I posted this over on fastboatscanada.com:
I had a set of ride guide steering cables that were so siezed I really couldn't even drive my boat. It was to the point that I was almost unable to turn the wheel with one hand at a stand still. Unfortunately these are NLA from Merc. So as a last ditch effort I decided to take T-Rex's idea of a steering luber (
http://www.hydrostream.org/ArticleArchives/Luber.htm) and give it a try. In short, this concept uses a compressor to push a cleaning/lubricating agent through the cables.
First let me say, one thing I did differently is I made my system attach at the helm side of the cable. I did this because most of the crap and grease enters the cables from the motor side. There is no use trying to push it all the full length of the cable. So I took a 1/4 air fitting and through the use of a couple of plumbing fittings and 3' of high pressure 5/8" hose had a system that would work.
I first flushed the cables with some wd-40 mixed with acetone and goo-gone. The first cable took about 10 minutes for the mixture to push through. The second took about 4 hours of 100psi and alot of running the cable back and forth under pressure. When it finally broke free I found my problem... hardened grease, and lots of it. Apparently these systems are not supposed to ever be greased but rather lubricated with synthetic gear oil.
I used a full synthetic 10w-30 oil after the wd-40 mix to oil them back up.
A little trick is to pull the grease fitting to give all the grime somewhere to escape from.
As it sits now I can turn my steering system lock to lock with my pinky finger. I was pretty skeptical about this idea when I first got it but honestly it works like magic!