Transmission Filter Kit Guide for 1991-2001 Kenworth C500 Trucks
Keep your automatic transmission shifting smoothly and avoid costly damage by choosing the right filter kit.
- This guide is ONLY for C500s with an automatic transmission; verify your truck's configuration before buying.
- Symptoms like hard shifting, whining noises, or a burning smell point to a clogged filter that needs immediate attention.
- Quality aftermarket brands like Wix are a reliable choice for this part, but always inspect the included gasket for damage before installation.
- Be aware of the open NHTSA recall for 1999-2001 models regarding a firewall circuit breaker, which poses a fire risk.
Is This Guide For Your Truck?
This guide is for 1991-2001 Kenworth C500 models equipped with an automatic transmission. The C500 was available with manual, automatic, and automated-manual transmissions (AMTs). Manual transmissions do not use this type of filter kit. Always verify your truck's specific transmission before ordering parts.
Symptoms of a Clogged Transmission Filter
When your transmission filter is clogged, your truck will give you clear warning signs. Ignoring them can lead to serious transmission failure. Look out for:
- Hard or Delayed Shifting: The truck may hesitate, slip between gears, or feel sluggish when shifting. You might notice the engine RPMs increase without a corresponding increase in speed.
- Unusual Noises: A distinct whining or buzzing sound from the transmission area is common. This often means the transmission pump is straining to pull fluid through the clogged filter. You might also hear rattling or clunking sounds.
- Fluid Leaks: Increased pressure from a blockage can force transmission fluid past gaskets and seals, causing red or brown fluid spots under your truck.
- Burning Smell: A clogged filter can cause the transmission to overheat, giving off a distinct burning smell. This indicates the fluid is breaking down and no longer protecting the transmission properly.
- Contaminated Fluid: If you check your transmission fluid and it appears dark, dirty, or has a burnt smell, the filter is likely not doing its job.
Choosing the Right Aftermarket Part
For a part like a transmission filter, you don't always need to pay for an OEM part. Quality aftermarket brands offer reliable performance. The key is to choose a reputable brand that provides a high-quality filter and, just as importantly, a durable gasket.
Brand Quality Tiers
- Better (Wix): Wix is a well-regarded brand in the heavy-duty truck industry for its quality and reliability. Forum users and mechanics often trust Wix filters for their good fit and performance, considering them a solid alternative to OEM. These kits provide confidence that the filter media and construction meet the demands of a hard-working truck.
- Good (ATP): ATP is another established aftermarket brand that offers functional and budget-friendly filter kits. Some professional mechanics have used them for years in fleet vehicles. ATP kits often include their "3rd Hand" gasket, which has small tabs to hold bolts in place during installation. However, be aware that some users have reported issues with gaskets being bent or torn during packaging, so inspect the gasket carefully upon receipt.
Pro Tip: Regardless of the brand, the gasket is critical. A poor-quality or damaged gasket will cause leaks. Many professional installers prefer to use a separate, high-quality gasket from a brand like Fel-Pro if the one in the kit seems flimsy.
Known Issues: 1999-2001 Kenworth C500 Recall
The National Highway Traffic Safety Administration (NHTSA) issued a recall for nearly 2,000 Kenworth C500, T600, T800, and W900 trucks from model years 1999-2001. The issue involves incorrectly attached power leads on an optional firewall-mounted circuit breaker. This defect could leave the main cab power unprotected, potentially leading to an electrical arc and fire if a short circuit occurs. While not related to the transmission, it is a critical safety issue to be aware of for these model years.
Cost of Replacing a Transmission Filter Kit
| Part Type | Part Cost | Labor Cost |
|---|---|---|
| New Aftermarket | $12.56 - $130.49 | $150 - $300 |
| New OEM | $75 - $200 |
Frequently Asked Questions (FAQ)
How often should I change the transmission filter on my C500?
Service intervals for heavy-duty trucks vary widely based on use. For severe duty, some recommend changes as often as every 30,000 miles. For normal highway use, the interval can be 100,000 miles or more. Always consult your owner's manual or a trusted Kenworth mechanic for the schedule that matches your truck's specific transmission and workload.
Can I just change the fluid and not the filter?
It is not recommended. The filter traps contaminants, and leaving a dirty filter in place with fresh fluid is counterproductive. A filter change is a standard part of a transmission service when the pan is dropped.
Can I reuse my old transmission pan gasket?
Some transmissions come with a reusable rubber-and-steel gasket. If yours is in excellent condition (not brittle, cracked, or deformed), it can sometimes be reused. However, most filter kits come with a new gasket, and it is generally best practice to replace it to ensure a leak-free seal, especially if it's a standard cork or composite gasket.
What kind of transmission fluid should I use?
Using the correct transmission fluid is critical. The type of fluid depends on the specific automatic transmission model in your C500 (e.g., Allison, etc.). Using the wrong fluid can cause shifting problems or severe damage. Check your owner's manual or the dipstick itself, which often has the fluid specification stamped on it.
Technical Specifications
Kit contents typically include the transmission filter and a pan gasket. Some kits may include a new O-ring or seal. The specific filter design (e.g., deep vs. shallow pan) must be matched to the exact automatic transmission model installed in the truck (e.g., Allison AT545, etc.).
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.
- Kenworth C500: