Mercury Montego Ignition Lock Cylinder: A Guide for the 1968-1977 Generations
If your Montego's key is sticking or won't turn, the problem is likely this simple, mechanical part.
- Verify your Montego's production date before ordering; the part changed mid-1973.
- Symptoms are almost always mechanical: the key sticks, binds, or won't turn.
- Replacement is a simple DIY task if you have a working key.
- There are no recalls for this part; failure is due to normal age and wear.
Is Your Montego's Ignition Lock Cylinder Failing?
After 50+ years of use, the original ignition lock cylinder in a Mercury Montego is a common failure point. The internal pins and tumblers wear down from thousands of key cycles. This wear can cause a range of frustrating problems that can leave you stranded. Before you suspect a more complex electrical issue, check for these classic signs of a bad lock cylinder.
Top 3 Failure Symptoms
- Key is Hard to Turn: You feel resistance, grittiness, or binding when trying to turn the key. It may feel like it's catching on something inside. This is the most common sign of worn internal tumblers.
- Key Won't Go In or Won't Come Out: The key may get stuck in one position (like 'Accessory' or 'On'), or you may have trouble inserting it all the way. This can happen if a tumbler is broken or jammed.
- Car Won't Start or Crank: You can insert the key, but it refuses to turn to the 'Start' position. Because the cylinder can't rotate, it can't activate the ignition switch, so nothing happens.
Important: Check Your Production Date
Ford made a design change to the ignition lock cylinder during 1973. There are different parts for vehicles built before and after May 14, 1973. Before ordering, verify your vehicle's production date on the driver's door jamb sticker to ensure you get the correct part.
Choosing the Right Aftermarket Lock Cylinder
Since new original Ford parts for a classic Montego are no longer made, you'll be choosing from aftermarket brands. Quality can vary, but even budget-friendly options are often sufficient for this simple mechanical part.
Brand Tiers
- Standard Ignition (Standard Motor Products): Often considered a premium aftermarket brand, Standard is trusted by professional mechanics. Their cylinders are known for using high-quality materials like brass tumblers and for meeting or exceeding original specifications for a smooth, reliable operation.
- Dorman: A well-known and widely available brand, Dorman provides a reliable, direct-fit replacement. They are a solid mid-tier choice that balances cost and quality, and their parts often come with clear instructions.
- Replacement / Store Brands: These are the most budget-friendly options. While they will get the job done, they may not have the same long-term durability or precision feel as premium brands. For a car that isn't a daily driver, this can be a perfectly acceptable choice.
| Part Type | Estimated Cost |
|---|---|
| New Aftermarket | $21.34 - $35.44 |
| New OEM (Ford) | Not Available |
| Used OEM (Junkyard) | $10 - $30 (Condition Varies) |
| Shop Labor | $50 - $150 |
Pro Tip: Inspect the Ignition Switch
While you have the lock cylinder out, it's a good time to inspect the electrical ignition switch it connects to. If your car has also been experiencing issues like stalling while driving or accessories cutting out, the switch may also be faulty. Replacing both at the same time can save you from doing the job twice.
Frequently Asked Questions
Can I replace the ignition lock cylinder myself?
Yes, this is a very feasible DIY job for most owners. If you have the key, the cylinder can be removed in about 10-15 minutes by turning it to the 'ACC' position and depressing a retaining pin with a paperclip or small punch. No special tools are required.
What do I do if I lost the key?
If you don't have a key that can turn the cylinder, it cannot be removed using the retaining pin method. The old cylinder must be drilled out to be removed. While possible for a DIYer, you may want to consult a professional or a locksmith for this procedure.
Will I need two keys after replacing the cylinder?
Yes. The new lock cylinder will come with its own set of keys. Your original key will still be needed for the doors and trunk. Some owners take the new cylinder to a locksmith to have it 're-keyed' to match their original keys before installation.
Are there any recalls for the Montego ignition lock cylinder?
No. A search of the National Highway Traffic Safety Administration (NHTSA) database shows no recalls for the ignition system on the 1968-1977 Mercury Montego. The widely publicized ignition recalls involved much newer GM vehicles and do not apply to this car.
Technical Specifications
OEM Part Numbers: D4AZ-11582-A
Mechanical, key-operated tumbler assembly. No electronic components. Comes with two new keys. Coded metal key required for operation.
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.