Transmission Filter Kit Guide for 1985-1990 Kenworth K100E
Keep your heavy-hauler's transmission shifting smoothly by choosing the right filter kit.
- You must identify your specific transmission (e.g., Allison, Eaton Fuller) to buy the correct filter kit.
- Symptoms like whining, delayed shifting, or burnt fluid indicate it's time to check your transmission filter.
- For heavy-duty use, a quality brand like Wix is a reliable choice over a standard replacement.
- Replacing the filter is inexpensive maintenance that can prevent thousands of dollars in transmission repairs.
Is Your K100E's Transmission Acting Up?
The transmission in your Kenworth K100E is a complex and expensive piece of machinery. A simple and inexpensive transmission filter kit is your first line of defense against major repairs. When the filter gets clogged, it can't do its job, leading to low fluid pressure and potential damage. Ignoring the signs can turn a simple maintenance job into a transmission rebuild.
Symptoms of a Clogged Transmission Filter
🎬 Watch this video to see common signs of a clogged filter.- Whining or Buzzing Noises: If the transmission pump is struggling to pull fluid through a clogged filter, it can make a whining sound.
- Delayed Shifting or Hesitation: You might notice a pause when shifting from park into drive or reverse. The truck may also hesitate or feel sluggish when changing gears.
- Burnt Smelling Fluid: A clogged filter can cause the transmission to run hotter, which can burn the fluid. Burnt fluid is dark and has a distinct, acrid smell.
- Gear Slipping: The transmission may unexpectedly change gears or feel like it's not fully engaged.
- Visible Leaks: Increased pressure from a blockage can sometimes cause gaskets and seals to leak transmission fluid.
Don't Ignore the Signs
Driving with a severely clogged transmission filter can starve the transmission of the lubrication it needs, leading to catastrophic failure. If you notice any of these symptoms, it's time to inspect your filter and fluid.
Choosing the Right Aftermarket Filter Kit
For a classic workhorse like the 1985-1990 K100E, aftermarket parts are often the only option. The key is to choose a quality brand. Your truck was likely fitted with a manual Eaton Fuller or an automatic Allison transmission, so the most important step is to identify your specific transmission to ensure you get the correct kit. An ATP kit for an Allison transmission, for example, will not fit an Eaton Fuller.
Brand Quality: ATP vs. Wix
Both ATP and Wix are well-known names in the aftermarket filter world. For heavy-duty applications, brand reputation for quality components is key.
- Wix: Wix is a highly regarded brand in the heavy-duty industry, often mentioned alongside OEM suppliers like Donaldson and Fleetguard. They are known for robust construction and quality filter media that meets or exceeds OEM specifications. Many professional mechanics trust Wix for their reliability in demanding environments like trucking.
- ATP: ATP is a common aftermarket brand that offers a wide range of transmission parts. Their kits are designed to be an OE replacement and often include helpful features like special gaskets to aid installation. 🎬 Learn how ATP's 3rd Hand gaskets make installation much easier. However, some users have reported issues with gaskets being damaged due to packaging. While generally considered a standard replacement, they may not have the same heavy-duty reputation as Wix.
Pro Tip: Check the Gasket
When you receive your kit, inspect the pan gasket immediately. It should be flat and free of tears or severe creases, especially at the bolt holes. A damaged gasket will not seal properly and will cause leaks.
Cost of a New Transmission Filter Kit (1985-1990 Kenworth K100E)
The cost for a new aftermarket transmission filter kit is very reasonable, especially when compared to the cost of a transmission repair. Prices can vary based on the specific transmission your truck is equipped with and the brand you choose.
| Part Type | Price Range | Notes |
|---|---|---|
| New Aftermarket (e.g., ATP, Wix) | $12.56 - $94.18 | Price depends on the specific transmission (e.g., Allison, Eaton) and kit contents. This is the most common and available option. |
| Shop Labor | $100 - $250 | Varies by shop rate and location. The job typically takes 1-2 hours. |
Frequently Asked Questions
How often should I change the transmission filter on my K100E?
For a heavy-duty truck, it's good practice to change the transmission fluid and filter according to the manufacturer's service interval, or sooner if the truck operates in severe conditions. A general recommendation is every 30,000 miles, but you should consult your transmission's service manual for specific guidance.
Is it difficult to replace the transmission filter myself?
For someone with basic mechanical skills and tools, replacing a transmission filter is a manageable job. It involves draining the transmission fluid, dropping the pan, replacing the filter and gasket, and refilling with new fluid. It can be messy, but it is feasible for a DIY mechanic. The difficulty is rated as low to moderate.
🎬 See why internal filter debris is the leading cause of failure.Do I need a special kit for my Allison or Eaton transmission?
Yes, absolutely. Transmission filter kits are specific to the make and model of the transmission, not the truck itself. You must identify whether you have an Allison, Eaton Fuller, or another type of transmission to buy the correct part. Check for a data plate on the transmission housing to identify it.
What's the difference between a cheap and an expensive aftermarket kit?
The price difference often comes down to the quality of the filter media and the gasket. Higher-quality kits from brands like Wix or Donaldson use media designed for better filtration and durability under heavy use. They may also include a higher-quality, reusable-style pan gasket that provides a better seal.
Helpful Videos
Technical Specifications
OEM Part Numbers: Allison: 29558329, 29548988, 29548987 Eaton Fuller: K2170, 4304827, K1486
Kit must match the specific transmission model (e.g., Allison MD-300B, Eaton Fuller, etc.). Kits typically include filter(s), pan gasket, and O-rings.
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 K100E: