What was the diagnostic code? Doing a timing belt change at 83k without any signs of early wear is ridiculous. Look at the axle boots and see if they've cracked and sprayed grease everywhere. If not, they're fine. The front passenger side is generally the one that goes.
I'd recommend finding a subaru specific shop near you that is NOT a dealer.
I'd recommend finding a subaru specific shop near you that is NOT a dealer.