Which engine drive package do you have?
Mercruiser, OMC, Volvo, All have GM 4cyl engines.....
Ok, what we need to do first is determine the area of the issue. Meaning the drive or the steering cable or helm areas.
We will need to disconnect the steering cable at the engine. There is a link arm going from the end of the steering cable to the steering arm of the drive. Locate this arm and remove the connection to the steering cable end.
Now go outside and move the drive back and forth to test for any resistance. A 2000 mercruiser may or may not have a grease fitting on the top and bottom steering pins located on the outside of the boat, but they are easy to find when looking for them (Outside The Boat). Likely you won't have the grease fittings, this was about the time they stopped putting them on the drives.
Now turn the steering wheel back and forth, we should be able to turn the steering wheel with one or two fingers, understanding that we are not turning the drive only moving the cable. If this is a little stiff, the steering will be really stiff when under power.
The only other area we need to look at is the torque tab on the rear of the drive. Be sure it is near straight.
I ran out for breakfast with my wife, only day we have off together....
The steering cable end at the engine should look like, well, a rod with a bolt hole through it coming out of a tube. This bolt hole is where the link arm attaches. Remove it here.
To answer your question, if the rod end of the cable at the engine looks to be dragging through the tube, YES, grease it first, but likely the cable will need to be removed from the tube to clean and lubricate throughly....This is the leading issue we have with this unit. The cable solid end dragging through the tube.
There will be no grease fitting on this tube or cable, too much grease will lock the cable up so one is not mounted there.
The grease fitting that might be on your unit would be outside and on the top and bottom steering pins.