Me- Making Mistakes (M^3)

[Stephan]

Gents-
To remove my prop shaft I had to press it out of the coupler. I got some longer coupling bolts and put sockets of increasing lengths in between the shaft and the transmission, then tighten down the bolts - remove the bolts - insert a bigger socket and repeat.

This process was eventually successful but it was also efficient in producing these:

I cross threaded them and I was stuck not being able to back them off.
I did a lot wrong here-
I did use an impact gun (at first) which I now classify as a tool of mass destruction...
Didn't bathe the coupling in CX in the days leading up to its removal.
Didn't take my time and was anxious to get the job done.
Didn't remove stuff that was in my way and didn't light the area well.
Didn't effectively spread the coupler, just removed the set screw and bolts.

I would like to not do this again. I have been advised to use Never Seez in the future. I have been considering if I should have used bronze nuts on stainless steel bolts.
Please advise.
Thank you.
Stephan

[Bob H.]

Stephan, In the end you got to where you needed to be...the journey is part of the process..well done..you didn't give up..I done think bronze bolts are strong enough..and stainless may be too brittle..I will defer to Harry Babb on the right bolt to use..thats the beauty of the sandbox if one brother can't set you straight another will be right along to lend a hand. BH

[Harry Babb]

Stephan, working in tight places makes a guy get quite creative.

I have a friend that says "I can touch it.....I can see it....I just cannot do both at the same time".

I have seen some of those stuborn couplings that had to be cut off....looks like your one of the lucky ones.

As far as your method, if you don't have consequential damage to the flanges you did good.

The danger of pulling aganist the flange faces is the possibility of warping them. The one that I would be most concerned with is the drive flange on the gear.

To check it.....After sanding and cleaning the flange face....setup your indicator so that the stylus is on the Transmission Flange Face. Next, gently turn the flange thru a full rotation. If the flange is good you will see at the most about .001 TIR runout. In particular look for fluction between the bolt holes.....meaning highs and lows thru a single revolution.

The Coupling flange should be checked the same way.

Bolts.....stainless steel is never a good choice in this application. I would recommend a grade 8 bolt and even better...use a fine thread. With the fine thread you can develop more "PULL".

If you find yourself in this situation again I suggest that you get a 3/4" thick disc of steel the same diameter as the coupling flange and drill a bolt pattern to match the coupling......then use that disc to pull aganist and not the transmission flange.

hb

[Stephan]

Harry-
Thank you for the guidance. I really can't complain about access... the deck is up in preparation for replacing the bulkhead aft of the engines....
I'll check the output flange on the transmission... I hope this wasn't much bigger a mistake than I realized. I don't want to have a bill for the tuition to face the transmission output flange.
There is a next time coming very soon as the Starboard shaft was the prequel to the Port shaft... I have been treating that one with CX and plan a short pagan ceremony wher I will invoke UV's intercession and fully expect the coupling to drop off in my hand.... If not I remembered I have a puller like to give it a little push... and when none of that works I'll start drilling up some 3/4 inch like you instructed.

[mike ohlstein]

You probably didn't cross thread those nuts. Stainless steel galls pretty easily. Those things just welded themselves together. They were just a bad choice for the job.

[Rawleigh]

Also carefully applied heat will make a HUGE difference in getting them off. With a gas boat one has to be VERY careful about this, but it can be done with proper ventilation. A good place for an induction heater, right Harry!!

[Carl]

Like Harry said, Grade 8 Bolts.
SS does not come close to the strength of them and then as Mike said..plus they gall and lockup to you have to cut off.

I recommend people fit those Walters Clamp Fit Couplings to the shaft.
Makes assembly and disassemble a snap.



When done right...you tap (2) "Blade Screwdrivers" into the slots wedging them open a tad...then a soft mallet taps coupling on or off. Remove screwdrivers and your done.

Yes never sieze on coupling, and hardware.

Carl



Thanks for coupling picture insertion....

One thing to add...I never use the pin unless specifically told by customer...
Too tight, too loose, mushrooms and binds..can't get in, can't get out...falls out.
They always leave here perfect...but when introduced to "Mr Slammy" in a confined bilge space all bets are off....then comes corrosion and removal with Mr. Slammies Big Brother. To get'er back in...out comes the grinder...

I prefer split rings and counter bore setup as the prevention for having a shaft slide out of coupling when hard reversing with a Gung Ho captain.

[IRGuy]

Seeing that you bought a "Pittsburg" gear puller kit from (most likely) Harbor Freight I would get a set of the bolts recommended above and use them in place of what you have in the kit. IMHO Pittsburg stuff is great for the price, but some of their stuff is made from cheaper materials.

[bob lico]

That harmonic balancer tool is a great tool for engine harmonic balancer but NOT shaft coupling because your pulling with three bolts instead of five or six depending on size of shaft. As said grade 8 bolts never stainless with socket on shaft,soak with corrosion x day before and like Carl said use screw driver in split then one turn at a time on bolts in cross pattern.

[Harry Babb]

Just as Mike said......you did not cross thread or even strip those bolts.....they just siezed up.

I use a lot of the NyLoc nuts on things that I build. I have noticed that if you use a screw gun to tighten the nuts, the Nylon insert seems to build heat from friction and bam! ! she is galded and locked up. The same thing even happens to me when I use a ratchet and thread the nut on pretty fast....galls and its "lights out" for that bolt.

I do use the silver Anti Seize and it certainly seems to help. Going slower seems to be the trick with the NyLoc nuts.

I love to hate stainless steel for this very reason.

hb

[Harry Babb]

In particular look for fluction between the bolt holes.....

Wonder what in the hell "FLUCTION" is.......did anyone wonder?????


Lets try "FLUCTUATION"


hb

[Stephan]

Fluction is the causative factor leading to being flucked.....

[Bob H.]

By flucking to fast as harry noted leads to instant galling...ouch..harry is a wise man indeed...BH