Lower Unit Shaft Grease Fitting

[Gettin Right]

Doing some routine maintenance, and while greasing all fittings having trouble getting grease into the housing around the shaft. I removed the grease fitting and cleaned out the old grease and reinstalled. It seems like the grease has hardened in the housing and won't allow new grease to force out old grease. Does anyone have any solutions on how to remove old grease? The motor is a 2003 Yamaha 250 2-stroke HPDI.

[boats.net]

You would have to remove bearing carrier and clean old grease out.

[robert graham]

Wonder if a heat gun or hair dryer directed on there might loosen/melt the old grease?...maybe worth a try?

[Gettin Right]

Do you think steam would be a good idea? Steam is water,but if its just going through grease channels would there be any harm?Iif it works I could just send a bunch of new grease in to get out remaining moisture. Any thoughts?

[robert graham]

I wouldn't use steam, since it's just water and not so good for bearings and gears. Maybe remove the zerk fitting, apply heat for a good while with the heat gun or hair dryer, probe into grease passage with a fine wire, then replace zerk and try to pump in some grease. There is also a grease injection needle(Autozone) that you can slip the needle under the shaft seal and inject grease that way...but I'd do it carefully so not to nick or damage that seal. Might be easier than removal of bearing carrier.

[Tucker]

The reason this happened is because someone used automotive grease and it caked up. Lot of guys make this mistake. Just because it says waterproof doesn't mean you can use it underwater. That OMC blue grease or Mercury 2-4C is the best stuff to use. Gonna be hard pressed to heat that up with a heat gun, lot of metal between the gun and the caked up grease. Think robert has the right idea, stick a stiff wire in the grease hole to loosen up the old stuff. Hopefully the new grease will "liquify" the caked up stuff.

[Gettin Right]

Going to try to clean it out tomorrow, Ill let all know what happens.

[Gettin Right]

Ok no luck, what is my next step? Took the grease fitting off cleaned out but I can not get grease into housing. When looking into hole without grease fitting in it does not look like there is any channel for grease to go. What purpose does this grease fitting serve?

[seahorse5]

The grease fitting inside the gearcase is no big thing. It is to keep a salt buildup from freezing the propshaft bearing carrier in place. It also can help in extreme cases where salt buildup can expand and crack the aft part of the case, as old Mercurys had that problem.

[robert graham]

Just an idea...maybe rotate prop shaft while attempting to pump the grease?

[Tucker]

The grease fitting inside the gearcase is no big thing. It is to keep a salt buildup from freezing the propshaft bearing carrier in place. It also can help in extreme cases where salt buildup can expand and crack the aft part of the case, as old Mercurys had that problem.

So the grease is extruded around the outside of the brg carrier?

[BaileysBoat]

So the grease is extruded around the outside of the brg carrier?

Exactly. Keeps it from seizing in the lower unit.

[TownsendsFJR1300]

If you want to try this, it may work, may not.

Remove the grease fitting, wipe any grease anyway from the area. Get some brake cleaner and spray it in the hole. It should break up the old grease. An air compressor should help as well.

IF IT DOES OPEN UP, you need to re-grease that bearing several times to make sure you get ALL the brake cleaner out...

[99yam40]

Only way to do it right is to remove bearing carrier and clean properly

[Gettin Right]

I guess I would need a puller to remove the bearing housing. Would I be getting into gears and seals on the back of bearing housing? Is this something that is that the average shade tree mechanic can do? Sounds easy enough.