Can I check the Lower Unit gears without disassembling the carrier? I have a 1990 260 Alpha. The upper unit ran low on lube after a water pump replacement, the quad seal is still in place. I still don't know how the lube disappeared, but anyways the upper unit gears are spalded along with the lower bearing fried. I have a gear/ seal kit with the setup tools for the upper unit but need some assurances that the lower unit is ok. I did not see metal when I drained the lube. It shifts ok also, static shift. I wasn't aware of the pressure / vacuum check until after the failure.