Thanks for your thoughts,guys.
I am gonna clean it well and dry fit to see if the main seal makes a good contact.
There was no oil seeping form the old one,so I hope that a new one will be enough without changing the sprocket.
Now,I have another question.Did any of you drop the front subframe to change the upper oil pan gasket?
In the DIY I see that there was a some sort of paper or alike material gasket,but I ordered and there's one steel gasket installed now.
Should I just clean it all well and use some gasket maker.It would be a nightmare too to try reaching all the perimeter without lowering the subframe that much.

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e53 '00 4.4i Oxford Green II Freshly rebuilt tranny(2nd one) and transfer case/front shaft
e70 '08 3.0si Sapphire Black cinnamon leather 7 seats
e61 '06 530XI Sports Touring Silver - SOLD