Fubar times 2

[BlueBeast]

1976 Johnson Seahorse model number 55EL76E, serial number E4473745

I am trying to drop my lower unit to replace the water pump.

I have disconnected the shift linkage and removed one of the lower unit bolts(hidden bolt).
All 4 of the lower units bolts and the trim tab bolt I tried to remove but all the heads have broken off.
The lower unit should now slide off over the bolts. But these are stainless steel bolts in aluminum case.
I think the only thing holding it on now is friction.
The lower unit will not budge when hit with a rubber hammer. And I have to be careful when I hit it because the aluminum bends.

Anybody got any ideas?

 

[retiredfornow]

Re: Fubar times 2

See if there's a bolt up in the hole where the tab was. Sounds like you still have a bolt in there somewhere.

 

[Joe Reeves]

Re: Fubar times 2

The bolts are not pure stainless.... if they were, they would be brittle to a point whereas they would snap due to vibration. They are a mixture and are prone to salt corrosion seizing and locking them solid into position as you have unfortunately discovered.

It is best to have a hand held propane torch in one hand and a wrench in the other when removing bolts in an outboard. The heat allows the surrounding aluminum to expand around the bolt shaft, helping the bolt to be freed.

By the same token, even if you have actually removed all of the retaining bolts, the shafts/ studs of the bolts are frozen solid within the lower unit bolt holes.... and you'll need to be using heat in those areas no doubt. Good luck.

 

[lindy46]

Re: Fubar times 2

If all of the bolts are out (or broken) and the shift rod is disconnected, it's probable that the driveshaft is stuck or possibly rusted to the crank. Try to get some penetrating oil up there and let it soak.

 

[Joe Reeves]

Re: Fubar times 2

If the lower unit does not drop down any at all = bolts seized.

If the lower unit drops down approximately 1/2" = driveshaft seized.

 

[omcnut]

Re: Fubar times 2

had the same problem with an old 15 78model had to stand it upside down and put acid down the broken lower unit bolt holes to eat at the corrosion as a week of heat and penetrating oil didnt budge it!

 

[BlueBeast]

Re: Fubar times 2

Acid? What kind?

 

[BlueBeast]

Re: Fubar times 2

I have a 2 ton mini jack that will sit on one of the fins and then push against the brace that wraps around the unit. Does anybody have any objections to this idea?
http://www.amazon.com/Torin-T90203-Hydraulic-Bottle-Jack/dp/B0002H3364

 

[GA_Boater]

Re: Fubar times 2

I have a 2 ton mini jack that will sit on one of the fins and then push against the brace that wraps around the unit. Does anybody have any objections to this idea?
http://www.amazon.com/Torin-T90203-Hydraulic-Bottle-Jack/dp/B0002H3364

None whatsoever, it's your motor so do what you want. If the AL is bending using a rubber mallet, what is going to bend using a jack? You said it isn't moving at all. Have you tried PB blaster or penetrating oil at each of the bolts? And maybe some warming of those areas - Not a lot of heat, just healthy warming. There may be corrosion between the bolt shafts and the housing. It this a saltwater motor?

 

[AlTn]

Re: Fubar times 2

similar experience to yours with a 71 25 hp. salty dog.... I used a piece of 2x4 the length of the av plate and pounded on it with a 2 lb. ball peen hammer...front to back/side to side...it finally created a small space of separation then came on off with continued pounding..never did get easy..the av plate got a little "wavy" but it straightened put w/o much effort once removed

 

[omcnut]

Re: Fubar times 2

Acid? What kind?

sulfuric like you buy at the hardwear for cleaning brickwork took a couple of hours but it worked just be shure to wear gloves and goggles nasty stuff!

 

[Joe Reeves]

Re: Fubar times 2

How far has the lower unit dropped down from the engine? If none at all, have a friend or friends join you in having a few hand held propane torches heat the aluminum surrounding the broken studs.

 

[BlueBeast]

Re: Fubar times 2

Thanks for all the advice. The lower unit bolt heads are broken off and all the lower unit bolts are seized. There is no gap between the lower unit and the mid section. So far I have hit the av plate with a rubber hammer and no separation, just bends in the av plate. I have been spraying Penetrating Oil in all the bolt holes and around the seem. I am going to try the 2x4 on the av plate and hit it with a hammer, my 2 ton jack, and the acid and see what happens. I'll let you all know what the results are.

 

[jbjennings]

Re: Fubar times 2

Joe Reeves told you to use heat. That's what I'd use. If I were to listen to anyone about removing a lower unit that was corroded stuck on the bolts, I'd listen to a fellow from Florida (lots of fresh and salt water there) that's done it once or twice. The corrosion isn't likely that big of a deal between the seams because they're the same kind of metal touching. The corrosion is just where Joe said it was---between the bolt studs and housing surrounding them. That's where you need the heat. Don't heat it so hot that you liquify the aluminum alloy housing (aluminum melts about 900 degrees without ANY warning--it doesn't glow first or whatever), just enough to get it off. If you keep beating on that plate, it WILL break, BTW. A hammer is not your friend on an outboard.
JMO,
JBJ

 

[omcnut]

Re: Fubar times 2

Joe Reeves told you to use heat. That's what I'd use. If I were to listen to anyone about removing a lower unit that was corroded stuck on the bolts, I'd listen to a fellow from Florida (lots of fresh and salt water there) that's done it once or twice. The corrosion isn't likely that big of a deal between the seams because they're the same kind of metal touching. The corrosion is just where Joe said it was---between the bolt studs and housing surrounding them. That's where you need the heat. Don't heat it so hot that you liquify the aluminum alloy housing (aluminum melts about 900 degrees without ANY warning--it doesn't glow first or whatever), just enough to get it off. If you keep beating on that plate, it WILL break, BTW. A hammer is not your friend on an outboard.
JMO,
JBJ

yeah i can see what youre saying here in australia all my boating is done in saltwater and ive done this before acid is a last resort but much preferable to a jack or f.b.h. heat is great if it works i used acid after a week of heat and penetrating oil had no effect..take from it what you will....

 

[5150abf]

Re: Fubar times 2

You list 5 bolts removed but there are 6, you don't mention the one under the tab and you want to TAP, as in hit it slightly harder than you would hit your own finger, this is cast aluminum you are whacking and it doesn't like to be whacked and will break quite easilly, if you are bending it you are hitting it to hard.

Corrosion doesn't respond to hard hits, you want the vibration from a ton of small hit to break it loose, Joe has been an OMC mechanic for many many years, if he told me to put peanut butter on my engine I would do it, listen to Joe.

 

[jbjennings]

Re: Fubar times 2

yeah i can see what youre saying here in australia all my boating is done in saltwater and ive done this before acid is a last resort but much preferable to a jack or f.b.h. heat is great if it works i used acid after a week of heat and penetrating oil had no effect..take from it what you will....

I will add your acid suggestion into my book of tricks! Hearing that you tried it after the heat and it was effective is interesting, especially since you run in saltwater. Always eager to learn new ways of solving these types of problems, and appreciate your advice. The heat has always worked for me, but I don't work on saltwater motors and therefore you have far more experience than I. I've not ever had a lot of luck with penetrating oil on outboards, myself.......
thanks again,
JBJ

 

[BlueBeast]

Re: Fubar times 2

I got a PB Blaster and a 4lb hammer with a piece of 2x4. With some time I was able to get a gap between units and then finally it dropped. I had to cut the trim tab bolt once it was visible in the gap, it just did not want to budge. Thanks Everyone