If this is the first time, I would say yes. First, most manufacturers will tell you oil is stable for about 5 years in a sealed bottle. In the drive system, you're good for about 3 years. Mileage varies depending on driving conditions so 60k-100k KM is usually a good time to change oil. Going over isn't going to blow anything up, it will just speed up wear as contamination accumulates in the oil.

 

Moving thread to Gen 5; it doesn't belong in News and Media.

 

Any good 75W90 gear oil is fine for the diffs but I'd choose a synthetic. If you aren't 110% sure of the plug locations (and in posession of the FSM for your vehicle) I would suggest leaving this job to a professional familiar with Subaru CVTs.

 

Can we assume your talking only about the rear diff ? Hint, make sure you can remove the fill plug first, before you drain it and find out you can't remove the fill plug.

 

At my dealership to change out the differential fluid after taxes is 200 dollars just had mine done at 40 thousand miles. You have to have your Subaru level in all directions to do this so it’s just easier to have the dealership do it no guesses on anything.

 

At my dealership to change out the differential fluid after taxes is 200 dollars just had mine done at 40 thousand miles. You have to have your Subaru level in all directions to do this so it’s just easier to have the dealership do it no guesses on anything.

Or any repair shop or other could do the same for less money. Figure $200, to lift the car up, remove the fill plug, remove the drain plug, after fluid drains out, install drain plug, fill diff with fluid, ($20.00), install fill plug with new $2.00 gasket.

$200. for that...

My local junkyard will take used oil for free, they use the old oil to heat the shop in the Winter time.

Google Search

 

Remove the upper/fill hole first. Imagine draining it and finding out the fill hole is stuck

 

Just keep in mind that, based on numerous reports around here and on other Subaru forums, choosing "any repair shop" to service the front diff could quite easily land you with gear oil in your CVT. Then there's the question of what they decide to do when (or if) they realize they've messed up. If you're lucky they might drain the CVT and fill it with some aftermarket fluid.

 

Any 75w-90 gear oil will be fine but like others have mentioned be extra careful about the front differential to use the right fill plug and if you're going to DIY make sure you know whether your resource is talking about a TR580 or TR690 and which one you have. In the 2017 model year the 6 cylinder 3.6 has a TR690 and the 4 cylinder 2.5 has a TR580.

Valvoline FlexFill and Amsoil Severe Gear use flexible pouches instead of the standard bottle and you might find that convenient.

The video below is NOT a subaru but just to show the flexible pouches.

 

It is a fairly simple job and there is a write up description on the forum here with pictures Differential oil change: 2017 2.5 (TR580) front and... I even referred back to it when I did my 2019 Forester's first drain and fill of the differentials in May of this year as it was quite similar. I used Lucas 75W90 Synthetic Gear Oil for both and also 10 dollar hand pump worked well. I concur with making sure thee fill plugs are off before you take the drain plugs off. I also, although some may say this is not safe, drove my Outback and my Forester up on four equal ramps to do this job so it was equally level, its worked well for the three times I have donee the job.

 

I'm at 150k on my 17 3.6. I did front/rear diffs at 25k ish with Amsoil and again at about 125k. First drain/fill was to remove wear metals. The rear diff Amsoil looked similar to new while the front locker with Amsoil clearly showed more wear. This is looks only so not scientific at all. Observation only. Then I posted and read a round and learned the Subaru has a bias toward the front diff so it gets increased wear/tear. Makes sense off my observations.

Second time around 125k I used 75/90 Valvoline in the squeeze bags; what a great design and easy to use. I'll do mine again at 175k, likely Valvoline and then let it ride for the remainder of my vehicle's life. Likely to be 225k.

 

I'm at 150k on my 17 3.6. I did front/rear diffs at 25k ish with Amsoil and again at about 125k. First drain/fill was to remove wear metals. The rear diff Amsoil looked similar to new while the front locker with Amsoil clearly showed more wear. This is looks only so not scientific at all. Observation only. Then I posted and read a round and learned the Subaru has a bias toward the front diff so it gets increased wear/tear. Makes sense off my observations.

Second time around 125k I used 75/90 Valvoline in the squeeze bags; what a great design and easy to use. I'll do mine again at 175k, likely Valvoline and then let it ride for the remainder of my vehicle's life. Likely to be 225k.

Amsoil comes in the squeeze bags as well. Any good synthetic diff oil at the proper viscosity will work fine.

 

As folks said, I think there was a recent post re: a shop draining CVT then filling with 75W 90 gear oil which blew the tranny.

In any case, you can find DIY instructions on youtube / here, with required tools such as torx 70(?) for the front drain. I DIY every 3 year or so (with M1 75W 90) and taking the undertray is the most painful / time consumming item.

If you are going to drive another 80k miles or so and not a DIYer, I would just ask a shop to do this HOWEVER absolutely make sure they don't drain CVT fluids (e.g., CVT drain pulg is clearly visible whereas front diff plug - TORX70 - is above the undertray). If a shop can do both for $200 USD, that would be a great price for me.