Differential Oil change? Questions...

Is there a 'how to' for this? i know its supposed to be done every 30k miles, so im looking to get it done... or rather do it myself. is it the same oil and differential as on the gt's? anyone do this? how difficult is it?

You need 2 bottles of 75-90w for the front and 1 bottle for the rear. the front is easy, you need a t70 torx to take the bolt off.

 

drain it, and you fill from the diff fluid checker on the pass side of the engine bay.

 

The rear was quite simple too. I believe its a 17mm and you just crank off the bottom bolt, drain. replug. then the bolt thats right above it... crank that off and use a sump pump type thing to pump the fluid into the rear diff till it starts to come out of the hole... which is almost 1 bottle. took me about 15 minutes for both w/ a set of ramps.

Can you take diff oil for recycling?

You should be able to. Its just regular gear lube.

My father in law is a master technician for Subaru and he said that it really isn't nessecary to change diff oil cause I asked him the same question. They have a 97 Legacy with 190,000 and he has never changed it. Kelly has a 97 Impreza with 165,000 and it hasn't been changed. I'm not telling you not to do it just informing you on what I was told.

The box end on a 1/2" drive fits the rear one. Do a search there is a how to somewhere. But its very straightforward as noted.

 

O.

I have to do my transmission next weekend and I was thinking of doing the differentials at the same time. I just finish changing the differential oil on the hooptie (not a subaru) and it was pretty straight forward. I wonder why we need to change it when on regular (not awd) cars you do not.

 

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Changing the diff oil seves two purposes to lube the gearset and operate the center diff effectively. Diff fluid breaks down and the more it deteriorates the harder shifts become and more wear and fear on your synchros etc. If a master tech told you not to change it let me know which dealership he works at so I make sure to NEVER take my Subaru there

 

It will run well past 100k on factory fluid but notchy Grundy shifts will be the norm.

When doing the rear diff, make sure to remove the fill bolt before removing the drain bolt. It'll drain better, and you won't get stuck with an empty diff that you can't fill, if you can't remove the bolt.