I pulled my lower unit, A Volvo duo-prop to replace a leaky drive shaft bellows. The gimbal bearing was rusty and growled when I turned it so I pulled it and replaced as well. Now I cannot get my lower unit back on. The bearing is seated. I have checked that. This is my first go at this so any pointers would be appreciated. I can get it as far as the studs just touching the holes but no further.