Choosing the Right Transmission Filter Kit for Your 1979-1981 Dodge St. Regis
Keep your classic Dodge shifting smoothly by picking the correct new aftermarket transmission filter for your specific engine and transmission.
- You MUST identify your transmission (A904 or A727) to get the correct pan gasket.
- Wix and ATP are highly-regarded aftermarket brands for this part.
- Symptoms like delayed shifting, whining noises, or a burning smell mean your transmission needs service immediately.
- For this vehicle, new aftermarket parts are the only option, and they are a perfectly reliable choice.
Is Your St. Regis Showing Signs of a Clogged Transmission Filter?
An automatic transmission is a complex hydraulic system. If the fluid can't flow freely because of a clogged filter, you'll start to notice problems. Pay attention to these symptoms, as they can signal that it's time for a transmission service.
- Delayed or Rough Shifting: The car may hesitate when you shift from park into drive, or shifts might feel harsh and clunky.
- Strange Noises: You might hear a whining sound that changes with engine speed, or rattling and grinding noises when the car is in neutral or while driving.
- Fluid Leaks: A clogged filter can cause pressure to build up, forcing fluid out past seals and gaskets. Look for reddish fluid spots under the car.
- Burning Smell: Restricted fluid flow leads to overheating. This can burn the transmission fluid, creating a distinct acrid smell.
A Note on Original Equipment (OEM) Parts
For a vehicle like the 1979-1981 Dodge St. Regis, new original equipment (OEM) Mopar transmission filters are effectively unavailable. The market for these parts consists entirely of new aftermarket manufacturers. This is not a concern, as many aftermarket brands produce high-quality components that meet or exceed the original specifications from the era.
Choosing the Right Aftermarket Filter Kit
The most critical step is identifying your transmission. Your St. Regis will have either an A904 transmission (usually with the Slant-6 engine) or the heavier-duty A727 (usually with the 318 and 360 V8 engines). While the filter itself is often the same, the pan gaskets are different. Some kits helpfully include gaskets for both.
Brand Quality Tiers
Not all aftermarket parts are created equal. Here’s a breakdown of the available brands to help you choose.
- Premium Aftermarket (Best Quality): Wix is a top-tier filter manufacturer with a strong reputation for quality and performance. They are often considered a benchmark in the aftermarket and a reliable choice for ensuring long service life.
- Quality Aftermarket (Good Quality): ATP is a dedicated transmission parts specialist. They are a well-regarded brand in the repair community and a solid choice for a standard replacement. They are known for their "third-hand" gaskets which have undersized holes to hold bolts during installation, though you should always inspect the gasket for damage from being folded in the box.
- Standard Aftermarket (Good Value): Brands like Pioneer Cable and Premium Guard offer a good balance of quality and price. They are designed as stock replacements and are a suitable choice for owners looking for a reliable, budget-friendly option for regular maintenance.
| Part Type | Price Range | Notes |
|---|---|---|
| New Aftermarket | $17.22 - $56.59 | This is the only realistic option. Price varies by brand quality and kit contents. |
| New OEM | Not Available | Original Mopar parts for this model are long out of production. |
| Shop Labor | $100 - $200 | This is a common and relatively quick job for most repair shops. |
Pro Tip: Check the Gasket
When you receive your kit, immediately unpack it and lay the gasket on a flat surface. Gaskets that are folded tightly in small boxes can sometimes be creased or torn. If the gasket is damaged, do not use it, as it will likely leak.
Frequently Asked Questions (FAQ)
How often should I change the transmission filter on my St. Regis?
For a classic vehicle under normal driving conditions, a good interval is every 30,000 miles or every 2-3 years, whichever comes first. If you frequently drive in harsh conditions, consider servicing it more often.
Do I need to know if I have an A727 or A904 transmission?
Yes, this is very important. The main difference for this job is the shape of the transmission pan and its gasket. The A727 has a more irregular pan shape with a dog-leg corner, while the A904 pan is more square. Counting the 14 pan bolts is also a good confirmation. Always verify your transmission type before ordering.
What kind of fluid should I use for my St. Regis?
The original specification for these transmissions was DEXRON/MERCON or Chrysler ATF+ fluid. Modern DEXRON III/MERCON fluid is a suitable and commonly used replacement. Always check the fluid manufacturer's recommendations to ensure it is compatible with older Chrysler transmissions.
Is the gasket that comes with the kit good enough?
Generally, yes. However, the quality can vary. Cork gaskets are common but can be brittle. Rubber or composite gaskets are often more durable and forgiving. Some mechanics prefer to use a thin layer of RTV sealant with the gasket (or instead of a cork gasket) for a better seal, but be careful not to use too much, as excess can break off and clog the new filter.
Technical Specifications
OEM Part Numbers: 3515966
Fits Chrysler TorqueFlite A904 and A727 automatic transmissions. Kits typically include one filter and one or two pan gaskets (one for each transmission type). The pan has 14 bolt holes.
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.