"Grinding" noise from sterndrive

[Captain Obvious]

I have a 1988 19' bowrider with a 4.3 liter Mercruiser and Alpha One sterndrive.

I've noticed the power steering fluid leaks slowly (maybe 1-2 oz per week), and I can't find the leak.

There is an unsettling grinding noise that has started about the same time as the leak. It happens when I turn the wheel at idle, and even when I trim the motor.

I checked the transmission fluid in the resevoir for the sterndrive, and it's fine. Engine oil is also at a good level.

Any help is appreciated! I pretty much operate on a 2nd grade level on mechanical issues

 

[Don S]

Re: "Grinding" noise from sterndrive

Moving to I/O forum

 

[Don S]

Re: "Grinding" noise from sterndrive

You need to pull the outdrive and check for water in the bellows. Water in the bearings will cause the noise when turning and trimming.

The PS leak could be going overboard thru the power steering coolser, but that would be a very small leak and doubtfull. I would be looking for leaks around the PS cylinder on the transom and the base of the PS pump.

 

[ziggy]

Re: "Grinding" noise from sterndrive

ya might try to isolate the noise with a hearing hose or the likes.......seems to me not knowing diddly about a boat power steering that if it's looseing fluid that'd be a good place to listen with the hose for a start.......any ol hose. it amplifies the sound when ya move it from here to there.....

You need to pull the outdrive and check for water in the bellows.

ya already did this right co....end of year preventitive maint........ lubed the coupler, ujoints, inspected the gimble brg by feel, and looked for water......

I checked the transmission fluid in the resevoir for the sterndrive

we understand what ya mean co...but i/o's don't have transmissions....ya need a service manual...the oem one would be good....

get one here......which one i don't know though..... 6 & 7 look likely to me though....bet someone straightens me out if i'm leading ya astray......

"http://www-alt.mercurymarine.com/mnetdata/sisdata/srvcovr.pdf"

 

[Captain Obvious]

Re: "Grinding" noise from sterndrive

Sorry for posting in the wrong spot Don.

I haven't done any year end maintenance as I live in Florida and planned on doing fluid changes etc in January. I bought the boat this year, and the drive has been off and all you suggested was done this spring. I've only run about 60 gallons of gas through it since (no hour meter).

Listening to it today, it sounds like it is coming from the drive shaft between the motor and the stern drive. It has been progressivly getting worse, so I'm going to lube everything first to see if that helps.

Thanks for the manuals and the help!

 

[Don S]

Re: "Grinding" noise from sterndrive

Like I said earlier.

You need to pull the outdrive and check for water in the bellows. Water in the bearings will cause the noise when turning and trimming.

Doesn't matter how many gallons or hours or whatever. If there is water in the bellows, it makes a poor lubricant, and rust sure does make make bearings noisy.

 

[achris]

Re: "Grinding" noise from sterndrive

One of the inherent problems with the Mercruisers of that era is that the bellhousing hinge pins are about 2 threads too long. Over time, obviously it depends on how much the boat is used, the end of the hinge pin rubs on the side of the bellows, creating a nice place for water to enter. I have replaced the bellows on all of my friends boats (and my own) for this reason. After I saw the first one I checked all the others and found they all had the same problem. After you remove the leg, and if you find water in there (and I think you will) turn the steering fully one way and check carefully on the side of the bellows for a hole worn on the top of one of the folds. If you don't see it one one side, check the other.

Chris..........

 

[Captain Obvious]

Re: "Grinding" noise from sterndrive

Allll right.

I've come out of denial and realize that I really need to pull the drive off. I have a lot of fear associated with starting something that I could make worse, or get into a situation where I need to buy 200 specialty tools to complete the job.

I've been searching the forum (and yes reading the manual ) for the past few days and have a couple questions:

1. It seems like after putting the drive in forward, removing the necessary power steering connections, and loosening the bolts, that there is little mention of anything else before sliding the drive off.

Is there anything else I need to know before taking it off? (like oil going everywhere, or a certain way to store the drive)


2. Also, I plan on purchasing the specified lube, oils, and replacement gasket before starting, but is there anything else I should plan on?


3. The power steering leak is definately contained in the boat. There is fluid in the bildge area, I just can't tell where it's coming from. I thought I'd put some white paper down all under the motor to see if drips show up in a certain area. Sound good?


Again, I'm REAL new at boating, and really appreciate the help (and your patience)!

 

[Haut Medoc]

Re: "Grinding" noise from sterndrive

Allll right.

I've come out of denial and realize that I really need to pull the drive off. I have a lot of fear associated with starting something that I could make worse, or get into a situation where I need to buy 200 specialty tools to complete the job.

I've been searching the forum (and yes reading the manual ) for the past few days and have a couple questions:

1. It seems like after putting the drive in forward, removing the necessary power steering connections, and loosening the bolts, that there is little mention of anything else before sliding the drive off.

Is there anything else I need to know before taking it off? (like oil going everywhere, or a certain way to store the drive)
No........


2. Also, I plan on purchasing the specified lube, oils, and replacement gasket before starting, but is there anything else I should plan on?
The likleyhood of water in your bellows.....


3. The power steering leak is definately contained in the boat. There is fluid in the bildge area, I just can't tell where it's coming from. I thought I'd put some white paper down all under the motor to see if drips show up in a certain area. Sound good?
No, get in there with a flashlight & look....
There are only so many places it will leak, as Don S outlined......
You may need to remove some seating to get a good look at the power steering cooler.......

Again, I'm REAL new at boating, and really appreciate the help (and your patience)!

Good Luck!.....

 

[HT32BSX115]

Re: "Grinding" noise from sterndrive

Howdy,

Well removing the drive is probably "second grade Level" so you're probably ok there.

No, oil will not "go everywhere"........
You do NEED TO READ THE SERVICE MANUAL in the R&R section so you don't break something.

The power steering leak is a separate issue.

After pulling it you may have to just take it to a rebuilder depending on what the U-joints look like etc.

Good luck.


Rick

 

[achris]

Re: "Grinding" noise from sterndrive

CO,

Have you checked the bellows for any obvious holes yet?

Remove a leg:

1. Put in forward gear.
2. Remove trim ram aft anchor pin.
3. Remove 6 bellhousing nuts.
4. Slide leg aft.
5. Drop on floor because you didn't realize how heavy it was

Total time, start to finish - 6 minutes!

Cheers,

Chris..............

 

[Bondo]

Re: "Grinding" noise from sterndrive

5. Drop on floor because you didn't realize how heavy it was

Ayuh,......... About 80/85lbs. actually...............

 

[Don S]

Re: "Grinding" noise from sterndrive

5. Drop on floor because you didn't realize how heavy it was

Even if the weight of it doesn't bother ya, when that ujoint assembly pinches you, you will drop the drive Trust me :redface:

 

[flabum]

Re: "Grinding" noise from sterndrive

you will be needing a Gimball Bearing

 

[Don S]

Re: "Grinding" noise from sterndrive

you will be needing a Gimball Bearing

And you came to that conclusion using what method of troubleshooting. Or are you hoping to be correct by using the WAG method?

 

[flabum]

Re: "Grinding" noise from sterndrive

And you came to that conclusion using what method of troubleshooting. Or are you hoping to be correct by using the WAG method?

He stated the grinding noise gets worse while turning and trimming. Classice indication of a rusty gimball bearing.

 

[JustJason]

Re: "Grinding" noise from sterndrive

1. Put in forward gear.
2. XXXXXXXXXXXXXX
3. Remove 6 bellhousing nuts.
4. use trim ram to bump the drive back a couple of inches
4 1/2. but not all the way off.... just enough to "break the seal" so to speak
4 3/4. dissconect the trim rams
5. Drop on floor because you didn't realize how heavy it was
5 1/2 Definitely watch out for the XXXX'in pinch

 

[Captain Obvious]

Re: "Grinding" noise from sterndrive

Can't wait to drop this thing and make a mess! Maybe I get a chance tonight to start the show.

Maybe I'll grab the bottom and let my teenager hold the top near the drive shaft. Kids heal quicker than adults right?

 

[Captain Obvious]

Re: "Grinding" noise from sterndrive

Got a small problem getting the drive all the way off. I put it in forward, but it doesn't come all the way off. It moved back about an inch, enough that I can fit my finger in the gap.


Got a bigger problem as water came out as soon as I broke the seal. What next?

 

[flabum]

Re: "Grinding" noise from sterndrive

Put a short piece of 2X4 between the top cover and ujoint housing and lift the drive....