Salt Water Crud - Frozen Gearshift Rod

Solittle

Fleet Admiral
Joined
Apr 28, 2002
Messages
7,518
I have a 1975 9.9 that I haven't run in a couple of years and decided to put it back in service. One of the first things I checked was the gearshift which turned out to be frozen.<br /><br />I dropped the lower unit and the cavity surrounding the gear shift rod is hard packed with what I think is salt water crud. The shift rod itself is frozen. The crud surronding it is nearly solid in texture and when scraped yields a small amount of white powder. I am having a problem getting this stuff out. I have been using a long screwdriver to scrape what I can get to but looking for other ideas.<br /><br />I was thinking of submerging it in water but wondering if there are other more effective solutions.<br /><br />Your ideas are - - - - -
 

walleyehed

Admiral
Joined
Jun 29, 2003
Messages
6,767
Re: Salt Water Crud - Frozen Gearshift Rod

Calcium, I believe....<br />The only thing I know that will remove it is phosphoric acid, and chipping away as it softens it. Of course you only want it in the general area of the calcium as to prevent other problems.<br />Kroil might help loosen up some of it too, as a penetrant(sp?).<br />Good luck!
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: Salt Water Crud - Frozen Gearshift Rod

solitle<br /> the only correct fix is to dissasemble the case and replace the shift bushing. if the rod sticks and causes a partial clutch engagement it will cause other problems. its quite common here
 

umblecumbuz

Lieutenant Junior Grade
Joined
Sep 25, 2004
Messages
1,062
Re: Salt Water Crud - Frozen Gearshift Rod

If you've got obvious hard deposits there, which have already no doubt started corrosion, do you think that's the only place you've got them?<br /><br />Belt and braces gives peace of mind! Examine everywhere, and clean with patience. There's no miracle-cure.<br /><br />Better a load of tedious cleaning now, replacing every item that's suspect, than problems later out on the water.<br /><br />Ciao
 

OBJ

Supreme Mariner
Joined
Dec 27, 2002
Messages
10,161
Re: Salt Water Crud - Frozen Gearshift Rod

If it's salt, take it out in the driveway and hit it with the garden hose. We have brine pumps at the plant that leak at the packing glands and grow huge clumps of coliflower. We just take a hose with a good stream and wash it off. Should work for the stuff in the cavity. Then as rodbolt posted, replace the shift bushing o-ring and bushing if needed.
 

walleyehed

Admiral
Joined
Jun 29, 2003
Messages
6,767
Re: Salt Water Crud - Frozen Gearshift Rod

I guess my point was clean it up and see what you have...then repair as needed. The aircraft tech comes out in me in these cases because it's usually best to clean what you can BEFORE dissasembly, so you can see what you are dealing with....2 different pages I guess.
 

umblecumbuz

Lieutenant Junior Grade
Joined
Sep 25, 2004
Messages
1,062
Re: Salt Water Crud - Frozen Gearshift Rod

You said that you hadn't touched this motor for a couple of years.<br /><br />Fresh brine deposits wash off, as OBJ says - as simple as cleaning down a boat after salt-water use. But two year old deposits will have hardened up, as you're already finding. They'll require more solid action. <br /><br />That's why I suggested a thorough inspection. Never leave what you can't see to chance.
 

steviecops

Chief Petty Officer
Joined
Oct 3, 2003
Messages
585
Re: Salt Water Crud - Frozen Gearshift Rod

I just had the same thing with a 9.9 that I have. Not quite as bad though, the shift rod was stiff rather than frozen, but that cavity had the same build up of the solid white stuff. I think it's calcium rather than salt.<br /><br />I just had to chip and scrape away the best I could, and ended up using a long drill bit and electric drill to get right down the bottom to clear the hole that drains the lower unit. I think once that hole gets blocked, the water trapped in there causes the build up.<br /><br />I was lucky, the worst of the build up was below the shift rod in that tiny V shaped cavity, so I could see that I wasn't damaging anything with the drill, and when I got it all out the shift rod worked nice and easy.<br /><br />You just have to get in there and shovel it out!<br /><br />Good luck.<br />Steve
 

Paul Moir

Admiral
Joined
Nov 5, 2002
Messages
6,847
Re: Salt Water Crud - Frozen Gearshift Rod

I might be totally out to lunch on this, but for what it's worth... <br />It seems to me that there's two types of white crud we run into. One is the (relatively) fluffy white stuff that covers the insides of water jackets. It seems to me that this is calcium carbonate, and descaling chemicals and flushers remove it. I remember reading somewhere that it's one of the few substances that tends to precipitate out of water when it's heated, instead of when it's cold. Which explains why it ends up covering the insides of the engine but not, say, the water pump pickup passage.<br />Then there's the nasty white stuff that surrounds especially stainless fasteners where they run into aluminium. That's aluminium oxide and it's as hard as hades. The worst experience I ever had with that was on a lower unit extension that had 6" long stainless thru-bolts. Where it passed through the extension, the aluminum had corroded and the 'white stuff' had it's death grip on it. As far as I know, no reasonable chemicals attack aluminum oxide and it must be removed mechanically. It only seems to appear around dissimilair metals, so presumably it's the result of galvanic action.<br />I expect it's this second 'white stuff' that has grown around your shift rod seeing that it's stainless.
 

OBJ

Supreme Mariner
Joined
Dec 27, 2002
Messages
10,161
Re: Salt Water Crud - Frozen Gearshift Rod

Paul, not being around salt water as some of you folks are(hence my post above), is there a "different" type of corrosion that happens in salt water as opposed to fresh? I think that's what your post is alluding to but just want to be sure.
 

Paul Moir

Admiral
Joined
Nov 5, 2002
Messages
6,847
Re: Salt Water Crud - Frozen Gearshift Rod

Jim, I don't think so. But then again, what do i know: I can't think of a single outboard that I've worked on that I knew for sure had only been used in fresh water. My impression of fresh water corrosion and deposits is that it's pretty much the same as salt - it just takes longer.<br /><br />What I was getting at is that there's two different but often confused forms of 'white stuff' that plague us. Calcium scale from (for?) shellfish and aluminum oxide from galvanic corrosion. Sometimes people call it/them 'Salt', but I'm sure it's not actually that. Neither even tastes very salty.
 

Dunaruna

Admiral
Joined
May 2, 2003
Messages
6,027
Re: Salt Water Crud - Frozen Gearshift Rod

Galvanic corrosion is very common in salt water and its causes are varied and sometimes very complicated (as I have learned recently :eek: ). In some cases it can be CAUSED by the sacraficial anodes, even different types of stainless steel can react with each other - as I said, it can be complicated. If your problem is galavanic corrosion it is indicating a potentially serious problem.<br /><br />Galvanic corrosion and electrolysis occurs in fresh and salt water but it occurs quicker in salt water because the water is ladden with conductive salts and other impurities.<br /><br />Aldo
 

OBJ

Supreme Mariner
Joined
Dec 27, 2002
Messages
10,161
Re: Salt Water Crud - Frozen Gearshift Rod

Thanks Paul and Aldo for your input. It just hits like a bat along side the head when you think about it.....well me anyhow. I work in a power plant that cools it's generator with water. Water so pure it won't conduct electricity. (it's the impurities that conduct, not the H2O and salt is an impurity) Salt won't plate out due to electrical current. But metals will. Thus corrosion. Corrosion speeds up more in salt water than in fresh and as Aldo said, can be quicker or slower depending on the metal composition. <br /><br />OK....that's Galvanic Corrosion 101 for this days lesson.<br /><br />Thanks again guys.
 

umblecumbuz

Lieutenant Junior Grade
Joined
Sep 25, 2004
Messages
1,062
Re: Salt Water Crud - Frozen Gearshift Rod

This is a no-win setup.<br /><br />Corrosion occurs:<br /><br />1. Because of electrolytic action.<br />Once a boat’s in water, the water is the electrolite. When it’s sitting on a trailer, unless the hull’s dry (ie. bilge water remaining or floatation foam damp, or rain), electrolysis can still continue. So corrosion still continues.<br /><br />2. Because metals oxidise while in contact with air. <br />Hence the use of stainless steel, which slows down corrosion. Snag is, using stainless nuts and bolts produces its own problems. A bolt and nut both made from 316 grade stainless will tend to fuse together due to the pressure between them displacing the natural surface coating (known as cold welding). A bolt running through aluminium will cause havoc to both metals, although this process is slowed with good sacrificial linkups (anodes wired in).<br /><br />There are ways to minimise these problems, but the bottom line is - if your boat comes in contact with air or water, you’ve got corrosion!<br /><br />Have a nice day!
 

Solittle

Fleet Admiral
Joined
Apr 28, 2002
Messages
7,518
Re: Salt Water Crud - Frozen Gearshift Rod

Great info guys one and all - An update - -<br /><br />After a bit of fussin, chippin & diggin. I got enough of the crud out to clear the shift rod. I<br /><br />Some background on the motor - It was given to me by a friend about 15 years ago. He used it as an auxiliary for his 26' sailboat. At some point he replaced it with an electric start and stuck this one in a corner of his garage where it sat for a number of years. When I got it I replaced the water pump and ran it once in a while on a 12' skiff. It ran well. When not in use it has sat in my garage. <br /><br />When I took it out the other day I noticed a spot of what looked like minor corrosion on the lower leg above the gearcase. I scraped thinking it would come right off. Well it did but the metal underneath was soft. Before I knew it I was all the way through the casing (picture below). This is on the port side and directly above what might be a drain hole which is still plugged with crud. <br /><br />questions - <br /><br />1. Is the small hole a drain hole?<br />2. I am thinking of plugging the larger hole with Marine Tex since this is just a cavity to be drained. I could have it welded but don't know if that would do any better than Marine Tex. I may also put a larger diameter drain hole through whatever I plug the hole with.<br /><br />
DSCF0003acopy.jpg
<br /><br />Once I get past this and get it running I think I may pull the head & check for corrosion in the water passages.<br /><br />Ahhh these projects - - just think if it were not for them and spending time here on iboats I might have to watch TV - - Ugggghhh!!!
 

OBJ

Supreme Mariner
Joined
Dec 27, 2002
Messages
10,161
Re: Salt Water Crud - Frozen Gearshift Rod

OUCH!! That's a hole. Before you decide on how to patch it, might want to check the metal further around it for thickness and more corrosion. Might be better off getting it welded but might have to take the darn thing apart so as not to mess the parts up. I would drill the drain hole larger also. I do it a lot at the shop on a lot of the older motors. Nothing worse than getting into that cavity and finding it full of mud...so I drill the hole a little larger, file it down a little and touch it up. Most times the owner don't even notice it. A larger hole helps drain of large pieces of junk that would plug up a smaller hole.
 

umblecumbuz

Lieutenant Junior Grade
Joined
Sep 25, 2004
Messages
1,062
Re: Salt Water Crud - Frozen Gearshift Rod

And yes - that lower hole is a drain hole, and is often the culprit, because it blocks inside and then - as you've found - the rest of the inside cavity slowly gets filled and eats itself away.
 

Dunaruna

Admiral
Joined
May 2, 2003
Messages
6,027
Re: Salt Water Crud - Frozen Gearshift Rod

Solittle, how do you get the arrows and words in the pic? What program do you use? It looks very professional.<br /><br />Every time I try it, it ends up looking like its been done by a 3 year old.<br /><br />Aldo
 

Solittle

Fleet Admiral
Joined
Apr 28, 2002
Messages
7,518
Re: Salt Water Crud - Frozen Gearshift Rod

Aldo - For the arrows and text I used Adobe's Photo Shop Elements that came with my Cannon Scanner. I don't know if you can get a freebe version. Elements is the low cost of their expensive big brother. I don't use it much but it seems to have the basics and lotsa stuff I'll probably never use..
 
Top