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Help - overfilled/overgreased intermediate bearing housing

stevenk2

Jet Boat Addict
Messages
135
Reaction score
24
Points
107
Boat Make
Yamaha
Year
2019
Boat Model
AR
Boat Length
19
Have a 2019 AR195, was doing a bit of prepwork getting ready for the spring season, and like an idiot overfilled the intermediate bearing housing with marine grease. My grease gun is too apparently too efficient, and I wasn't watching close enough - by the time I realized, it was too late, evidenced by a pile of blue-green grease under the housing. :banghead: I've searched tons of posts, everything from "no worries, you just need to clean up the mess with the excess grease", to "you need to take it into the dealer and have the bearing replaced immediately". I mopped up all of the excess grease, so it's clean in the hull at least, but my bigger concern is I go to run it this season and find that I've ruined the jetdrive and/or left gaps in the bearing seal where water can get in.

I would say that I greased the thing prior to running it last season (filled perfectly, no pile of grease that time), and I had it out in July at Lake Powell and in September at Lake Havasu, and noticed that on the first runs each time, the boat seemed to bog for a bit (a couple of mins) each time before returning to full performance. I do check the engine bay regularly when we go out, and did not notice any water intrusion, nor was the bilge running any more than it normally does. Since we don't use the boat much other than for those two trips each year, I attributed the performance lag to old gas sitting in the system for a few months. The boat is garaged, so it doesn't sit outside and wick a bunch of moisture from outside into the system either, plus I add stabilizer when it's going to be sitting idle in the garage for a period of time.

Is this something I can just continue to run and not be worried about, or did I ruin the intermediate bearing and need to have it replaced ASAP before I head out with it this spring? I'm reasonably handy with tools and have done work on the boat and my other toys before - if the bearing does need to come out and be replaced, is it a job that I could handle myself? Or should I just take it into my Yamaha dealer and have them take care of it?

Also, if it helps to know, the boat is pretty lightly used (56 hours) and has only seen fresh water; additionally, we don't leave it in the water and always trailer up at the end of the day. The engine bay looks brand new, with no corrosion or other indications of wear/damage anywhere (again, I inspect the thing very regularly, both in and out of the water).
 
I would do a test run when able on the water before you plan any trips out. Run it around at moderate speeds for a bit and see what happens! I don't know if it would bend the bearings or if it would squeeze out and it probably depends on how fast you pushed grease in. It's not like a balloon that just pops, it's squeezing through cracks. Too much too fast and it bends. So either you take apart to inspect or run it and find out for sure.
 
Thanks - if I take it out and run it, what specifically do I need to be watching for? Will it be pretty obvious that something is wrong? Also, can I run it on the trailer with a hose in my driveway to test, or is this something where I truly need to be on the lake before I'll be able to tell for sure?
 
Should be fine unless you used a pneumatic grease gun set on high pressure. Clean it up and go for a run which will likely sling out a little more. No water intrusion...no problemo.
 
Good deal then - that would be a huge relief. My heart just sunk when I saw that pile of grease underneath after I was done last night. I'll keep a close eye on it when I put in for the first time this season. Definitely wasn't a high-pressure gun, just one of those little mini 3 oz. hand-operated guys that fits in the tight spaces back in the engine bay. I'll definitely need to be more careful next time I go to grease it though. I think the one thing I have working in my favor is the age of the bearing - I would think that it would be less apt to damage the fewer running hours on it. If I had 200 hours on the boat and the bearing/seals were more worn it might be a different story (not that you probs can't destroy the thing if it was brand new and were really trying).
 
Just seems like Yamaha would have made the process a bit more foolproof with that bearing - maybe have a small reservoir or something to fill with gear oil or grease where you could see and check the level a bit more easily. By the same token, I suppose I should have taken a bit more care as i was pumping it in.

Will having it on the hose in the driveway show evidence of water intrusion in the engine bay, or do I truly need to have it out on the water to be able to tell? I'm assuming that the water would come in as a result of the flow up through the intake grate and past the impeller, not via the cooling system, thus having it on the hose wouldn't really tell me anything.
 
Nope you have to fill the hull with enough water to see if it leaks out the driveshaft the design is as bad as the old blow out plugs you can not pump grease into that housing if it has no place for the excess pressure to exit and since they drilled through the rubber between the outside and the bearing assembly when you force grease in that can separate the parts. If the grease blows past the seals it may be ok but if it is pushed out the rubber on both sides it will leak . I had pictures I posted in some of those posts , the gear lube with the grease liquifies the grease lets it lube the parts and seals better and does not create pressure internally this shows how the parts have a hole through them to the grease fitting, so when the grease creates hydraulic pressure it separates the rubber part from the outer metal part thus opening it for water to enter the hull and the bearings
.1708390951211.jpeg1708391135565.jpeg
 
So basically the theory with the gear oil is that it dissolves all of the marine grease and replaces it, then the seals relax and can reseat? Or once the seals have been blown out by the grease, the only real way for them to reseat is to replace the bearing? Then only ever use gear lube to grease them going forward?
 
This has nothing to do with fixing the rubber mount or the seals after they have blown out from over greasing them, it has everything to do with avoiding that situation in the first place and making the grease in the housing more fluid so it lubes the parts better and does not get thrown to the side over time reducing it's contact and increasing the wear on the moving parts. If your seals around the shaft were leaking grease that is not as bad as if the rubber holding the bearings to the housing is where the grease came out. picture attached shows the rubber leaking not the seals
1708440805674.jpeg
 
That's pretty much what mine looked like after I overfilled it, though it was difficult to see exactly where the grease was coming out. I guess the only way to tell for sure is to get the boat in the water and run it and see if there's any water intrusion/leakage.
 
Pull the grease zerk and let out any excess pressure if there is any.. then go and put a tank of gas through it. Just keep an eye out to see if any water is leaking in there. Put a blue paper shop towel down underneath it to see if any water is coming in.
 
Thanks - just remove the zerk fitting at the top? Or is there another one down near the housing? Also, is the fitting at the top just a barbed connector going into the filler hose?
 
Thanks - just remove the zerk fitting at the top? Or is there another one down near the housing? Also, is the fitting at the top just a barbed connector going into the filler hose?
I’d remove the fitting at the bearing housing…
 
I change the fitting to a hose barb and add a hose to it , then fold it over and clamp it when I am not using it and it is the only fitting on the assembly and I make the hose long enough to access it so I don't need to get back behind the engine to put a little gear lube in , you can just unscrew the barb for access and then return it to the hole it goes in but I like the hose.
Then when you want your pump to last a long time remove the end cone and lower the front of the boat then inject some gear lube in the pump housing also , thus liquifying the grease and doing a better job of lubing the inner moving parts and the seals.
 
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