Outdrive Noise. How Much?

[Condor1970]

Well, after this boat has been sitting for over a year, I finally got the engine running today. After pumping the throttle, and lots of little backfiring, it finally cleaned itself out, and runs good at an idle. The carb was just full of gunk.

Now, I as a new boat owner, I noticed the outdrive does make a bit of running noise when idling. Sounds like bearing noise, but not howling like a bad bearing would normally indicate to me at least. However, you can definitely hear a noticeable running sound. Like a bearing with no grease. I did give it a good several shots of grease until it was gushing out the back. I assume the Zerk fitting on the very top is for the Gimbal bearing, correct? Or is that just the top bearing for the gimbal itself?

Do I have to pull the lower to grease the gimbal bearing?

The sound actually sounds like it was coming from aft of the gimbel, so maybe it could be the U-joints? Those haven't been greased for probably 4 years now.

What do you guys think about this?

 

[UNSUREBOATGUY]

If yours is an older Alpha like mine, the zerk for the gimble bearing should be on the starboard side of the transom assembly below half way down (assuming yours is the greaseable variety). You can pump in a little grease without removing the outdrive.

 

[Bt Doctur]

As a new owner you should get yourself the manual and start doing some reading. Outdrives DO NOT make noise. You need to pull the drive and inspect the bellows for water, rusted parts, or gear oil. You don't list the engine, engine serial number or type of outdrive. In most cases the top fitting is for the steering arm, the 2 side ones are for the hinge pins, and the bottom one for the lower swivel pin, the one on the side for the gimbal bearing.
Did you check the oil condition and oil level in the drive ?

 

[ktbarrentine]

What was the trim angle of your outdrive. Hopefully trimmed to near level. Hopefully NOT trimmed to the "trailer" position. U-joints will make a heck of a racket if the drive is not trimmed properly when running on muffs (of in the water, for that matter!) and that leads to early u-joint failure. (hmmm...you are operating on muffs, right???!!??)

 

[Condor1970]

I do know most things that need to be done. I'm an engineer, with a full mouth of teeth. And no, I do not play the banjo. haha. (wish I did though)

However, the boat is an older boat, and did not come with any manuals. I'll see if I can get some from the owner later next week when he's available.

The outdrive is lowered level with the boat. I know better than to run the engine/outdrive trailered up.

I have already changed all fluids. Outdrive gear oil, flushed the trim system with all new trim fluid, oil change, new fuel/water sep, and a new starter. Pulled the plugs and inspected, and cleaned the fuel pump filter. The engine does run, but it needs to be run-in, because it sat for so long. It is finally idling, but whenever I try to engage the outdrive to test it, the engine immediately dies because it can't handle the torque yet. What does bother me though, is there is a noticeable noise form the very upper portion of the outdrive when idling and not engaged, like a bad bearing or something.

I did give the gimbal several shots of fresh grease on the side Zerk (yes, I found it), and there was no change in the noise. Even if it was shy of grease, the bearing should quiet a little when you fire in some fresh grease, even when the bearing is going bad. So, I'm starting to wonder if it is something else.

The outdrive is coming off next weekend to grease everything, check bellows, and check engine alignment. When I get a gasket kit, everything will get checked and greased then. The U-joints could also be bare, since they have not been greased in so long.

Bt Doctur... You know, if everyone just read manuals, and didn't bother with any inquisitive comments... there would be no reason for an online forum, and you would have no one to harass. ;o)

So, when idling, and disengaged, the outdrive should make "zero" noise?

 

[ktbarrentine]

You can get the manual you need online here by visiting the "adults only" sticky at the beginning of this forum. Great place to start. Lots of good information for inquisitive minds (this is coming from another engineer).
You can also pop the top cover on the outdrive and take a peak inside to see the condition of the gears. No, probably cant tell if you have a bad bearing by that look-see, but you may get a gander of other noise-causing problems in that area of the drive.
Surprised that your engine dies when you try to put it in gear. I would suspect maybe a lower shift cable problem that is causing the shift interrupt switch to engage when it shouldn't. The prop out of water is not any sort of load on the engine/outdrive, since all the parts of the outdrive are still turning (except of course the prop shaft and prop) when the drive is "disengaged".

 

[alldodge]

:welcome: to the forum

Condor, My questions come as I don't know how much you know about the drives so some are simplistic. When ever the engine is running the drive shaft is turning and the top half of the drive has gears spinning.

Did you fill the drive using a pump which pumps the lube in from the bottom until it comes out the top vent hole?

 

[Bt Doctur]

~~ but whenever I try to engage the outdrive to test it, the engine immediately dies because it can't handle the torque yet. What does bother me though, is there is a noticeable noise form the very upper portion of the outdrive when idling and not engaged, like a bad bearing or something.

But you did not remove the drive to inspect anything. shift interrupter killing the engine from a bad lower cable

~~I did give the gimbal several shots of fresh grease on the side Zerk (yes, I found it), and there was no change in the noise. Even if it was shy of grease, the bearing should quiet a little when you fire in some fresh grease, even when the bearing is going bad. So, I'm starting to wonder if it is something else

Nope, gimbal bearings don't act like that when there rusted out.

~~Bt Doctur... You know, if everyone just read manuals, and didn't bother with any inquisitive comments... there would be no reason for an online forum, and you would have no one to harass. ;o)

The manuals I refer to are the manuals for the engine and outdrive service, not operator manuals. As far as I`m concerned there should be a Federal Test Procedure BEFORE people are allowed to purchase marine vessels

 

[Condor1970]

Ok, I went into town, and met the guy who has all the original manuals. He gave me the 1986-89 Mercruiser Stern Drives manual, which looks to have just about everything. Old manual, but seems very complete.

Tried to run the engine again later today, and it just sputters and dies. It really needs a good carb cleaning. Ran ok this morning, but opbviously has more gunk in there now that it's been sitting a while with some gas in it to dissolve a lot of the gunk.

I really just need to get the engine running properly first. Then, I can pull the lower, and do a much better inspection.

Yes, I filled the lower form the bottom with Quicksilver HP gear lube, and a bottle pump.

I guess I should let everyone know. I'm quite capable of doing maintenance, etc. I'm just not an expert on troubleshooting problems with outdrives, because I've never owned one before.

BT Doctur, I really appreciate the input. Shift interrupter, and lower cable. I'll read up on it tonight.

 

[achris]

Stop what you are doing right now.... You need to pull the drive and make sure that running the engine isn't going to destroy the drive! It's all well and good having the engine running nicely if in the process you have bad bearings in the drive that collapse and take the whole drive out with them. So, step ONE, pull the drive, service the water pump, check and grease the universal joints, check the engine alignment, check and grease the gimbal bearing. Once you have the drive halves back together, pressure and vacuum test before filling with the right oil, the right way, to the right level. THEN put the drive back on and work on the engine....

 

[Condor1970]

^^^^ If that's the case, then I guess I can shutdown any further work on the engine until I get the gasket kit in the mail. In the mean time, I can finish the wood repairs I am doing. This may actually be a blessing in disguise.

Also, when it comes to engine work. The gas tank was completely full when I bought it. The guy kept it full to keep condensation out, which is fine. However, it's been in the tank for over a year now, and the gas itself is slowly turning yellowish in color. I think it is varnishing, and maybe not good to run through the engine. What should I do about this? Should I just use it up?

 

[achris]

If the fuel smells sour it off, dump it.

 

[Condor1970]

Pulled the lower off this morning. This is what I found.

First I checked engine alignment and the gimbal bearing. Both are perfect. Alignment bar slides in straight and snug with no movement or play in the bearing. Gimbal bearing rolls smooth and easy, no gritty feel at all. Greased bearing again to make sure it was full, and clean out excess from area.

Bellows appears to be fine. No visible holes. No remnants of water or salt inside the bellows.

The U-joints are solid with no play in the roller pins. However, they were almost completely dry. It took a good 4 shots of grease to fill each joint with fresh grease, and very little old grease emerged from the seals when full. Fresh grease with a touch of black leftover is all that emerged.

The shifter appears to work fine forward and reverse.

Also, as far as the bearing noise goes. I am of the opinion that it is probably the upper drive shaft bearing. I will get myself a socket to remove the upper housing cover, and inspect it. If needed, I believe I can replace that without having to tear apart the whole lower to do so.

A lower impellar kit is in the mail.


Now, the shifter cable.....

There is a small amount of salt build up on the bottom of the trough area beneath the cable. I inspected the cable bellows, and it appears fine. The fitting is also tight. The side of the main gasket for the lower however was not greased, and very dry. In fact the whole main gasket was not greased when installed, and very dry. That area of the gasket is very narrow, and if splashing water was to get in there, I would say that is the spot. The owner has not had the lower open for over 4 years, and who knows if the last guy who had it open cleaned out that little area. For all I know it could be 25 years of build up.

The metal shift linkage on the end of the shift cable appears to be in good shape. The screw on the end that is wired on and holds the cable in place is still there, but I do notice it is rusty, and there is a little bit of play between the cable itself and the shift linkage. It slides forward and aft about 1/8".

Is this a problem?

 

[Bt Doctur]

~~The metal shift linkage on the end of the shift cable appears to be in good shape. The screw on the end that is wired on and holds the cable in place is still there, but I do notice it is rusty, and there is a little bit of play between the cable itself and the shift linkage. It slides forward and aft about 1/8".
The slide should not have any front to back slop. the set screw is adjusted until the slide can just spin freely. Remove the safety wire and try to tighten it a bit. might have to use some heat to free it. With too much play you will never get the travel correct.
The salt deposits are sometimes called "mud", they can get packed into the slide during reverse and with enough mud, it will prevent you from getting full reverse

 

[Condor1970]

Okie Doke. I'll soak it in some Pen oil, and free it up to adjust the linkage set screw. Then, rewire it. Thanks.

 

[Condor1970]

Well, I've got good news and bad news on this.

The bad news is, try as I might, from Pen oil to WD-40, to a blow torch to heat the shift linkage, that little set screw on the end is not coming out. It has a thorough Zen relationship with that linkage.

The sort of good news is, I got ahold of the original owner, and he said 4 years ago when the mechanic pulled it apart, he also noted it moved a little, and was probably like that since inception. As a result he left it, and it never seemed to affect the way the boat felt or ran.

So, I have decided to do the same. I rewired it, heavily greased everything, and put it back together with a new gasket set. If I notice any issues, it will come apart and get replaced next year when I do maintenance again.

Next step is to install a new impellar, and try to replace the upper drive shaft bearing. I'm certain the upper drive shaft bearing is my noise culprit after checking the gimbal, and testing engine alignment.

P.S. My boat is parked on level ground, but aft of the boat my yard slopes down. Never try to drop and service the lower, while working on a slope. What a pain.

 

[ktbarrentine]

Kinda interesting that you opt to do your impeller replacement after you put the drive back on the boat. Most folks would take the whole thing to the bench and separate the halves there and do the impeller work, followed by a pressure test of the whole thing, since you had the drive off to work on the shift slide. I find it so much easier to put the drive back together while on the the bench (or rather, in my homemade drive stand). Dont have to worry about the elevational issues you referred to, either while removing just the lower half from the boat. You're gonna have to have the upper off the boat to replace the upper drive bearings anyways. Or maybe I am just reading your post wrong and overthinking it.

 

[NHGuy]

The bearing that inputs the power to the top of the drive is actually a good sized bearing cluster. If it's spins like butter put everything together before changing it and see if the drive is quiet with the u joints lubricated.
Changing that bearing requires a special tool to get the gears shimmed to mesh correctly. And another unusual one to set the preload. To see how it's done visit the stickies at the top of the forum. Chris has a video on it.

 

[airshot]

Just a suggestion here, if you pull the outdrive off again, before reinstalling it use your hand and coat everything with a coat of grease. I found in the past the outdrive could be difficult to remove due to some minor corrosion or crud on the mating surfaces. So when reinstalling the outdrive I coat everything and I mean everything with a coat of grease by hand. I include a light coat on gasket surfaces as well. Since then I have never had an issue removing an outdrive and do not find the corrosion/crud buildup on mating surfaces. I read many complaints about difficulty removing unit, but if you grease everything it slides off with ease.

 

[Condor1970]

Yes, I have a regular habit of greasing gaskets. I rebuild/overhaul industrial equipment (pumps, etc) all the time. Outdrives are something new to me.


Also did a lot of reading online. Apparently, a lot of mechanics feel you replace the upper shaft bearing without doing a whole preload procedure. The practice which apparently is done frequently, is simply reusing the original shims in the housing to ensure the same load on the shaft when you torque the cover back on. This allows you to replace that bearing without having to remove the outdrive.

Does this make sense?