Adapter for Cabin Filter Installation on Jeep TJ

This adapter is for later model Jeep TJs (likely 2003-2006) that enables the use of a cabin filter for the HVAC system. These Jeeps never had cabin air filters, meaning all the dust you encounter on the road ends up blowing over you inside the cabin.

The adapter allows the use of a single late JK air filter cartridge. The proper air filter model is Fram FDC11777, but any other brand compatible with 2011-2017 Jeep Wrangler should work. They typically come in pairs (since JK uses two at a time), but you only need one for this model.

Installation Instructions:

• Remove the cowl between the windshield and hood.
• Remove the factory duct (if present) and install this adapter in its place.
• One of the air filters drops into place (make sure to respect the airflow direction arrows on the filter).

The adapter is made from two pieces for printability. The “base” is an adapter that goes around the factory flange and provides a flat surface for the “filter holder” to sit on. My printer was too small to fit either piece on the build plate, so there is another version split into four files so you can print them in pieces. In that case, the pieces are indexed to ensure they stay together. Some glue can be used to seal it all up, but the screws and indexing will keep it together sufficiently well without it.

You’ll want to print this in something temperature-resistant, like ABS/ASA or PETG. The image is regular black ABS with settings: 0.3mm layers, 2 top/bottom layers, and 30% cubic infill. It may not look pretty due to the thin top and bottom, but it’s strong enough that way.