First off, if cable, REMOVE the steering rod that passes through the tile tube and clean it ALL out. I use old 12-gauge cleaning rods on a rod section in a power drill.
Then ADD a Steersman to permanently seal off the tube. Then ONLY use OMC/Bombardier "Triple Guard" waterproof, blue-colored, synthetic grease to lube the cable and zirk fitting. All OB makers make that same grease and it all comes out of the same factory, but the US-labeled brand will be 1/2 to 2/3rds the cost for the SAME product wearing a Jap OB label on it.
Without a Steerman - cable:
How it works:
Where to install:
If hydraulic ... there are some lube grease points you need to do to the steering arm of the motor, check your Owner's Manual, using the SAME grease as per above. Do NOT use any white lithium grease in saltwater!