Changing Yamaha Jet Boat Pump (Duct Housing) Bearings and Switching to Oil Bath Lubrication

[bronze_10]

I am at 800 hours and counting on the original pumps.

Are u doing the oil bath or typical grease? My boat is an 08 and never been looked at!

 

[14SX190]

Does anyone here offer pump bearing rebuild?
My boat has the marbles sound and new to me.

 

[ross l]

I got the intermittent loose marble noise and used this tread to learn how to replace the bearings and switch to an oil bath. Thank you for the great info. There was just a couple drops of water in the cone. Here is what that did to the rear bearing. Notice the corrosion on the outside of the outer race and outside of the inner, including the rust spot. I cleaned it up to see if I could notice a noise while spinning it in my hand. There is some chatter when spinning it manually but not much. I guess it gets amplified in the powertrain. I tried to pass it off to the kids as a fidget spinner. They weren't having it.

 

[14SX190]

I got the intermittent loose marble noise and used this tread to learn how to replace the bearings and switch to an oil bath. Thank you for the great info. There was just a couple drops of water in the cone. Here is what that did to the rear bearing. Notice the corrosion on the outside of the outer race and outside of the inner, including the rust spot. I cleaned it up to see if I could notice a noise while spinning it in my hand. There is some chatter when spinning it manually but not much. I guess it gets amplified in the powertrain. I tried to pass it off to the kids as a fidget spinner. They weren't having it.
View attachment 123180

My bearing had same markings on outer race.

 

[FLJetBoater]

At the end of May I checked the cone on my port side pump and found a teaspoon of water inside with the grease. This brought on the debate of should I change the bearing in advance of the Bimini crossing or leave them as is and risk a failure on the trip. I probably would have been fine but I decided to cautiously move through the process of replacing the bearings. I very much appreciate the advice of @Murf'n'surf, @Big Shasta, @swatski, @KXCam22 and everyone else who has posted about these bearings.

This is what my water compromised grease looked like. (All pictures in this post are thumbnails, click them to enlarge)

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For years I had mistakenly believed that the rear end of the shaft was supported by the single bearing seen in the first photo above. Through this process I learned that there is a second bearing at the front of the duct housing that we have no way of seeing or packing and is likely to be in worse condition. I believe that the water in my port cone had seeped in through the aged seals at the front of the duct housing and made its way back to the cone. All of my bearings looked ok but the front bearing on the port side had the most discoloration followed by the rear bearing on the port side. The starboard side had not leaked and it's bearings looked new.

In the picture below the top bearings are from the starboard side which had minimal or no water intrusion. The middle bearings are from port where I found water. The bottom bearings are from the new WSM kit.

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I decided to switch to using 70 cc of Amsoil marine gear oil in each housing instead of grease. This fills the housing and cone combination to 54% with oil. I decided on this oil due to it's ability to perform the same with 10% water contamination as when new. I decided upon oil over grease so that I can change it. With grease I could not do anything for the front bearing in the duct housing. @KXCam22 has a long term review of switching to an oil bath in this thread https://jetboaters.net/threads/pump-cone-oil-bath-mod-long-term-results.9521/.

I have had my boat since approximately 32 hours on the engines. Until this change there was always a noticeable noise from the pumps when the engines were running. After this change I found that the jets were silent. Initially I was concerned that I might have reinstalled them incorrectly. I believe that the factory bearings had play in them that was sufficient to allow the impeller to lightly rub the housing at some points of it's rotation. I also believe that play in the bearings contributed to the large amount of stuff that has gotten stuck in my pumps as well as the play may have been caused by stuff getting stuck in the pumps.

I ordered two $34 WSM 003-627 pump repair kits from @PartsPak.com. I also needed a $16 impeller shaft holder tool. Then I bought a series of PVC couplers and a pipe from Lowes to use as assembly tools. I took the bearings into the store and picked out couplers or pipe to fit the inner and outer race of each bearing and the seals. You need a length of pipe for the inner race of the front bearing as you will be pushing it some distance onto the shaft. I bought a 4' piece and cut a short piece to use. I was glad to have the extra because I pushed the bearing too far onto the shaft and had to back it off.

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I drilled an arbor into my work bench which eased many of the processes. When I finished I reinstalled the top section that I had hole sawed out.

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Initially I thought that I could replacing the bearings with the impellers on the shaft. I soon learned that the shafts press out of the housings from front to back so the impellers have to come off. These were the tool options that I had for removing the impellers along with a 1/2" cordless impact. The 1 & 1/16th wrench worked well. I preferred the Craftsman Pass Through Socket but the ratchet failed while removing the second impeller. I will take it back and exchange it.

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I filled the impeller collars with PB Blaster and left them soaking overnight.

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This was my preferred method of impeller removal. I was able to remove one this way. I ended up seeking a vice and and a second wrench added to the 1 1/16th as a cheater to free the second impeller. It is possible that the failure of the craftsman ratchet is the reason that the impact did not free the second impeller.

View attachment 40971

I borrowed a press at a nearby transmission shop to press the shafts with bearings attached front to back out of the housing then press the the shaft back to front out of the bearings. Then I took the shafts home, cleaned them and placed them in a freezer overnight.

Then I began following the reassembly process as documented in the attached Pump Assembly.pdf file which I believe to have been created by Fercho on GreenHulk Pump Assembly . Thank you Fercho!

I used grease when I installed the bearing and seals but I did not pack the bearings.

I experimented with this press free method of installing the bearings Pump bearing install tips. . I was able to to install the bearings on the shaft without a press. I put the shaft and bearing assembly back into the freezer for less than four hours and placed the housing outside in the sun. I might have been able to get them together if I had left them in the freezer longer used a bigger hammer or hit more rapidly but I decided to go borrow the press again about a 1/4 short of completing the assembly without it.

These are shafts with the bearings and spacers reinstalled. You can see that there are bearings on the front and back of the spacer.

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You can see the new rear bearing installed in this photo

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And the washer on top of the seals in this one

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I measured and found that the duct housing held 70cc of oil while the cone held 60cc. I decided that a little more than 50% oil fill was a good place to start. With the shaft through my workbench and the housing vertical it was easy to fill the housing then install the cone to seal the oil inside. I can easily repeat this to inspect or change the oil.

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From here I reinstalled the impellers and and reinstalled the pumps using the correct lubricant or sealant at each step. I also lubricated all of the accessible moving parts in the steering and reverse bucket mechanisms.

After reassembly we made a couple of days of long runs on the lake to test her out before going to Bimini. So far everything is working great. I will pull the pumps and check the oil for contamination this fall.

@Bruce These attachments for the pump assembly PDF and some of the pictures aren't loading. Would you be able to reattach them?

 

[FLJetBoater]

This is what it looked like in 2014 before water incursion.

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And in 2016

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I'm getting ready to push the bearings onto the shaft and grease them. my manual calls for "marine grease A" which is identified as "water resistant grease" (yamaha marine grease A) in the front of the manual, on the bearings, o-rings and oil seals. The inside of the spacer and the inside of the cone call for "yamalube marine grease or equivalent".

It seems like most people recommend using a Yamaha EPNOC grease in the cone. Looks like boats.net and other sites have it. Would I just use that everywhere that grease wherever it is called for in the pump assembly in replacement of the yamalube marine grease? Bearings, spacer, seals, cone, etc?

 

[Cobra Jet Steering LLC]

You may want to try a combination of the grease and gear oil, I am amazed at how well that works.
When I was replacing my intermediate bearings at 650 hours one of my pumps was not spinning freely, one was fine but the one that seemed to have a bit of resistance concerned me so I tried the gear oil in with the grease the resistance went away immediately just spinning the pump and holding the drive shaft, I went ahead and ordered a complete bearing kit and I still have that kit sitting on a shelf.
The pump now has 860 hours with all the original bearings and seals still working fine. All I can say is I am a believer I will add gear lube to my grease on all my new pumps and intermediate bearings as part of my ritual before ever putting them in the water just like the never seize on the plugs, dielectric grease on the plug boots and the white lithium grease on the engine and clamps and wiring connectors, redesigning the intake grates and a few other tricks like redesigning the bolts of the engine cover for easy access.

 

[FLJetBoater]

You may want to try a combination of the grease and gear oil, I am amazed at how well that works.
When I was replacing my intermediate bearings at 650 hours one of my pumps was not spinning freely, one was fine but the one that seemed to have a bit of resistance concerned me so I tried the gear oil in with the grease the resistance went away immediately just spinning the pump and holding the drive shaft, I went ahead and ordered a complete bearing kit and I still have that kit sitting on a shelf.
The pump now has 860 hours with all the original bearings and seals still working fine. All I can say is I am a believer I will add gear lube to my grease on all my new pumps and intermediate bearings as part of my ritual before ever putting them in the water just like the never seize on the plugs, dielectric grease on the plug boots and the white lithium grease on the engine and clamps and wiring connectors, redesigning the intake grates and a few other tricks like redesigning the bolts of the engine cover for easy access.

Interesting....how much gear oil should I add? And into the EPNOC grease?

 

[Cobra Jet Steering LLC]

20 -30percent oil mostly grease I just added it to the existing grease also even with the new O ring on the cone I also backed that up with a small coating of high heat orangs silicon gasket cement jus a slight amount to be sure the O ring does not leak because they have a bad habit of doing that.

 

[Bruce]

@FLJetBoater, I packed the bearings with marine grease when assembling then filled the housing with gear oil. That is working well five summers later. I do top up the oil most years.

I am uncertain as to what happened to the attachments. The assembly PDF can be downloaded from the original source Pump Assembly . I suggest reviewing it before assembling yours.

 

[FLJetBoater]

and a few other tricks like redesigning the bolts of the engine cover for easy access.

I'm actually planning to do this with the electrical box in my boat. Not that I hope to need regular access to it, but you cannot access it without removing the cleanout tray and a helper to hold the bolts. The top bolts don't even come all the way out I'm not even sure how you could ever replace them. They're blocked by the lip of theI'm wondering if throwing some 5200 over top of the bolt heads, or some other sort of epoxy on the bolt heads to bond them to the fiberglass would be a good idea. There's not much torque on them, they're just used to attach the electrical box to the back wall of the engine compartment via a lock nut on the inside.

@FLJetBoater, I packed the bearings with marine grease when assembling then filled the housing with gear oil. That is working well five summers later. I do top up the oil most years.

I am uncertain as to what happened to the attachments. The assembly PDF can be downloaded from the original source Pump Assembly . I suggest reviewing it before assembling yours.

Thanks @Bruce i went through and reviewed it. It seems that the new shafts are made in a way that it is very easy to see where the bearings go. There are stops where the shaft thickens for both the inner and outer bearings so when you press them on they go exactly as far as they should.

I still don’t quite understand the orientation of the seals. This PDF may be a bit older and not perfectly aligned to my boat. I have both seals. Both have one flat side and one side with rubber. The rubber sides fit together perfectly to form what appears to be one large seal. This seems like the only way that makes sense to insert them. I’ll post some pictures of both the shaft and the seals when I get home later. The service manual and parts diagram have very poor images of what the proper orientation should be.

 

[Cobra Jet Steering LLC]

@FLJetBoater


Sorry different engine cover bolts I am referring to the plastic cover on top of the engine itself.

 

[FLJetBoater]

@FLJetBoater

View attachment 136284
Sorry different engine cover bolts I am referring to the plastic cover on top of the engine itself.

Yeah I figured. I’m just saying.....there are a few other oddly designed things too. Also most people would tend to lean on those engine covers when reaching to the back but it doesn’t seem that they should be supporting much if any weight at all.

 

[mrcleanr6]

When you make grease for the bearings you mix your gear oil with the #2 grease. You want to make it so at room temp the grease barely doesnt run on a vertical surface or mixing stick. You dont want it to drip off a stick but barely hang on. This way when it heats up just a little it will turn more liquid and run down the inside of the cone and keep the bearings lubed. This is what the epnoc grease does. Makes it easy to manage and pack into the cone and bearings bit turns to a thick oil bath while in use. If you put regular grease in there it will just sling out of the bearings and the bearings will run dry

 

[FLJetBoater]

Here’s a picture of the 2 seals and how I believe they fit together. It makes sense to me, this way you have 1 solid ring against the duct housing and 1 solid ring against the spacer. They also just fit nicely together this way.

also, the spacer fits nicely on to the end of the shaft as it exists the housing. The parts diagram has the o-ring on the outside of the spacer between the impeller and spacer. That makes little sense to me. There is actually a groove on the inside of the spacer that looks like it’s made for that o-ring. The service manual doesn’t even have the o-ring so ?‍

 

[swatski]

This is from my old 190 shop manual if that helps - below, I can not find my 240 after the move, but the pump assembly should. be the same.


if you want the manual, I have the AR/SX190 pdf, most things are the same. pm me your email.

 

[swatski]

 

[swatski]

Here’s a picture of the 2 seals and how I believe they fit together. It makes sense to me, this way you have 1 solid ring against the duct housing and 1 solid ring against the spacer. They also just fit nicely together this way.

also, the spacer fits nicely on to the end of the shaft as it exists the housing. The parts diagram has the o-ring on the outside of the spacer between the impeller and spacer. That makes little sense to me. There is actually a groove on the inside of the spacer that looks like it’s made for that o-ring. The service manual doesn’t even have the o-ring so ?‍

The above is the 2012 manual, I just checked in the 2016 - and it looks the same:

 

[FLJetBoater]

The above is the 2012 manual, I just check in the 2016 - looks the same:
View attachment 136358

Thanks so much. Those diagrams are way, way better than my 2014 one (at least the online version.) I definitely would have put the seals in the wrong way and the o-ring on this diagram is in the spot that makes sense. The parts diagram has it between the spacer and impeller.

 

[FLJetBoater]

The x x x x on the bearing, is that an actual marking or the writing? I bought the sbt bearing rebuild pack before (was about same price as oem bearings) but they don’t have those marks on them