Peterbilt 348 Transmission Filter Kit Replacement Guide (1981-1985)
Keep your classic Peterbilt 348 shifting smoothly by choosing the right transmission filter kit for your specific setup.
- The filter kit is matched to your transmission model (e.g., Eaton, Allison), not the Peterbilt 348 truck model.
- Before ordering, find the ID tag on your transmission to get the exact manufacturer and model number.
- Most manual transmissions in these trucks use an air filter regulator for shifting ranges, not an internal fluid filter.
- ATP is a standard aftermarket brand; always inspect the new pan gasket for damage before starting the installation.
Identifying the Correct Transmission Filter Kit
Before buying a transmission filter kit for your 1981-1985 Peterbilt 348, you must know that the part is transmission-specific, not truck-model-specific. During this era, Peterbilt used various transmissions from different manufacturers, most commonly manual transmissions from Eaton Fuller or Spicer, and sometimes automatic transmissions from Allison. You must identify which transmission is in your truck to get the correct filter kit.
Pro Tip: Find the Transmission ID Tag
Look for a metal tag on the side of your transmission housing. This tag will list the manufacturer (e.g., Eaton, Spicer, Allison) and the specific model number. Use this model number when searching for a filter kit to guarantee a perfect fit.
Manual vs. Automatic Transmission "Filters"
It's important to understand the difference based on your transmission type:
- For Automatic Transmissions: The kit is a traditional fluid filter found inside the transmission oil pan. It usually includes the filter and a new pan gasket. This is the most common understanding of a transmission filter kit.
- For Manual Transmissions: Many heavy-duty manual transmissions, like those from Eaton Fuller, do not have an internal fluid filter. The part sometimes called a "filter" in this context is an air filter regulator for the range selector. This part cleans the air used to shift between high and low ranges. If you have a manual, confirm which part you actually need.
Choosing the Right Aftermarket Part
For a vehicle from this era, aftermarket parts are the most common and accessible option. Original equipment (OEM) parts may no longer be available. When looking at aftermarket brands, quality and fitment are key.
ATP Transmission Filter Kits
ATP is a widely available aftermarket brand that produces transmission filter kits designed to meet original specifications. Reviews from mechanics and DIYers are generally positive, often citing them as a good value. Some kits feature a "3rd Hand Pan Gasket" with guide holes that hold the bolts, making it easier to install the pan from underneath the truck. However, it's always a good practice to inspect the gasket as soon as you receive the kit. Gaskets can sometimes be folded for packaging, which might create a weak spot.
| Part or Service | Estimated Cost |
|---|---|
| New Aftermarket Kit (ATP) | $94.18 |
| Shop Labor for Installation | $150 - $300 |
Note: Labor costs are estimates for a standard transmission service and can vary by shop and location.
Frequently Asked Questions (FAQ)
How often should I change the transmission filter?
For a heavy-duty truck like the Peterbilt 348, you should follow the service intervals recommended by the transmission manufacturer (Eaton, Allison, etc.), not Peterbilt. Typically, the filter is changed along with the transmission fluid. For vehicles under severe use, more frequent changes are recommended.
What are the signs of a clogged transmission filter?
Symptoms of a clogged filter include hesitant or rough shifting, difficulty getting into gear, a whining noise from the transmission, or fluid leaks. In severe cases, it can lead to the transmission overheating or slipping out of gear.
What is included in the ATP transmission filter kit?
A typical kit for an automatic transmission includes the filter itself and a new pan gasket. Some kits may also include new O-rings or seals depending on the application requirements.
Can I replace the transmission filter myself?
Yes, for someone with mechanical experience, this is a manageable job. It involves safely raising the vehicle, draining the fluid, removing the transmission pan, replacing the filter and gasket, and refilling with the correct type and amount of fluid. Ensure you have the right tools and follow proper safety procedures, as you will be working under the vehicle.
Technical Specifications
Kit contents are specific to the transmission model. Automatic kits typically contain one filter and one pan gasket. Manual transmission 'filter' kits are often air system regulators.
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.
- Peterbilt 348: