Reply To: Neptune OB51 lower unit lubrication

[Buccaneer]

If the grease is ancient, you may want to disassemble the gear case to clean
out the old grease first, as sometimes old grease gets hard and pretty crusty.
Good to inspect bearing, gears, etc., anyway.
I use tubes of cornhead grease in my grease gun. I make up a alemite fitting
to screw into the bottom gearcase hole, and pump in grease until it comes
out the vent hole further up. Normally this should be ample to lubricate
the driveshaft bearing / bushing as well.
Maybe someone with your particular model of Neptune will pipe in.

Prepare to be boarded!