Lower unit leaking...can't get prop off!

[Texasmark]

Re: Lower unit leaking...can't get prop off!

The thrust washer is in front of the prop and keeps it from climbing up into your LU. You can rig a chain around the prop and use a 3 pronged flywheel puller to put some tension on it. No heat and no banging on it as you have seals, gears, and bearings you don't want to mess up. Just keep at it, lots of penetrating oil. When you get it off and finish your business, put some grease on the prop shaft splines and you won't have this problem again. Removing the prop once per year in high corrosive environments will help too.

Mark

 

[waflyboy]

Re: Lower unit leaking...can't get prop off!

Good deal. I'll plan to replace the prop after replacing the seal. Will definitely remove it at least once a year from now on. I have no idea when the prop was removed last. (I bought the boat last summer.)

Thanks again for all the help!

 

[waflyboy]

Re: Lower unit leaking...can't get prop off!

Ok, so I've tried just about everything I can think of to remove the sleeve from the prop shaft. Lost of PB Blaster, pulling, tapping, applying heat. I can't get it to even wiggle a little. I think it's stuck on there really good. You can see at bit of corrosion on the shaft where it meets the sleeve. (See post #17, last pic.)

Any suggestions on what to do next? I'm seriously considering just finding a replacement lower unit.... would probably cost me less than taking it to a shop, no?

 

[wired247]

Re: Lower unit leaking...can't get prop off!

You can find a good inline lower for a few hundred bucks.

If it were mine I'd cut through the rubber with a die grinder and cut the rubber off. Then I'd do a deep score on the inner sleeve that meet the spines. I'd lower the shaft onto a few wood blocks to act as a backup then I'd place a large chisel on the score and smack it with a BFH to split the sleeve.

 

[Chris1956]

Re: Lower unit leaking...can't get prop off!

The hub is brass so it is relatively soft. Cut the rubber off any way you can, and then follow Wired's advice. I would try a dremel with a metal cutting disc. Crack the hub open with a cold chistle. It should come off. Worst case is if you have to crack both sides....

 

[waflyboy]

Re: Lower unit leaking...can't get prop off!

Cool deal, thanks guys. Working on borrowing a Dremmel now. Will give it a try and report back with results.

 

[Texasmark]

Re: Lower unit leaking...can't get prop off!

The hub is brass so it is relatively soft. Cut the rubber off any way you can, and then follow Wired's advice. I would try a dremel with a metal cutting disc. Crack the hub open with a cold chistle. It should come off. Worst case is if you have to crack both sides....

If you resort to the chisel, I'd put something behind the shaft so that your banging is supported rather than the prop shaft getting all the force. May not matter since you are dealing with some tough critter....SS parts, but it wouldn't hurt. I'd try the conventional puller now if you can get it on the thrust washer like "belairbrian" suggested. When you get your new prop you ought to go ahead and get a new thrust washer and locking nut. If you buy one of the new props with the removable hub, you may need a new thrust washer anyway.

On buying the new prop, keep in mind that if you want the same performance you had it's apples and apples. Props of different mfgrs/types will have different performance for the same diameter and pitch.

And like Fleetwin said, don't forget to grease the shaft and pull the prop every once in awhile. In salt water, once a year is probably a good idea.

Mark

 

[waflyboy]

Re: Lower unit leaking...can't get prop off!

Great, many thanks to all for the wonderful information. Here's what happened next:

I finally had some time today to work on removing the prop. I cut back the rubber with a knife so the sleeve was exposed, then used a Dremel with a metal cutting blade to make two cuts, opposite each other, along its length. I was able to pry between the cuts and get some PB Blaster in there. Eventually after a lot of prying, chiseling, and heat I was able to get the whole sleeve off. (Although in several pieces.) Under it was a lot of corrosion, most of which came off with some scrubbing. I did cut into a couple of splines on the shaft, but I suspect it's still serviceable.

As for the oil leak, my time budget on this project is blown (got other projects around the house, and my wife says they're more important!) so I took the ship to a respectable marine shop in the area. Hopefully I've got the hard part done and finding/fixing the leak will be easy for them.

Thanks again for the help and advice. Will post some pics when (if?) I get a new prop installed and get her in the water this summer.

 

[waflyboy]

Re: Lower unit leaking...can't get prop off!

An update for anybody that's interested:

The marine shop that worked on the boat said the prop shaft front oil seal was leaking pretty bad. They replaced it, then pressure tested again and found that the other seal was also leaking - but very slowly. In the process of taking things apart to replace the other seal, they encountered a considerable amount of corrosion and were unable to take it apart "without risking damage to the lower unit."

They also said there was considerable pitting (from corrosion) on the prop shaft behind the the seal. So, it sounds like the lower unit is nearing the end.

I had them check the powerhead compression - 120, 120, 120, 115. Seems like the powerhead is good, so maybe I'll be on the lookout for a replacement lower unit.

I put on a brand new prop and took the boat out this weekend. It ran great - for about 10 minutes. Then I suddenly lost RPMs to just above idle, and couldn't get it any higher the rest of the day. When the throttle was advanced, it sounded like the engine was "loading up", but the RPM wouldn't increase. The fuel was brand new, carbs and fuel pumps rebuilt last year (less than 10 running hours ago), new fuel lines. Preliminary research seems to point toward a bad stator perhaps? This weekend I'm going to OHMs test the stator; hopefully that will yield some insight. (Thread on this topic posted here: http://forums.iboats.com/mercury-ma...rbolt-suddenly-wont-go-above-idle-622517.html)

Thanks again for all of your contributions. This is my first boat - I've owned it for just over a year and have learned a great deal. Perhaps the moral of the story is to save you money and buy new when you can afford it?