Pulled the drive today, clunking noise on 4.3 OMC Now

[MD-80]

This is my first post so if I have put this in the wrong section just let me know. I did a little searching but didn't' find anything that sounded similar. I have 1991 sea-swirl that is running a 43. OMC. I had it out last weekend and it was running great and when we went to take off one of the times I heard a louder noise that I had not heard before. I sound like a clunking noise coming from the out drive. I pulled the engine cover off and it didn't' sound like it was coming from the engine at all. At a idle speeds it sounds like something is rattling around in the outdirve at certain trim position it sounds different. The prop still spun though and we started to limp the boat back to the dock. After a while I decided to give it some more gas and the noise didn't' get worse so I gave it a little more and so on. We eventually reached a speed of about 35mph and the noise was completely gone. It almost seemed like the boat was running a lot quieter but when we slowed back down the noise came right back. This is my first boat but I feel I some mechanical skills and should be able to work on it with some guidance. What manuals do you recommend and what does it sound like the problem might be. Any help would be great.

 

[Boatin Bob]

Re: Another Noobie, Question about clunking noise on 4.3 OMC

Re: Another Noobie, Question about clunking noise on 4.3 OMC

Hard to say from your description but it could be the u-joints, did it make the noise even when in neutral at idle? (when was the last time the drive was off and the u-joints greased and gimbal bearing checked?) would also get it out of the water and first check the upper dipstick to see if it's full of lower unit oil, then I would pull the bottom screw and check for water in the oil and also the dreaded metal pieces sticking to the magnet. You can oder after market manuals from this site but I prefer the OMC original manual and sometimes you can find them on eBay.

 

[Purduebarry]

Re: Another Noobie, Question about clunking noise on 4.3 OMC

Re: Another Noobie, Question about clunking noise on 4.3 OMC

For the originals try here...they had mine but get out your wallet, worth it but pricey.

Call them and make sure you have the model number off of the engine!

http://www.kencook.com/evinrudejohnsonmanuals/index.cfm?fuseaction=home.main

 

[MD-80]

Re: Another Noobie, Question about clunking noise on 4.3 OMC

Re: Another Noobie, Question about clunking noise on 4.3 OMC

What else would you need for me to describe? As far as after market manuals which might be the best?

 

[MD-80]

Re: Another Noobie, Question about clunking noise on 4.3 OMC

Re: Another Noobie, Question about clunking noise on 4.3 OMC

Is the seloc one any good

 

[marunr]

Re: Another Noobie, Question about clunking noise on 4.3 OMC

Re: Another Noobie, Question about clunking noise on 4.3 OMC

Hi, and welcome to i-Boats and the world of OMC owners. I would advise you not to use your boat again until you read the site mentioned here. http://www.hastings.org/~stuart/cobra

Print it out and study it.

Drain your drive lube and check to see if there's any water in it. Look at the magnet on the drain plug and see if there are any metal shavings on it.

I have a seloc manual, and it's ok but there are some contradictions. Use the Hastings site to adjust your shift cables! I would buy the OMC manual, but I'm probably not going to keep my boat much longer.

It's very important to read the link I posted! You'll have to copy and paste the entire url since it's not showing properly on this post right now. You could be looking at several $1000's for repair otherwise.

Good luck!

 

[MD-80]

Re: Another Noobie, Question about clunking noise on 4.3 OMC

Re: Another Noobie, Question about clunking noise on 4.3 OMC

Based on my description do you believe it's already to late and I have damaged my gears. Now Im' a little worried. Until I get the manual does anyone know any decent sights that explain some basic boat maintenance, ie.. draining drive lube. I hate to sound like I don't' know anything but this is my first boat.

 

[marunr]

Re: Another Noobie, Question about clunking noise on 4.3 OMC

Re: Another Noobie, Question about clunking noise on 4.3 OMC

It's hard to say if it's too late. For starters, You need to drain the oil and look at the magnet on the drain plug.

First check the dipstick. It's the center screw in the middle of the top of the outdrive. (lower the unit first. You'll need to be out of the water of course)
if the oil is milky white, you have water in the drive and you'll have to pull the outdrive and check the bellows. You need the manual for this. You can drain the oil anyway, and it may not be possible to tell if water is in there by looking at the dipstick, so:

Put the dipstick back in, but don't screw it in. This will allow air in as you drain. Make sure all of the water has drained out on the ground, then put your pan under the unit. You will be draining about 2 quarts of oil. Unscrew the bottom drain plug. It's on the bottom, operator side of the unit. It should have a magnet on the tip of it which will hold metal shavings if your gears are destroyed. if the magnet is clean, you might be ok.

To do anything else, you need the manual and the hastings site print out. Do not re-fill the unit until you've read the manual. It must be re-filled from the middle plug...not the lower plug you drained from. OMC is different in this aspect. If someone tells you to refill from the bottom, that is wrong, so again, get the manual ASAP.

Pour some of the drained oil in to a clear glass. Water will settle in the bottom and you can see it. (This is why you need to let all of the water drain out, with the unit lowered, before you put the pan under it)

Good luck to you!

 

[MD-80]

Re: Another Noobie, Question about clunking noise on 4.3 OMC

Re: Another Noobie, Question about clunking noise on 4.3 OMC

Thanks alot for your help, anboy else feel free to chime in.

 

[MD-80]

Re: Another Noobie, Question about clunking noise on 4.3 OMC

Re: Another Noobie, Question about clunking noise on 4.3 OMC

anboy= anybody

 

[Don S]

Re: Another Noobie, Question about clunking noise on 4.3 OMC

Re: Another Noobie, Question about clunking noise on 4.3 OMC

Pull the drive off and check for water in the bellows.
If there is water, you need ujoints and bellows, and probably a gimbal bearing.
You will probably also have water in your drive and need to drain, replace the seal and possibly the input shaft yoke if the sealing surface is rusty,
Without dissassemby of the drive, there is no way of knowing the condition of the internal parts.

 

[MD-80]

Re: Another Noobie, Question about clunking noise on 4.3 OMC

Re: Another Noobie, Question about clunking noise on 4.3 OMC

Thanks everyone for your help. I ordered a manual a couple days ago and it should be here pretty soon. I do have a question though. Does anybody have any idea why I would have this loud knocking nose at the low speed and then at higher speeds it dissapears all together. To give a better description of the knocking noise would that at low speeds and idle it almost sounds like something is tumbling around in the outdrive and it's slightly random. It's rather loud but not any louder than the engine. It just sounds bad though. Just thought I would try to give a better description to see if anybody else has any ideas.

 

[MD-80]

Re: Another Noobie, Question about clunking noise on 4.3 OMC

Re: Another Noobie, Question about clunking noise on 4.3 OMC

Thought I wold give this one more bump before my manual gets here.

 

[MD-80]

Re: Another Noobie, Question about clunking noise on 4.3 OMC

Re: Another Noobie, Question about clunking noise on 4.3 OMC

I got my manual yesterday and I started work on the boat. I thought I would put up a few pictures and see what you guys think. The first thing I did was pull the dipstick and the oil seemed to be fine but I think it was low because once I cleaned it off and put it back in and checked it again there was no reading. I then drained the oil. The first picture is of the drain plug at the very bottom of the out drive. It appears that there is some amount of small pieces of metal on the plug and I wanted to see what you guys thought.

After the oil was removed I checked the plug in the middle which is the one I fill from correct? Or do I fill from the top. The manual says from the top I think but someone said above that I fill from the middle one. Anyway that plug had some grimy stuff on it and the very fine metal pieces about the same as the drain plug. This picture shows the plug I am referring to.

I then pulled the cover off of the top to look at those gears and here is what I saw. Do these look okay? I don't know if you can tell from the picture.

I think I screwed up and pulled this plug on the Port side (I think it's the port side) Water came out but I think there is a nut on the other side that is no longer in place that I need to screw it into. Anybody offer any guidance on this piece or at least what it called so I can look it up in the manual

The last pic shows what look like to be a tear in a sleeve I believe is called the u-joint bellows. Do every one agree with me that this needs to be replaced.

I noticed on the bottom side of the exhaust bellows there were holes along the whole side. This is normal right? They don’t' look like tears but Pre-cut holes.

I guess my next course of action is to pull the drive and check the u-joints. Does anyone have any other suggestions? By the way I did not see any water in the oil it appears to not be contaminated.

 

[MD-80]

Re: Question about clunking noise on 4.3 OMC Now with some Pics

Re: Question about clunking noise on 4.3 OMC Now with some Pics

I was going to ask next since I will probably go ahead and order the ujoint bellows and u-joints, where is the best place to get this from?

 

[Don S]

Re: Question about clunking noise on 4.3 OMC Now with some Pics

Re: Question about clunking noise on 4.3 OMC Now with some Pics

Yes, the bellows needs replaced, along with the ujoints and gimbal bearing. Also check the ujoint yoke where it goes into the drive. If it's rusty, it will eat up the seal just like sandpaper and let your gear lube out. Once that happens, you need a drive replacement. Can you say $$$$$
That screw you took out on the PORT (Yes, you are correct) side of your drive screws into a threaded plate, not just a nut. They fall down inside, but when you take the drive off to do the bellows, you can (usually with a lot of hassle) get it reattched.
Put a new oring on that top cover.
The magnet looks fine.
Remember one thing. If there was a gasket, seal, or oring on something when you took it apart, replace it. They are NOT reuseable, they just look that way sometimes.

 

[MD-80]

Re: Question about clunking noise on 4.3 OMC Now with some Pics

Re: Question about clunking noise on 4.3 OMC Now with some Pics

Thanks Don for your help. Do you know what that screw is for and is there supposed to be water behind it? I think there is supposed to a be a cobra sticker covering it. I have the manual so I will mainly work from that but is there anything that might not be in there that would be helpful to know when I go to take the drive off. Also last thing, based on that tear and the likelyhood that there is water in the bellows do you think that this could be a likely cause of the noise I heard?

 

[Don S]

Re: Question about clunking noise on 4.3 OMC Now with some Pics

Re: Question about clunking noise on 4.3 OMC Now with some Pics

I have no idea why that plate and screw were put in there.
As near as I can tell, OMC's engineers worked on the principal that if you can't dazzle them with brilliance, baffle them with BS.
There is a hole there, and they had to plug it. It's a water passage, so yes there will be water in it. Put it back together the way it's supposed to be and don't remove that screw again.
And yes, there was a Cobra sticker over it. Your basic out of sight out of mind type thing.
As far as you noise, when you add water in place of grease, yea, it makes noise and destroys bearings. Water is not a lubricant. And a lubricant is something bearings under stress need.

 

[MD-80]

Re: Question about clunking noise on 4.3 OMC Now with some Pics

Re: Question about clunking noise on 4.3 OMC Now with some Pics

I understand about the whole lubricant thing I was just trying to put my mind at ease about the gears in the lower units that's all.

 

[Boatin Bob]

Re: Question about clunking noise on 4.3 OMC Now with some Pics

Re: Question about clunking noise on 4.3 OMC Now with some Pics

MD-80 this link will show you an exploded view of that screw (the one you don't take off), look down in the lower left of the pic (item 14), there is one on each side. As Don ssaid there used to be a Cobra emblem there so most people didn't know there was a screw but a lot of them have fallen off now. This site is also good to order parts from. Cobra Upper