A Guide to Engine Timing Sets for the 1968-1977 Mercury Montego
Understanding the critical timing set upgrade your classic Montego's V8 engine needs to stay reliable.
- If your engine is original, you MUST replace the factory nylon-toothed timing gear to prevent catastrophic failure.
- Upgrading to an all-metal, double roller timing set is a cost-effective way to improve durability and engine accuracy.
- When the timing set is replaced, you must drop and clean the oil pan to remove all plastic debris.
- The timing set is specific to your engine (302, 351W, 351C, etc.), not the Montego model, so identify your engine before ordering.
The Most Important Part to Replace on Your Montego's Engine
If you own a 1968-1977 Mercury Montego with its original V8 engine, the most important maintenance item to address is the factory timing set. Ford V8 engines of this era were built with a camshaft gear that had nylon plastic teeth. Over decades, this plastic becomes brittle and breaks apart. These small plastic chunks fall into the oil pan, where they can be sucked into the oil pump pickup screen, clogging it and starving the engine of oil. This can lead to catastrophic engine failure. Any aftermarket replacement is an upgrade because it will use all-metal gears.
Symptoms of a Failing Timing Set
A worn or failing timing set will give you clear warning signs. Ignoring them can lead to your car leaving you stranded or causing severe engine damage.
- Engine Rattle: The most common symptom is a rattling or clattering sound from the front of the engine, especially noticeable at idle or on startup. This is the sound of a loose, stretched timing chain hitting the inside of the timing cover.
- Rough Idle and Misfires: As the chain stretches, the camshaft and crankshaft timing becomes inaccurate, leading to a rough idle, engine stumbling, and misfires.
- Loss of Power: Your Montego may feel sluggish and slow to accelerate because the valve timing is no longer optimal.
- Backfiring: Incorrect timing can cause fuel to ignite at the wrong time, leading to backfires through the carburetor or exhaust.
- Metal or Plastic in Oil: When changing your oil, finding small metal shavings or bits of plastic in the drained oil or filter is a sure sign that the timing gear is disintegrating.
Choosing the Right Aftermarket Timing Set
Since an original-style nylon gear is not recommended, you will be choosing between different types of all-metal aftermarket sets. The choice depends on your budget and how you use your Montego.
Tier 1: Standard Replacement Sets
These are the most affordable options and are a solid upgrade from the factory parts. They typically feature a cast iron camshaft gear, a steel crankshaft gear, and a standard-duty 'silent' link-belt style chain. Brands like Melling and standard-line Cloyes offer quality kits in this category that are perfect for a daily driver or stock restoration.
Tier 2: Heavy-Duty & Performance Sets
For added durability and performance, a double roller timing set is the best choice. These kits feature a true dual-row roller chain, which is stronger and creates less friction than a standard chain. They often come with multi-keyway crank sprockets, allowing a builder to advance or retard cam timing for performance tuning. Look for brands like Cloyes True Roller, Melling Select Performance, Edelbrock, and Ford Performance. For most owners, a double roller set provides excellent peace of mind and reliability for a small increase in cost.
Warning: Clean the Oil Pan
When replacing a failed original timing set, it is critical to remove the oil pan and thoroughly clean it and the oil pump pickup screen. Failure to remove all the old nylon debris can lead to oil starvation and engine failure even after you've installed a new timing set.
Pro Tip: While You're In There...
Replacing the timing set requires removing the water pump and timing cover. This is the perfect time to replace the water pump, thermostat, and all related gaskets. Also, carefully inspect the timing cover for corrosion where the coolant passages are. These covers are known to corrode from the inside out, causing coolant leaks that can be mistaken for a bad water pump gasket.
Cost of Replacing a Mercury Montego Timing Set
| Part Type | Estimated Cost |
|---|---|
| New Aftermarket (Standard) | $30 - $70 |
| New Aftermarket (Double Roller) | $70 - $152 |
| Shop Labor | $450 - $800 |
Note: Costs are estimates and can vary based on your specific engine, location, and the parts you choose. Labor costs are higher if the oil pan must be removed.
Frequently Asked Questions
Do I really need to replace my original timing set if it's not making noise?
Yes. The nylon teeth on the original cam gear fail due to age, not just mileage. It could fail without warning, potentially causing major engine damage or leaving you stranded. It is considered essential preventative maintenance on any 1960s-1970s Ford V8.
What is a 'double roller' chain and is it worth it?
A double roller chain is like a heavy-duty bicycle chain with two rows of rollers and links, making it much stronger and more accurate than the stock 'silent' chain. For the small price difference, it is highly recommended for improved durability and engine longevity.
Which timing set fits my Montego?
The timing set is specific to the V8 engine in your car, not the Montego model itself. You must identify if you have a 302, 351W, 351C, 351M, 400, 429, or 460 V8, as they all use different timing sets. Ordering the wrong part is a common mistake.
Which brand is the best?
For most owners, Melling and Cloyes offer excellent quality and value. Both are trusted names. Performance brands like Edelbrock and Ford Performance are also top-tier choices, especially if you are rebuilding the engine for more power. Avoid unbranded, budget kits, as some have been shown to have excessive chain slack right out of the box.
Technical Specifications
The primary specification is the type of chain: a standard 'silent' link-belt chain or a more durable 'double roller' chain. The specific set required depends entirely on the Ford V8 engine installed in the vehicle (e.g., 302, 351W, 351C, 400, 460).
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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.
- 🛍️ Shop This Part
- The Most Important Part to Replace on Your Montego's Engine
- Symptoms of a Failing Timing Set
- Choosing the Right Aftermarket Timing Set
- Tier 1: Standard Replacement Sets
- Tier 2: Heavy-Duty & Performance Sets
- Warning: Clean the Oil Pan
- Pro Tip: While You're In There...
- Cost of Replacing a Mercury Montego Timing Set
- Frequently Asked Questions
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