The rear oil seal is leaking and the rear housing is full of (ATF) fluid.
Where can I find new oil seal?
I have a part diagram of this trans but no part numbers
Somebody can help me out?

This guy is "all knowing" for Merc Trans stuff.....

KC Marine | MercTrans TR/TRS Repair, Design, Modification Experts

Great company.

OT.. If you ever need a couple spares I have two extremely low hour ones that even look new for sale.

You can get that seal anywhere off the internet. Just get the number off of it and google it. I have them out at my shop and can get the number for you next time I'm there if needed. Be careful when you remove the tail housing, there is a very small o-ring between there about as big around as a pencil. Also there is a washer that goes on over the splined output shaft for the spring on the outdrive input yoke shaft to push against. An o-ring holds the washer up in place on the shaft. If you leave that washer off that spring will tear the seal up. That may be what has happened now to leak out that much fluid. Also polish the shaft with emery cloth where the seal rides.

I can tell you the Mercury part number is 90-8M0101807. However it is no longer available from Mercury. Knock out the seal and the actual seal number is printed on the side. You can easily find them under that number on the internet.

That seal number is 10050. You can get them anywhere. https://intechbearing.com/products/1...il-grease-seal

PERFECT, thank you ! that's the part number I was looking for
Seal that was mounted, did had metric dimensions and broken

Someone also knows the exact SKF part number (or exact dimensions) for the bearing?

If that seal was destroyed than it must have been missing the washer that goes on the splined output shaft for the spring on the outdrive to press against and keep it away from the seal. Also a o-ring goes on after the washer to hold it in place. Washer and o-ring are parts 105 and 106 in this diagram. https://www.perfprotech.com/mercury-.../330?model=693

I have those bearings as well at my shop. I can get you the part number when out there later this week. Check back here in a few days.

Part number of that bearing is NDH 3305. Never seen them in SKF.