Dealer Prices for service I had done.

[Owen Lucas]

Honda wants $135 to change the engine and cabin air filters. Did them myself as part of the B12 maintenance.

 

[JTK]

The front diffs are built into the CVTs on Subarus, but do hold their own separate gear oil.

Where I recall the front differential fill and drain plugs on my 2012 Legacy and 2016 Forester, it was kind of a pain in the stones for the driveway hammer mechanic like myself.

The rear diffs are super easy to DIY.

 

[Leo99]

The diff service is WAY too pricey. Easier than an oil change. My Subaru dealer put in garbage rear diff juice and i had to drain a month later. Heard the rear diff howling on a highway trip. It was Mobil 80w90HD junk.
Put in supertech 75w90 synthetic and all was well.

Just finished my Rav4 rear diff and transfer case. The rear diff was very easy. The transfer case is a little tricky. There is very little room to tighten the fill plug. I used a 10 mm wrench on a 10 mm hex socket. Since you can't fit in a torque wrench they mark the plug and case with a mark that you line up to show it's tight enough.

Biggest problem was my gear fluid pump broke and I got covered in fluid and I had to run out to buy a new one.