wagonmaster2 wrote:
Maybe I've missed an answer to this question in all the great responses but I was wondering how long to run the High Efficiency filters assuming the fluid analysis says the fluid is okay seeing as how Allison says to change the filters every 36 months?
Should the filters be changed every 36 months even if the fluid can be run 60-84 months, or even longer? Mileage only runs around 4,000-5,000 miles per year.
Wagonmaster2
2004 Meridian 36G Allison 3000 Cat C-7 330 HP
Wagonmaster2,
Here's the deal. I believe you can run filters longer but you'll need to run oil analysis and it "must" include particle count and should include ISO Cleanliness Code. Oil analysis will tell you all you need to know about the fluid life (provided you're also getting the TAN (Total Acid Number) information. The only thing a typical oil analysis won't tell you is how much debris (particles/millileter) and the size of the particles (micron sizes) that are circulating through your system. Allison filters are sized to pass finer particles (approximately 30 microns or smaller)so that the filters won't "load up" in a short amount of time. Anything above 30 microns should be trapped by the filter. Generally, the larger the particle, the less there are of them. Tiny particles (around 4-14 microns in size) are abundant in most systems. These tiny particles generally due little harm the transmission unless they are very hard particles like sand (which shows up as excessive "silicon") in an oil sample.
Bottom Line: All systems are different in the way the collect debris and your duty cycle and location are a big part of what gets picked up through the breather. So, filters are kind of difficult to manage. It can be done but it takes particle count data at a bare minimum to do it. Most folks may not want to take that on.
