How to install a cabin filter

RMETeeJay

TJ Addict
Supporting Member
Joined
Sep 30, 2019
Messages
1,042
Location
CO, USA
@Chris for your approval to be added in the TJ How-to Guides sub.

I regularly drive in very dusty conditions, and got tired of the lack of cabin air filtration. I tried recirculate mode, but as soon as I'd change it back to fresh I'd get a blast of the dust that had built up. I wanted to use an actual cabin filter and not modify the stock equipment. This is what I came up with and it works great.

Note that these instructions are for the later style intake configuration (I think 2000-2006?). I'm not sure I'd do it on the earlier version because it's more exposed to water, etc. but it might work.

I picked up this filter from Wally World for $20. You can cut 2 filters out of it, so $10/filter.
01_s.jpg


Remove the wipers by sliding the catch by the shaft and pulling straight out. Raise the hood, and remove the rubber seal between the hood and the cowl. Remove the cowl (2 screws behind the seal, 1 in the center near the intake, and 4 up by the windshield). Remove the cabin air intake cover (3 screws).

Cut out a piece of cardboard slightly larger than the intake opening. Place it over the opening, and press down firmly where it touches to create an impression.
02_s.jpg


03_s.jpg


Cut out your template, ignoring the 3 indentations for the screws and cutting straight across them.

Lay your template on the filter, and trace out both at the same time because once you begin cutting, it will accordion out. To make sure the filter will fit tightly and securely, make your tracing slightly larger than the template. Use good, sharp scissors to cut both filters out.

04_s.jpg


05_s.jpg


Insert the filter so it's just under the cover. Arrange the pleats so they are equal distance from each other (better than this photo shows 😜).
06_s.jpg


Reassemble the cover, cowl and seal. Mark your date/mileage in your maintenance log. For passenger cars, replacement is typically at 30K. I plan to change mine every other oil change.
 

SkylinesSuck

TJ Expert
Supporting Member
Joined
Mar 28, 2020
Messages
3,424
Location
Northern VA
I wound up removing mine. I compared the airflow before and after and it was considerably reduced. I plan to go back in the future and rig something up with more surface area on the filter.
 
  • Like
Reactions: SailorEd

L J

lightbars before lockers
Supporting Member
Joined
Nov 26, 2017
Messages
4,695
Location
🤡🌎
I wonder if a piece of magnetic sign would stick well enough to keep dust out of the HVAC.
 

707kevin

100% More Rubicon!
Supporting Member
Joined
Aug 18, 2019
Messages
633
Location
Oregon
I wound up removing mine. I compared the airflow before and after and it was considerably reduced. I plan to go back in the future and rig something up with more surface area on the filter.

Maybe a 2" this home hvac panel with a low MERV rating?
 

Chief Brohician

1 Owner 1998 TJ Sport Hardtop.
Supporting Member
Lifetime Supporting Member
Joined
Apr 25, 2019
Messages
283
Location
Guntersville, AL
I wonder if panty hose would do the trick on the early versions for the TJ? Cut bigger and use magnets to hold in place kind of idea. Possibly on the latter TJ's.
 

TurboTJ

TJ Addict
Supporting Member
Joined
Jan 5, 2019
Messages
1,018
Location
Walnut Creek, CA
I wonder if a piece of magnetic sign would stick well enough to keep dust out of the HVAC.

I am going to try. On our last trip we flat towed the Jeep over a couple of hundred miles of dusty dirt roads. The resulting dust in the cabin (and everywhere else) was horrible. I bought some magnetic sheets to try on the front and rear vents for the next trip.
 
  • Like
Reactions: L J
OP
RMETeeJay

RMETeeJay

TJ Addict
Supporting Member
Joined
Sep 30, 2019
Messages
1,042
Location
CO, USA
I wonder if panty hose would do the trick on the early versions for the TJ? Cut bigger and use magnets to hold in place kind of idea. Possibly on the latter TJ's.

What does the early opening look like? Why doesn't it work?

I think the panty hose would deal with larger particles well, but still let dust through. Try it and report back.

The reason I went with a cabin filter is because pleats excel at trapping fine particles and dust. A con to pleats is more restricted airflow compared to flat filters. Because of that, I think it's important to make sure that the spacing is even between pleats to maximize the exposed medium without causing bunched up sections that restrict airflow.

My walmart only had Fram brand cabin filters and the medium was the same in all of the models I checked. Maybe a different brand's pleated filter would allow more airflow due to different medium and/or pleat spacing?
 
  • Like
Reactions: Chief Brohician

Chief Brohician

1 Owner 1998 TJ Sport Hardtop.
Supporting Member
Lifetime Supporting Member
Joined
Apr 25, 2019
Messages
283
Location
Guntersville, AL
What does the early opening look like? Why doesn't it work?

I think the panty hose would deal with larger particles well, but still let dust through. Try it and report back.

The reason I went with a cabin filter is because pleats excel at trapping fine particles and dust. A con to pleats is more restricted airflow compared to flat filters. Because of that, I think it's important to make sure that the spacing is even between pleats to maximize the exposed medium without causing bunched up sections that restrict airflow.

My walmart only had Fram brand cabin filters and the medium was the same in all of the models I checked. Maybe a different brand's pleated filter would allow more airflow due to different medium and/or pleat spacing?

I will take my '98 cowl off this weekend and take pictures for reference. I have often wondered how to put a filter in to lessen dust and smells from the outside.
 
  • Like
Reactions: RMETeeJay

somebuckaroo

New Member
Joined
Nov 28, 2022
Messages
5
Location
Atlanta
I did something similar with a knock-off "R-0990" air filter designed to fit a 2000s era Kawasaki Ninja 250. The filter fits perfectly down into the cowl opening. I made a strap to prevent the passenger-side of the filter from falling down into the air box, and used aluminum tape to seal up the gaps. Air flows in the reverse direction through the filter, but I don't think that matters for this application. The filter does noticeably restrict airflow.
1669642102390.jpg

1669642127079.jpg

1669642142041.jpg
 
  • Like
Reactions: Chris

SkylinesSuck

TJ Expert
Supporting Member
Joined
Mar 28, 2020
Messages
3,424
Location
Northern VA
I wonder if the filter media is more of a restriction or the size of those inlet holes. Might grab one and mess with it. Maybe try and cut the "top" open much more.
 

somebuckaroo

New Member
Joined
Nov 28, 2022
Messages
5
Location
Atlanta
I wondered the same, but haven't gotten around to cutting it open. I used a "Hifrom" brand filter, which is a knock-off of K&N at 1/3 the price. The filter housing is a stiff silicone rubber that is difficult to cut cleanly, and tape does not stick very well to it either. I would be somewhat concerned that the rubber material may crack/split when cut. I'm not sure if the genuine K&N filter is made from a more suitable rubber.