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Late 70s Merc 50HP - Prop Seized to Shaft

travis0332

travis0332

Member
Hello, I have a 70s Merc 500 that I'm trying to replaced dinged up stainless prop for a shiny new one. Previous owner apparently didn't grease spline because its absolutely frozen on. I've sprayed penetrating oils into hub, heated with a propane torch and attached a harmonic puller that I rigged up with a chain. It ended up snapping the chain when I tightened it with ratchet. I've hit it with a hammer but am afraid of damaging prop shaft.

Anything else to try before I attempt to cut it off? I have an angle grinder but not sure if that's best to use for this. Any tips or advice is much appreciated.
 
Try the same prop puller technique again, wrapping a cable or chain around the prop with a puller and let time be your friend. Tighten the puller very tight and let it it sit for a day. Tighten the puller a 1/4 turn each day. The prop will come off or the rubber hub will separate from the propeller. I've done this with props and flywheels. I had an engine that took 10 days for the flywheel to pop with the constant pressure each day. Nothing broken, no beating, or heating.
 
Thank you for suggestion Fitz! Just tightened up puller with strong rope and a ratchet strap over the top for more strength. Will cross my fingers. Only downside is I may be fishing from shore on day off next week Lol. But hell, I'd MUCH RATHER have this thing pulled off then to perform exploratory surgery on it with an angle grinder. Will post back and see what happens, thanks again.
 
You'll probably end up ripping the prop off the rubber center hub, which is fine. One can then heat the hub with a torch and get the thing off at last. The inner hub is replaceable.

Jeff
 
fastjeff said:
You'll probably end up ripping the prop off the rubber center hub, which is fine. One can then heat the hub with a torch and get the thing off at last. The inner hub is replaceable.

Jeff
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Hi Jeff I would be okay with that. The prop was dinged up but now its quite mangled after getting at it with a hammer earlier. Just want removed now lol. Was curious if you think I should be planning to replace oil seal on prop shaft, assuming ill need to eventually torch this hub off most likely?
 
If you torch the prop you will cook the propshaft seal, then you will need to purchase the spanner wrench to remove the locknut (left hand thread) remove the nut and pull the reverse gear and bearing carrier to replace the seal.
 
If you didn't get it off yet, try the rust blaster that I use. Mix some fresh acetone @ 50/50 with automatic trans fluid. Soak er down.
 
timguy said:
If you didn't get it off yet, try the rust blaster that I use. Mix some fresh acetone @ 50/50 with automatic trans fluid. Soak er down.
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Thanks Tim, will keep that in mind. On day 4 will puller attached and it definitely has moved about 2 cm so I'm pretty excited about that! Should be another day or two and should be in the clear.
 
Looks like the center spline is still there and the hub did not separate from the propeller, so the spline was just welded to the propshaft?
 
fitz73222 said:
Looks like the center spline is still there and the hub did not separate from the propeller, so the spline was just welded to the propshaft?
Click to expand...

Yep no separation from the hub. I really don't understand why it was so stuck? Really no noticeable corrosion, the prop shaft cleaned right up. It needed the puller all the way to the end to completely remove, even once it "broke free."
 
Not sure if this is relevant but I have a story, one time, long ago I made the terrible mistake of putting Never Sieze on a propshaft used in salt water on 35 Merc I bought new in '84, I changed the waterpump religiously every 2 years and greased the propshaft. We'll that was a big mistake. Prop was welded to the shaft in two years. That's where I learned "the persuasion" technique. Never Sieze supposedly is aluminum based and I guess one metal met another in saltwater and they made a sieze baby. When I pulled it apart, same thing no real evidence of why they were stuck. Now only 2-4C is what's between the shaft and the spline.
 
Very interesting. I use anti seize here in fresh water.....works pretty darn well. Salt water may effect things differently.
 
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