Mercy 60/40 4 stroke squealing

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rotus623

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Just wondering if anyone else has had this issue. I believe it is coming from my jet lower bearings. Maybe the seals are going? What are some signs of lower bearing failure? Sounds like its getting worse too.
 
You might check to see if your impeller nut has backed of letting the impeller drop down rubbing the liner. I've seen them do that before and they do make a squealing noise.
I've heard of people having bearings go out and the impeller dropping, but the bearing I've seen go bad have just bound up without dropping but there are 2 or 3 different style of bearings over the years.
 
Lil' Blue Rude said:
You might check to see if your impeller nut has backed of letting the impeller drop down rubbing the liner. I've seen them do that before and they do make a squealing noise.
I've heard of people having bearings go out and the impeller dropping, but the bearing I've seen go bad have just bound up without dropping but there are 2 or 3 different style of bearings over the years.


Lil Blue, unfortunately you were correct!! Man you know your stuff. The impeller nut surely did back itself off and the impeller dropped. It cut some grooves into my liner for sure. The impeller is fine buy I may have to replace the liner.

Somehow the nut slipped past the stopper. I am going to order a new nut stop and will see how it holds up before trying to replace the liner. Maybe I should put some teflon tape on the threads?? Just wondering why it would have come loose on it's own.
 
If you bent the tabs up on your nut I can't see how it could slip unless the threads were stripped?
 
I bent em up, maybe not hard enough...........

The real answer about greasing the bearings is yes, and no. I bought the boat used and the P.O. did NOT EVER put grease into the bearing carrier. EVER......... The guy that owned it before him may have, but doubtful. Since I have owned it I certainly have. Never seen much water come out of it.

Anyways, got some new news. Anyone ever hear what an old rusty bearing sounds like? One that has pitted races or rust in it? I certainly have, as I have had trailer bearings that had set for years and they made a horrible noise when I pulled the trailer for the first time. I started the engine up and could hear something very similar, like a vibrating bearing, sounding a little bit like scraping. The noise was constant but changed its sound throughout. Kind of like something hopping around in a garbage disposal, but not as loud or harsh!!!! (I am overexaggerating, but you get the point!)

Anyways, I did the old screwdriver trick and it got louder down in the gearcase area than it was up near the powerhead. I do not believe it to be coming from the powerhead. This is a 4 stroke motor with no knocking, and that bottom bearing stays bathed in oil vs a 2 stroke.

This motor has had an intermittent "whirring" sound since I first got it. Sometimes it does it, sometimes it don't. Sounded like a serpentine belt slipping, but coming from down lower. Very annoying. I suspected lower bearings from day one.

In an attempt to further isolate the issue, I took the impeller off the driveshaft, and VOILA!! No more noise. Motor sounded as good as it ever has. So I am pretty confident that I have isolated it to the jet lower bearing(s). My next move is to pull the lower and get that carrier out. I have the service manual for it, but has anyone ever removed the carrier? My concern is that I will likely need a bearing press to get the old bearings out and new ones in. (Dad and I used to just use sockets to drive them in and out.)
 
I would give Brian @OBJ a call. Very helpful and may well save you some time doing it the wrong way first.
 
Yea Brian is always eager to help!! I did some serious research on their website and found out all I think I need to know to start out.

I got the jet foot off and spin the driveshaft. The bearing feels ratchetty, sounds gritty and has quite a bit of resistance. The upper snap ring is very rusty and is currently soaking in PB blasted so I can try and get it loose tomorrow. So far I am pretty certain that this bearing is shot and will need to be replaced. I will let you guys know how the bearing looks once I get it out and soak it in degreaser for a while. I sure hope my driveshaft isnt pitted where it contacts the bearing. Will update tomorrow night!!!
 
Unless you just want to do it for the learning experience, I would suggest that you send the shaft to OBJ and have them rebuild it. Last one I had rebuilt two years ago cost around $225 including shipping. Probably a little more now, but if you do it yourself I doubt that you will save more than $100 or so after buying new bearings and seals.
 
Well, not really the learning experience, but the timing and certainly $$ aspect. Just don't have any extra cash laying around, this second boat has just about broke me.

Anyways, I was looking on the OBJ site and the bearing in my lower is a 7305B. OBJ wants $60 for it, which is super expensive. I can get a brand new good bearing for $20-$30. Obviously the quality is of a concern. Are the bearings from OBJ possibly stainless steel? I am trying to figure out why the cost is so much more.
 
I can't say whether or not the OBJ bearings are made of SS. Never had one apart. I don't have a press to remove and replace the bearing carrier and I was leery of trying to do it without one.
 
Opened my pump up a couple years ago, thought I had the same problem, but mine ended up being the Teflon shaft collar was shot. went ahead and pulled the bearings anyway, it wasn't hard. I checked to see what bearings cost back then and it was crazy expensive. I do remember using my bearing numbers and checking Napa, they could get them at like 1/3 the cost. Mine where not sealed bearings like I thought, and I know their factory, I boat my boat brand new as a jet.

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dearl said:
Opened my pump up a couple years ago, thought I had the same problem, but mine ended up being the Teflon shaft collar was shot. went ahead and pulled the bearings anyway, it wasn't hard. I checked to see what bearings cost back then and it was crazy expensive. I do remember using my bearing numbers and checking Napa, they could get them at like 1/3 the cost. Mine where not sealed bearings like I thought, and I know their factory, I boat my boat brand new as a jet.

Thanks for the awesome input dearl! By teflon shaft collar are you talking about the shaft bearing thrust ring that goes onto the driveshaft? What jet unit and HP is that?

You are right, $60 for these bearings is quite expensive, especially if they arent sealed or anything special. So did you go with the napa bearings, or just re-install the used bearings? Thanks man!!

Oh, and did you have to remove the top snap ring to get the bearing housing out of the pump? I have a torch and heat gun.
 
rotus623 said:
dearl said:
Opened my pump up a couple years ago, thought I had the same problem, but mine ended up being the Teflon shaft collar was shot. went ahead and pulled the bearings anyway, it wasn't hard. I checked to see what bearings cost back then and it was crazy expensive. I do remember using my bearing numbers and checking Napa, they could get them at like 1/3 the cost. Mine where not sealed bearings like I thought, and I know their factory, I boat my boat brand new as a jet.

Thanks for the awesome input dearl! By teflon shaft collar are you talking about the shaft bearing thrust ring that goes onto the driveshaft? What jet unit and HP is that?

You are right, $60 for these bearings is quite expensive, especially if they arent sealed or anything special. So did you go with the napa bearings, or just re-install the used bearings? Thanks man!!

Oh, and did you have to remove the top snap ring to get the bearing housing out of the pump? I have a torch and heat gun.

Mine is a Mercury 90/65 2 stroke. The white Teflon shaft collar takes up the gap between the impeller and the shaft. Not sure if that's the right terminology for the part, My pump had a lot of chatter in it, once I broke it down I noticed the Teflon was in pieces. I got a new liner and key, problem solved. I re-used my old bearings, they didn't have any play in them. I did remove the top ring, didn't need a torch, it come right out with the right pliers.
 
dearl said:
Mine is a Mercury 90/65 2 stroke. The white Teflon shaft collar takes up the gap between the impeller and the shaft. Not sure if that's the right terminology for the part, My pump had a lot of chatter in it, once I broke it down I noticed the Teflon was in pieces. I got a new liner and key, problem solved. I re-used my old bearings, they didn't have any play in them. I did remove the top ring, didn't need a torch, it come right out with the right pliers.

Cool thanks. I was wondering why you had an extra bearing in there. The 60/40 has one, at least currently it does.

I wish my issue was from a bad plastic sleeve!! I guess what I was asking, was once you take that top ring loose does the bearing carrier drop from the lower unit? How did you get the bearings out? Slow and easy tapping I guess?
 
dearl said:
Some gentle persuasion was needed with a dead blow but from what I remember it wasn't all that bad.

Hahahaha, when "gentle" and "dead blow" are used in the same sentence :)

Thanks for the support, Ill let ya know how it goes. My bearing carrier doesn't seem to want to come loose from the pump housing. The top snap ring is rusted. I have a feeling my experience may be a little less gentle than yours! :lol:
 
Ok guys, got her all apart with nothing broken!!

You do NOT need to release the top snap ring to get the carrier out of the jet housing. Once you take the waterpump off and the 4 bolts that hold the carrier in, some tapping from the upper end of the driveshaft (and a night soaking in PB blaster) will pop the carrier and driveshaft out of the pump.

A little bit of heat on the carrier and I could knock that loose from the driveshaft. A socket extension and a hammer, and I slowly convinced the bearing off the driveshaft. Took about an hour to get it all apart.

Free-spinning the bearing, there is not a lot of noise, but definitely some. I am thinking this bearing is in decent shape, but still may be bad enough to cause the rattling sound that I am hearing when the impeller is installed. I am pretty sure that if it were coming from the block, it wouldn't make a difference whether the driveshaft was installed, or the impeller, but the noise would happen either way. At this point there is only one way to tell!

Now onto the bearing itself. You can see why they tell you that if you install the bearing backwards that you are SOL. This thing will barely spin if the load is on the wrong side. Being an angular bearing gives it more surface area while bearing a thrust load. The markings on the bearing are as follows: SKF 7305 BECBP USA 13 272C Explorer. If you look up SKY 7305 BECBP on ebay, the bearings are $55 or so. So I have confirmed that the reason OBJ is charging $60 is because that is what that bearing is worth. I can tell you one thing, you won't see me putting a $20 bearing on this jet foot!!!

So I will soon be ordering the bearing and seal kit from OBJ, now that I know which kit I need. Likely, I will take the driveshaft to the local machine shop and check to make sure it is true. I will also likely have them press the bearing onto the shaft because I don't want to score the shaft or ruin the bearing.
 
So I got everything ordered last week.

Cleaned up all my components and am ready for install. I am starting to get a little anxious about it because it seems not only do you need to press the bearing onto the driveshaft (a long piece of galvanized pipe to match the inner race can take care of that). You also need to press the out side of the bearing into the bell housing. It wouldnt be so bad but there is 2' of driveshaft on the same end that you need to press from. How in the world?!?!?!
 

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