standard is a long-standing American company that has been making quality ignition parts for decades. Their "Blue Streak" line is often considered a premium-quality option for vintage applications, known for reliability. For a critical component like ignition points, using a reputable brand like Standard Ignition is a sound choice over generic, unbranded parts which may have inconsistent quality.
Always Replace the Condenser
The ignition condenser is a small capacitor that works with the points. Its job is to absorb voltage when the points open, preventing a large arc that would quickly burn and destroy the contact surfaces. A failing condenser will cause a brand-new set of points to fail in a very short time. It is essential to replace the condenser every time you replace the points.
Aftermarket Ignition Contact Set Cost for 1937-1938 GMC T14B
| Part Type | Estimated Cost |
|---|---|
| New Aftermarket (Standard Ignition) | $26.77 - $27.65 |
| Shop Labor | $80 - $150 |
Frequently Asked Questions (FAQ)
What exactly are ignition "points"?
Ignition "points" are the common name for an ignition contact set. They are a mechanical switch with two contacts that are pushed open by a cam on the distributor shaft and closed by a small spring. This opening and closing action triggers the spark from the ignition coil.
How often should I replace the ignition points on my T14B?
For vintage vehicles, ignition points are a regular maintenance item. While modern cars can go 100,000 miles on spark plugs, points often require checking and adjustment every year and replacement every 10,000 to 20,000 miles, depending on use. Given the age of the vehicle, regular inspection is key.
What tools do I need to replace the ignition points?
You will need basic hand tools like a screwdriver and small wrench to access the points inside the distributor. The most important specialty tool is a feeler gauge, which is used to set the gap between the points when they are open. Some mechanics may also use a dwell meter for a more precise final adjustment.
Is Standard Ignition a good brand for my classic GMC?
Yes, Standard Motor Products (SMP) is a well-regarded manufacturer in the aftermarket, especially for ignition components for classic American vehicles. Their parts are known to be a reliable choice compared to lower-quality alternatives.
Technical Specifications
Point Gap: Approximately 0.018" - 0.020" (Consult a service manual for exact specification). Distributor Rotation: Clockwise.
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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.