I can pee farther than you can pee...

As mav1178 said there was Still sludge after his first differential change. Yes there will be more after the first - yes it should be less sludge on the magnet than the first.

What you're saying is that it is Impractical not Illogical.

If you want to be Practical and Logical you can just drain the relatively virgin oil after 5k miles into a clean oil pan, clean the drain plug, and refill the differential with the same oil assuming it is just as good - which it should be.

No you completely misread what I wrote.

What I'm saying is this: the sludge/shavings will always be there. You change your oil based on the ability of the oil to protect the differential, not based on what sludge is left.

Same thing applies for the transmission, same thing for the engine.
For the average driver you follow the factory service interval.

I never said it was illogical, you said it. What I said is that this is absurd.

If you want to change it sooner, fine. Just don't claim it is better at removing contaminants until you have UOA done.

-alex

I change mine every Thanksgiving weekend. Haters be haters but I sleep well when I'm done and knowing that I extendent the life of "my car".

That's a great schedule.
 

Changing it more often is cool. Approaching 13K. Imma change mine next weekend.

Noob question: would a dealership service dept. be able to know you used non-OEM fluids? I know that can be a reason for warranty invalidation.

I call BS.

I think it just has to meet manufacturer's specs.

I don't think u can find it. It only comes in 5 gallon pails which means the dealer would have to do it?

Who cares? If they ask, you show them the oil specs.

As long as it is within the range suggested by the manufacturer, it is not an issue. Any dealer that argues otherwise doesn't deserve your business.

If you used something out of the range... then you're SOL.

-alex

My owner's manual calls for:

LS diff - 1.2 qt Toyota Genuine Differential Gear Oil LX
- other API GL-5 and SAE 75W-(85 or 90)

tranny - 2.3 qt Toyota Genuine MG Gear Oil special II
- other API GL-3 and SAE 75W-90

Here's what came out of mine today, 14K miles
https://lh5.googleusercontent.com/-4...516_150123.jpg
and the drain plug was covered in shavings.
https://lh3.googleusercontent.com/-U...516_115002.jpg

that mushroom marina looks tasty~

just wondering..what is the official recommended change interval from Subaru?