Bigger Hammer?

[partingclouds]

Just pulled the transmission coupler enroute to a new PSS dripless unit. Super rusty nuts and Allen head bolts in the cast iron split coupler were no match for Weasel Piss. So amazing. However, now the real fun begins. Even after putting it to the torch and slathering Weasel Piss on it like holy water, beating it with a hammer did nothing. I've been using a wood block to support the shaft and one to take the hammer blows so l don't break the casting. No puller of any kind will be useful because the front of the coupler is solid cast iron. (Of course. Murphy's Law dictates that design of components should be as bizarre as possible wherever boat yoga in cramped spaces is required). So, should l just keep doing what hasn't worked thus far, but use a BFH instead of the 16 ounce beauty I've been smacking it with? I'd rather break it myself than hire someone to do that for me.

Thanks in advance, cruisers.

Partingclouds

[Tomodore]

Just be careful that the shocks/trauma you introduce to the shaft and coupling are not traveling to the transmission, I messed up the seal in my transmission whacking on my prop. I now have moved on to more creative errors after learning from the simple ones. If it comes to it a new shaft is not too expensive and if you cut it you can bring the section with the coupler to a machine shop. Time and frustration on one hand, money and progress on the other. Either way hope you’re sailing soon.

[AndyEss]

Go for a Bigger FH, but work up in stages. 16oz is pretty light for breaking free a probably 1 inch or so diameter prop shaft. Heat can’t hurt - unless you set your boat on fire or severely burn yourself

[boatpoker]

Bite the bullet ... 7" disc grinder with a cut-off wheel from Harbour Freight. Thats what I did after fighting it for a week.

[C420sailor]

Here is what worked for me.

I found a socket that fit perfectly on the end of the shaft, and produced a small (1/4” tops) gap between the coupler and the transmission output when mated.

I reinstalled the bolts, and gently and equally torqued everything up. The goal is to just put some tension on the bolts, putting the socket and shaft in compression. You aren’t pressing the shaft out.

Heat. Heat like your life depends on it, get that coupler nice and warm.

Take two hammers, mini sledges preferably, and shwack both sides of the coupler, 180° apart, simultaneously. The shock should break the shaft free, and it should pop out. I use this to remove stubborn props too. Use a puller to build some tension, then double hammer shwack. Off it comes. This technique works great for removing ball joint studs from steering knuckles, too.

If not, try a little more bolt tension, but do not overdo it—you do not want to damage your transmission.

This method works for me when all else fails.

[C420sailor]

Wait. The shaft doesn’t protrude through the coupler?!?!

Cut it.

[skipperpete]

Wedge open the split with your least favourite flat screwdrivers, give it all another soak and try again.
Oh! Take the allen head bolts out completely, they sometimes go through a relief in the shaft as an extra measure of security.

[south4320]

My shaft and coupler had a dowel through them which wasn't easy to see. Might be worth checking to make sure yours is not the same.