Rudder Post Lubrication

Gin

Well-known member
Joined
Dec 12, 2012
Messages
874
Fluid Motion Model
R-31 S
Vessel Name
Echo II (2019)
I've seen posts recommending that the rudder post be lubricated annually through the zerk fitting with about two pumps of a grease gun. I assume that is two pumps with a large grease gun that holds a 14 oz or so cartridge.

If so, does anyone know how that would translate for a small grease gun that holds a 3 oz cartridge -- which is what I have. Seems logical enough that the amount of grease the small gun puts out per pump would be less than the larger gun, but how much less? Any ideas?

Gini
 
Gini, The rudder post doesn't require much grease. The rudder post has three o-rings on it sealing the grease in the housing and the water out. The grease is to lubricate the bushings the rudder post rides on. Adding a couple of pumps yearly is just to freshen the old grease. Adding 1 pump from the grease gun could be adding .5 grams to 3.0 grams depending on the grease gun. Lever grease guns normally pump more grease than hand grip grease guns.

In this use ( greasing rudder post ) I use a grease gun that pumps approximately 1.5 grams (14 oz) ( how do I know this? ) I worked in the QC reliability department at a petrochemical refinery. Greasing equipment, over greasing or under greasing can damage machinery, plus there are always the bean counters " Why are we using so much grease?" We used the same grease guns throughout the plant base on the fact that we knew they discharged approximately 1.5 grams per pump.

I don't know if 2 pumps is the required amount for the rudder post. It has worked for me, and seems right. There is no grease leaking out and the rudder turns freely. If your grease gun doesn't put out as much as 1.5 grams per pump I would not worry about it. I would be more concerned with over greasing than under greasing in this application.
 
BB marine":56mdrvtv said:
approximately 1.5 grams (14 oz)

I don't know much if anything about the topic, but 14 oz = 396.9 grams. Conversely, 1.5 grams = 0.05 ounce. Typo?

Cheers,

Bruce
 
(14 oz cartridge grease gun) This is how It should have been written. Thank you Bruce, I can see how that doesn't make sense.
 
Brian, thanks for the info. I was hoping you might weigh in on my question, since one of the “two pumps” posts that I saw was yours. Your technical knowledge is always a help. My hunch is that my small grease gun puts out less than 1.5 grams. But to be sure, I will measure the output when I get a chance.

I realize the recommendation on the amount of grease to add was a ballpark one. I’m used to doing wheel bearings on a trailer, where the squeeze out lets you know when you have enough in. I don’t want to blow out any seals on the rudder post, although perhaps that’s not easy to do. I’d rather not find out the hard way. So I’ll try to be slightly scientific and see what my pump puts out compared to the 1.5 grams of yours, and I will top off annually accordingly.

Thanks again!
Gini
 
What kind of grease should be used? I bought the boat used so I don’t know what grease is in there now, although it’s less than two years old so likely just has factory grease.


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I use the same green water resistant grease I use in the trailer wheel bearings
 
Any good marine grease can be used. I use Quicksilver 2-4 C.
 
I also use Quicksilver 2-4-C and generally add two pumps of my grease gun at the end of each season.
 
Gini, The rudder post doesn't require much grease. The rudder post has three o-rings on it sealing the grease in the housing and the water out. The grease is to lubricate the bushings the rudder post rides on. Adding a couple of pumps yearly is just to freshen the old grease. Adding 1 pump from the grease gun could be adding .5 grams to 3.0 grams depending on the grease gun. Lever grease guns normally pump more grease than hand grip grease guns.

In this use ( greasing rudder post ) I use a grease gun that pumps approximately 1.5 grams (14 oz) ( how do I know this? ) I worked in the QC reliability department at a petrochemical refinery. Greasing equipment, over greasing or under greasing can damage machinery, plus there are always the bean counters " Why are we using so much grease?" We used the same grease guns throughout the plant base on the fact that we knew they discharged approximately 1.5 grams per pump.

I don't know if 2 pumps is the required amount for the rudder post. It has worked for me, and seems right. There is no grease leaking out and the rudder turns freely. If your grease gun doesn't put out as much as 1.5 grams per pump I would not worry about it. I would be more concerned with over greasing than under greasing in this application.
 
Brian,

We have a 2014 R29 and this is the second season for our ownership. I tried to grease the rudder stock and could not get it to accept any grease. I removed the zerk fitting and verified the fitting was not at fault. I was using a small grease gun and planned to go at it again today with a larger gun. Looks like I should remove the rudder arm to hydraulic cylinder bolt and check the rudder lever turning resistance.

After reading that there are three O-rings separating salt water from the grease, would the very high pressure that a grease gun can deliver potentially extrude those O-rings out the bottom of the rudder stock bearing? Is the unit designed to have excess grease come out under the rudder lever on the top of the unit? Does the steering wheel give rudder turning resistance feedback; can I tell if rudder bearing turning resistance is increasing from the feel of the steering wheel?

Thanks for all of your support to the community,

Dave
M/V Ruby Slipper
 
If you were using a pistol grip grease gun (As I do because of space limitations) the output pressure is much lower than a lever 14 OZ gun. If you couldn't get it to flow after checking the zerk, I would suppose that the cavity between the seals is overfilled. If you take the zerk back out and check with a pick to be sure the threaded hole is not plugged, I would run the helm limit to limit a few times and see if grease comes out. This might indicate it was overfilled. The goal is just to put some fresh grease in the bushings, not jam the grease against the seals.
I am with Brian and have been putting two pumps with a pistol gun before storage for several years and have not have a problem. I do not have an autopilot.
If it is overfilled, I would just leave it alone and try again in a year. I would not try a bigger grease gun because of the seals.
 
If you were using a pistol grip grease gun (As I do because of space limitations) the output pressure is much lower than a lever 14 OZ gun. If you couldn't get it to flow after checking the zerk, I would suppose that the cavity between the seals is overfilled. If you take the zerk back out and check with a pick to be sure the threaded hole is not plugged, I would run the helm limit to limit a few times and see if grease comes out. This might indicate it was overfilled. The goal is just to put some fresh grease in the bushings, not jam the grease against the seals.
I am with Brian and have been putting two pumps with a pistol gun before storage for several years and have not have a problem. I do not have an autopilot.
If it is overfilled, I would just leave it alone and try again in a year. I would not try a bigger grease gun because of the seals.
 
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