Ive never been impressed by the factory installation of the air filter on my 360.
It is impossible to service properly without completely removing the canister which risks getting dirt into the induction tubing. You can loosen the mounting brackets and force it up on the rubber couplers to remove the cartridge but that risks dirt falling out of the pleated filter into the turbine inlet. I believe that was the cause of the impact damage on my turbo by the POs.
The air intake tube was about 6 feet long and sucked the dustiest air possible from this 2' x 2' x 2' mystery box in the rear corner. There is a louvered 10" x 10" inlet on the rear corner. The box is "isolated" from the rear by rubber blankets. There are huge gaps that allow air from the engine compartment and rear cowling into the box where this huge 8" vacuum cleaner hose happily ingesting anything that enters. One disadvantage of a rear engine is that it is in the dirtiest, dustiest position possible.
I experimented by relocating the existing canister.
I ran it that way on our spring trip for about 3000 miles and was happy with the results. It wasn't sealed off from the engine compartment so not truly a cold air inlet but no worst than the original. It did free up space in the engine compartment to relocate the coach batteries to the rack. That really worked out well!
After hours of research and searching I found an air cleaner that was perfect for the application. It's from a 2012 Freightliner M2. Its from Donaldson and uses the PowerCore axial flow filters. They boast 10x the efficiency over the pleated filters. Designed for 500 hp it should be overkill for the little 5.9L.
The new configuration uses the existing 4" to 5" 90 degree elbow and 5" aluminum tube with a 5" to 7" hump connector and the Freightliner filter.
I fabricated some baffling to seal off the air box and mounted the filter.
View looking in through the air inlet opening.
I'm very happy with the results. It's very easy to service through the side louvre. The filter design virtually eliminates the chance of getting dirt in the intake during service. The cartridges are $37 vs $70 for the stock cartridge. It has a safety filter to prevent FOD.