I've just purchased a snapper 30" RER and I'm loving this thing! Replaced many parts and just did my first mow yesterday. I see now that I have a bad seal under the flywheel as I had oil running down the side of the engine. I searched on parts tree and found a seal #3 but also see a bushing and seal #2 and I need guidance as to what I need! Do I need #2, #3, or both? I appreciate any advice.