Chrysler Imperial Engine Timing Set Replacement Guide (1966-1976)
Address the weak point in your Imperial's 440 V8 before it becomes a major problem.
- The original nylon-toothed camshaft gear is a known failure point and should be replaced with an all-metal aftermarket set.
- Always replace the timing chain and both sprockets as a matched set.
- A double roller timing set is a highly recommended upgrade for improved durability and longevity, even on a stock engine.
- Choose a quality brand like Cloyes, Melling, or Edelbrock for a reliable repair.
The Achilles' Heel of the Chrysler 440 V8
If you own a 1966-1976 Chrysler Imperial, you have a robust 440 cubic-inch engine. However, it has a well-known weak point: the original camshaft timing gear. To make the engine quieter, Chrysler used a gear made of aluminum with nylon-coated teeth. Over decades of heat cycles and oil exposure, this nylon becomes brittle, cracks, and breaks off. These plastic pieces fall into the oil pan, where they can be sucked into the oil pump pickup screen, blocking oil flow and potentially causing catastrophic engine failure from oil starvation. For this reason, if your engine still has the original nylon-toothed gear, it should be replaced immediately, even if it isn't showing symptoms.
Symptoms of a Failing Timing Set
Before a complete failure, a worn timing set will usually provide warning signs:
- Engine Rattle: A rattling or scraping noise from the front of the engine, especially at idle, is a classic sign of a loose timing chain slapping against the timing cover.
- Poor Engine Performance: As the chain stretches, camshaft timing becomes retarded. This can lead to a loss of power, reduced fuel economy, and sluggish acceleration.
- Timing Issues: When checking ignition timing with a timing light, a mark that jumps around erratically instead of staying steady indicates a sloppy timing chain.
- Engine Misfires or Backfiring: If the chain stretches enough to jump a tooth on the gears, the valve timing will be significantly off, causing misfires, backfiring through the carburetor, or a rough idle.
- No-Start Condition: If the chain breaks or jumps multiple teeth, the engine will not start.
Warning: Plastic in Your Oil Pan
If you find small, brittle pieces of plastic in your oil during an oil change, it is a definitive sign that your original cam gear is disintegrating. Replacement should be considered urgent to avoid oil pump blockage.
Choosing the Right Aftermarket Timing Set
For this vehicle, aftermarket timing sets are a significant upgrade over the original design. You will not find a new OEM part, and you wouldn't want one anyway due to the nylon gear issue. Your main choice will be between a standard "silent" chain set and a double roller set.
Brand Tiers & Recommendations
- Standard Replacement (Good): Brands like Melling and Cloyes offer excellent OE-style replacement sets. These feature all-metal gears, eliminating the nylon tooth problem, and a durable "silent" style chain similar to the original but much more reliable. This is a great choice for a stock, daily-driven vehicle.
- Heavy-Duty (Better): A double roller timing set from Melling Select Performance or Cloyes is a popular upgrade for durability. A double roller chain is stronger and less prone to stretching than a silent chain. While some consider it overkill for a stock engine, it provides peace of mind and is a "fit-and-forget" solution.
- Performance (Best for Modified Engines): For modified engines, a high-quality double roller set from Edelbrock, Melling Select Performance, or Cloyes is the best choice. These are built to handle the stresses of higher RPMs and increased valve spring pressures.
Pro Tip: Single Bolt vs. Three Bolt
The stock 440 engines in this era typically use a camshaft with a single bolt to hold the gear. When ordering your timing set, ensure you select a "single bolt" kit to match your camshaft.
| Part Type | Price Range |
|---|---|
| New Aftermarket (Silent Chain) | $43.13 - $80.00 |
| New Aftermarket (Double Roller) | $80.00 - $185.85 |
| Shop Labor | $400 - $800 |
Frequently Asked Questions (FAQ)
Do I really need to replace my timing set if the engine runs fine?
If the engine has its original nylon-toothed cam gear, yes. The failure of this part is related to the age and degradation of the plastic, not just mileage. It can fail without warning, leading to major engine damage. It's a critical preventative maintenance item for any 1966-1976 Imperial.
Should I get a double roller chain for my stock engine?
A double roller chain is a worthwhile upgrade for any engine. It offers superior strength and resistance to stretching, ensuring your timing stays accurate for longer. While a quality silent chain set is adequate, the extra cost for a double roller is often minimal and provides long-term durability.
Should I replace just the chain?
No. Always replace the timing chain and both gears (camshaft and crankshaft) as a complete set. A new chain on worn gears will wear out very quickly, and worn gears will not mesh properly with a new chain. Timing sets are sold as a matched kit for this reason.
Is replacing the timing set a DIY job?
For an experienced home mechanic, it is a feasible but involved job. It requires draining the coolant, removing the radiator, belts, pulleys, water pump, harmonic balancer, and timing cover. If you are not comfortable with this level of disassembly, it is best left to a professional shop.
Technical Specifications
The 1966-1976 Chrysler Imperial with a 440 V8 engine typically uses a timing set with a single-bolt camshaft sprocket. Aftermarket options include standard 'silent' link-plate chains and upgraded double roller chains.
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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.