Hi Bjarte,
There is a way, but it isn’t easy. You need to drop the pan and loosen the crank to take the compression off the seal. You’ll need a tool that looks like a long fish hook. You may have to find an old time mechanic who has one from the days when rope seals were the norm.
Use a soft, flexible rod, like heavy gage copper wire, to follow the seal groove and push the old seal out. Pass the fish hook tool through the groove and hook the end portion of the new seal on the hook then pull the hook and seal back through the groove. The seal will be a bit too long and have to be cut with a sharp razor. Cut it a 1/16 inch proud of the journal surface so that the lower journal cap will compress the seal and swell it in the groove. That makes the seal tighter. You then have to torque all the journal caps and reinstall the pan.
To my knowledge, there is no other modern rubber type seal that works. However, I have heard that a Mercedes rubber seal will work, but know nothing else about it.
Hope this helps,
Ralph
