Distributor Cap Guide for the 1968-1969 International 908C
Solve common running issues on your classic International by learning to spot and replace a bad distributor cap.
- A failing distributor cap is a common cause of misfires, hard starting, and rough idling on the 908C.
- Visually inspect your current cap for cracks, corrosion, and carbon tracks before ordering a new one.
- Always replace the distributor rotor at the same time as the cap for a complete tune-up.
- Verify your distributor type (e.g., Prestolite, Delco-Remy) before purchasing, as caps are not interchangeable.
Is Your International 908C Running Rough? It Could Be the Distributor Cap
The distributor cap on a classic truck like the 1968-1969 International 908C is a normal wear-and-tear item. Over time, the high voltage passing through it can cause cracks, corrosion on the metal contacts, and carbon buildup. When this happens, the powerful spark your engine needs to run properly becomes weak or inconsistent, leading to several noticeable problems. Since your truck doesn't have a modern check engine light, you need to pay attention to how the engine runs to spot a failing cap.
Symptoms of a Failing Distributor Cap
A bad distributor cap is a common tune-up part that can cause clear issues. Look for these signs:
- Engine Misfires: The engine sputters, shakes, or feels weak, especially when you accelerate or go up a hill. This happens when a spark doesn't reach a cylinder correctly.
- Hard Starting: The truck cranks for a long time before the engine starts, or it might not start at all. This can be worse on damp or cold mornings when moisture gets into a cracked cap.
- Rough Idle: When your truck is stopped, the engine runs unevenly or shakes.
- Stalling or Backfiring: The engine may shut off unexpectedly while driving or idling.
- Visible Damage: The best way to check is to look. Pop the clips or screws off your distributor and inspect the cap. Look for cracks in the plastic, white or greenish corrosion on the metal terminals, or thin black lines that look like pencil marks between the terminals (called carbon tracking). Any of these signs mean it's time for a new cap.
Critical Check Before You Buy
International Harvester sometimes used distributors from different suppliers (like Prestolite or Delco-Remy) in the same model year. These different distributors use caps that are NOT interchangeable. Before ordering, remove your old cap and check if its terminals are male (posts) or female (sockets) to ensure you buy the correct replacement.
Choosing the Right Aftermarket Cap
For a vehicle from the late 1960s, finding a "New Old Stock" (NOS) OEM International Harvester part is nearly impossible and not necessary. Today's top aftermarket brands often meet or exceed the original quality standards. The main difference between them is often the material used for the electrical contacts inside the cap.
| Brand Tier | Available Brands | Quality & Materials | Price Range |
|---|---|---|---|
| Premium Aftermarket | Standard Ignition (Blue Streak) | Often considered a top-tier choice by professionals for ignition parts. Their premium lines typically use solid brass terminals, which offer the best conductivity and corrosion resistance for long-term reliability. | $35 - $52 |
| Standard Aftermarket | Standard Ignition, Walker Products | These are reliable brands that produce quality replacement parts designed to fit and function like the original. They may use aluminum or brass terminals depending on the specific part line. A cap from these brands is a solid choice for daily driving and regular use. | $19 - $35 |
Pro Tip: Always replace the distributor rotor at the same time you replace the cap. They wear out at a similar rate, and it's a cheap and easy way to ensure a complete ignition tune-up.
Frequently Asked Questions (FAQ)
How often should I replace my 908C's distributor cap?
Distributor caps are a maintenance item. It's good practice to inspect it annually and plan on replacing it as part of a tune-up every 20,000 to 30,000 miles, or whenever you replace spark plugs and wires.
Should I get a cap with brass or aluminum contacts?
Many classic truck enthusiasts prefer caps with brass terminals over the standard aluminum ones. Brass is a better electrical conductor and is more resistant to corrosion, which can lead to a longer service life and more consistent performance.
Is replacing a distributor cap a good DIY job?
Yes, this is one of the easiest tune-up jobs on a classic truck. It typically requires only basic hand tools like a screwdriver or nut driver. The key is to transfer the spark plug wires from the old cap to the new cap one at a time to make sure the firing order stays correct.
What other parts should I inspect when replacing the cap?
Always replace the distributor rotor with the cap. It's also a good time to inspect the spark plug wires for cracks or brittleness, check the points and condenser (if not converted to electronic ignition), and look for any oil leaks inside the distributor.
Technical Specifications
The 1968-1969 International 908C was available with V8 engines, including the 266, 304, and potentially others. It used a conventional ignition system with a distributor. Caps could be from different manufacturers like Prestolite or Delco-Remy and feature either male (post) or female (socket) terminals. High-quality aftermarket caps feature brass terminals for better conductivity and corrosion resistance.
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.