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Choosing the Right Transmission Filter Kit for Your 1997-2001 Western Star 5900

Keep your rig's transmission safe by learning how to select the correct filter kit for your specific build.

4 minutes to read 1997-2001 Western Star 5900
Difficulty
2/5
Est. Time
1.5 hrs
DIY Doable?
✅ Yes
Shop Labor
$150-$300
⚠️ Drivable, but... — You can drive with minor symptoms, but you risk severe transmission damage if the filter is badly clogged.
Key Takeaways
  • You must identify your specific transmission model (e.g., Allison, Eaton) by checking the data plate on the transmission housing before ordering a part.
  • A filter kit for a '97-'01 Western Star 5900 can range from a simple spin-on filter to a complex kit with multiple filters and gaskets depending on the transmission.
  • Both Wix and ATP are reputable aftermarket brands offering quality kits for this application.
  • Symptoms like whining, hard shifting, or overheating indicate a need for immediate inspection; a clogged filter could be a sign of a larger internal issue.
The transmission filter kit is vital for your Western Star 5900's health. Its main job is to trap harmful particles and debris from the transmission fluid. This clean fluid is essential for lubricating moving parts, cooling the transmission, and enabling smooth gear shifts. In a heavy-haul truck like the 5900, the transmission works under extreme stress, creating clutch material dust and tiny metal shavings. The filter stops this debris from damaging sensitive components like the valve body and torque converter, which could lead to expensive repairs.

First, Identify Your Transmission

Before you can buy a filter kit, you need to know exactly which transmission is in your 1997-2001 Western Star 5900. These trucks were built to order and could have several different transmissions, most commonly from Eaton Fuller (often manual or automated) or Allison (usually automatic). The filter kit is matched to the transmission, not the truck model.

Look for a metal data plate on the side of the transmission housing. This plate will have the manufacturer (e.g., Allison, Eaton) and the specific model number. This is the most important step; without this information, you will order the wrong parts.

Symptoms of a Clogged Transmission Filter

A clogged filter restricts fluid flow, which can starve the transmission. Watch for these warning signs:

  • Delayed or Hard Shifting: The transmission may hesitate before engaging a gear or shift more aggressively than usual.
  • Whining or Grinding Noises: A restricted filter can cause the transmission pump to whine as it struggles to draw fluid.
  • Leaking Fluid: While not a direct symptom of a clogged filter, it's a sign you need to inspect the transmission. A new gasket from a filter kit can solve many common pan leaks.
  • Overheating Transmission: Reduced fluid flow means less cooling, causing the transmission to run hot, which can quickly damage internal components.

Don't Ignore the Signs

If you experience severe symptoms like grinding noises or a transmission that won't engage, a clogged filter might be a sign of a much larger internal problem. A filter's main job is to catch debris from a failing component. Continuing to drive could lead to catastrophic failure.

Choosing Your Aftermarket Filter Kit: Brand Tiers

For the 1997-2001 Western Star 5900, aftermarket kits are a practical and high-quality choice. The two main brands you'll find are Wix and ATP. Both are well-regarded by mechanics.

Tier 1: WIX

Wix is a top name in filtration and is known for making high-quality, reliable products. Their kits for heavy-duty applications are built to meet or exceed OEM standards. You can trust a Wix kit to provide excellent filtration and fit correctly. Many professional mechanics default to Wix when an OEM part isn't readily available.

Tier 1: ATP

ATP is another strong contender, and they have a good reputation, especially for their gaskets. Many ATP kits include a unique fiber gasket designed to swell slightly with heat, creating a superior seal to prevent leaks. They also feature "third-hand" gaskets with undersized bolt holes that cleverly hold the bolts in place, making pan installation much easier.

Pro Tip: It's All About the Transmission Model

The price of a kit can range from about $12 for a simple spin-on filter to over $130 for a comprehensive kit. Allison automatic transmissions, for example, often require more complex kits with both internal and external filters, plus O-rings and gaskets. Manual Eaton Fuller transmissions may not have a filter at all, or only an external one. Always use your transmission model number to find the right kit.

Estimated Costs for Transmission Filter Replacement

Part/ServiceEstimated Cost
New Aftermarket Filter Kit$12.56 - $132.96
Shop Labor$150 - $300

Costs are estimates and can vary based on your location and specific transmission type.

Frequently Asked Questions

Which kit do I need for my truck?

It depends entirely on the transmission model installed in your truck. Check the data plate on the transmission itself for the manufacturer (like Allison or Eaton) and model number. Search for a kit using that number, not just "Western Star 5900".

Is Wix or ATP a better brand for my transmission filter?

Both are excellent aftermarket choices. Wix is widely known for its filter media quality. ATP is often praised for its innovative, leak-resistant gaskets. You can't go wrong with either brand, so choose based on availability and price for your specific transmission model.

How often should I change the transmission filter?

Follow the service interval recommended by your transmission's manufacturer (Eaton, Allison, etc.). For heavy-duty trucks, this is often done with every transmission fluid change. Regular fluid and filter changes are the most important thing you can do for transmission longevity.

Can I change the transmission filter myself?

For a mechanically inclined owner, this is a manageable job. It involves draining the fluid, dropping the transmission pan (which can be messy), replacing the filter and gasket, and refilling with the correct fluid. Ensure you have the right tools, a catch pan, and torque specifications for the pan bolts to avoid leaks.

Are there any recalls for the transmission filter on this truck?

No. There are no recalls or specific Technical Service Bulletins (TSBs) for the transmission filter kit on the 1997-2001 Western Star 5900. This is normal, as filters are considered standard maintenance items.

Technical Specifications

Varies based on the installed transmission. Common kits exist for Allison 3000/4000 series and various Eaton Fuller models.

Wrenchy
Article researched & written by
Go-Parts' AI research assistant. Every article is backed by live web research, verified OEM data, and real technician knowledge — so you get accurate, up-to-date information you can trust.
Meet Wrenchy → Updated Jul 21, 2026

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.

Year Coverage
This article covers the Transmission Filter Kit for:
  • Western Star 5900: 19971998199920002001
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