I've done the front diff and rear transmission on my mule for the past few years every year despite being driven for less than 300 miles/year. Does anyone think running it for two year interval at this mileage would make any difference in longevity if it's stored covered and outside? I use HPL for the diff/transmissionmission fwiw. TIA.
diff/trans fluid change frequency for mule
- Thread starter gasman556
- Start date
The short answer is no.
CleanSump
Site Donor 2026
No. With HPL 300 miles a year for two years is a cakewalk.
You don't need to change it that often, but it's still a cheaper hobby than golf if you wanna.
I looked that P169071 filter up on rockauto and it said it does not have an anti-drainback valve. I don't know if that is a factor in your application or not. It appears to be a Motorcraft FL1A equivalent, otherwise.
I emailed Donaldson and they said it did. I think the package says so too. Let me see if I can find that email/spec info....but definitely WOULD matter how this thing is mounted.
@ripcord of course I can't find it now
and donaldson's website indicates "no" on the spec sheet for ADBV. I emailed them again. I remember it having some sort of rubber/silicone/insert material here opposite the holes in the mounting side of the filters. I THINK that would indicate ADBV though I'm far from an expert. I'll close the loop with a pic of the filter to hopefully get some idea on whether or not it's a good idea or not. Again, thank you 
I'm guessing that FL1A sized filter is significantly over sized from stock? That would make the absence of an anti-drainback valve even more significant.
