I am getting ready to change my rear main seal(motor pulled, yay). I bought a new one before realizing I already had one. The thing is that it's 16 years old but has been sealed in the bag the whole time. I pulled it out and the rubber feels as soft as the new seal I bought. Would you use it or just go with the new one? Also the instructions for the old seal say to soak it in motor oil before installing, I thought I just needed to smear some grease on it.