Ignition Lock Cylinder Guide for the 1975-1979 Buick Roadmaster
Having trouble finding an ignition lock cylinder for your classic Roadmaster? Here’s what you need to know.
- Search for a generic '1970s GM ignition lock cylinder' instead of a Roadmaster-specific part.
- The job requires special tools, including a steering wheel puller and a lock plate compressor, which can often be rented.
- Brands like ACDelco, Standard Motor Products, and Dorman are reliable aftermarket choices.
- Before starting the repair, test a spare key to ensure your problem isn't just a worn-out key.
Why You Can't Find a Roadmaster-Specific Ignition Cylinder
If you're searching for an ignition lock cylinder specifically for a 1975-1979 Buick Roadmaster, you likely won't find one. This isn't because the part is unavailable; it's because your Roadmaster uses a standard ignition lock cylinder common to most General Motors (GM) cars and trucks from the 1970s through the early 1990s. To find the right part, you should search for an ignition lock cylinder for this era of GM vehicles, which will fit your car perfectly.
Signs of a Failing Ignition Lock Cylinder
When the lock cylinder starts to fail, it gives clear warning signs. Ignoring them can lead to being unable to start your car. Common symptoms include:
- Key is hard to turn: You might feel resistance or have to jiggle the key to get it to turn to the 'On' or 'Start' position. This is often due to worn internal tumblers.
- Key gets stuck: The key may not go in smoothly or may get stuck in the cylinder in any position.
- Car won't start intermittently: You might turn the key and nothing happens, but it works on the second or third try. This indicates a developing mechanical issue inside the cylinder.
- The cylinder feels loose: Excessive play or looseness when the key is inserted is a sign of significant wear.
- Engine starts without a key: In rare cases of extreme wear, the lock mechanism can fail entirely, allowing the car to be started without a key.
Don't Confuse the Cylinder with the Switch
The ignition lock cylinder is the mechanical part your key goes into. The ignition switch is the electronic component that the cylinder activates. If your electrical accessories (radio, lights) work but the car won't crank, the problem could be the switch, not the cylinder.
Choosing the Right Aftermarket Part
Since new original GM parts are no longer made, you will be choosing between New Old Stock (NOS) or new aftermarket parts. For a vehicle of this age, a quality aftermarket part is a reliable and cost-effective choice.
- ACDelco: As the original equipment manufacturer for GM, an ACDelco-branded cylinder is the closest you can get to the factory part. If you can find one, it's an excellent choice for fit and durability.
- Standard Motor Products (SMP): A well-regarded aftermarket brand that produces quality replacement parts. Their lock cylinders often use durable materials like brass tumblers and die-cast zinc cores.
- Dorman: Dorman makes a wide range of replacement parts and offers ignition lock cylinders that cover these older GM vehicles. They are a common and accessible option found in most auto parts stores.
Forum discussions among classic GM owners suggest that while an original GM part is ideal for longevity, a reputable aftermarket cylinder is perfectly suitable. Cheaper, unbranded parts may use lower-quality internal springs and tumblers that can wear out more quickly.
Check Your Key First
Before replacing the cylinder, check your key. A key that is heavily worn can cause symptoms similar to a bad lock cylinder. Try using a spare key if you have one. If the spare works perfectly, you may only need a new key, not a whole new cylinder.
Replacement Cost
Replacing the ignition lock cylinder is a common repair. The part itself is not expensive, but the job requires some labor and special tools. Prices are for the common GM part that fits your Roadmaster.
| Part Type | Estimated Cost |
|---|---|
| New Aftermarket (Dorman, SMP) | $15 - $40 |
| New OEM (ACDelco/NOS) | $50 - $100+ (Varies by availability) |
| Shop Labor | $100 - $200 |
Frequently Asked Questions
Is this a difficult repair to do myself?
This repair is considered moderately difficult. It requires removing the steering wheel and using special tools like a steering wheel puller and a lock plate compressor to access the cylinder. While it is feasible for a DIY mechanic with the right tools, a beginner may find it challenging.
What tools are required for the job?
You will need a basic socket set, screwdrivers, a steering wheel puller, and a steering column lock plate compressor tool. Most auto parts stores offer these specialty tools as part of a loaner program.
Will the new cylinder come with keys?
Yes, all new aftermarket ignition lock cylinders come with a new set of two pre-coded keys.
Are there any recalls for the ignition on my 1975-1979 Roadmaster?
No, searches of the National Highway Traffic Safety Administration (NHTSA) database did not show any recalls or technical service bulletins (TSBs) related to the ignition lock cylinder for this specific year range of Buick Roadmaster.
Technical Specifications
Fits non-airbag GM steering columns with side-bar ignition. Uses the square-head GM key design common in the 1970s. The cylinder is typically held in place by a retaining screw inside the steering column, accessible after removing the lock plate.
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.