flex coupling / shaft removal advice needed..

[eagleswing]

can anyone with a centa or vetus flex coupling to your marine engine answer the following questions:

it appears that these flex couplings mount easily with 6 bolts onto the coupling in the gearbox (my engine = a yanmar 3JH4E 40 hp, for which there is an adapter flange)

1--in order to remove the prop shaft from the centa or vetus, do you just undo the 6 mounting bolts of the flex-coupler , which bolt heads s face aft in a circular arrangement ? and then start pulling the propeller shaft outboard and aft?

2--what bolts retain the prop shaft inside the flexible coupling ? those same 6 bolts, or some other set of bolts or fasteners that need to be loosened?i cannot understand how the force created by the fore and aft install directions of the 6 bolts convert to a clamping force , to keep the prop shaft engaged inside the flex coupling itself.

i need to replace a bent prop shaft and worn out cutless bearing . am having trouble getting the prop shaft out. i am not able to pull the prop shaft out rearward from the flex coupling even though i've already removed the 6 flex coupling bolts. (i have already removed the propeller and cutless bearing from the prop shaft....)

thanks in advance for as much detailed advice as you can supply...

on the hard, and going nowhere til i figure this one out...

 

[doug748]

On the Centaflex the shaft is held by a collet which is drawn onto a taper by the bolts. It will not release unless it is pushed off this taper.
You will see that there are two or three other holes on the face of the coupling (they may have plastic plugs in them). After making sure the six clamping bolts are loose, screw bolts into these holes, tighten them, and the collet will release. Thats it.
The screwthreads are metric, 10mm I think, maybe 12.

 

[davidwf]

The manuals for all vetus flex coupling are here http://www.vetusweb.com/manuals_43.php

 

[eagleswing]

thanks for secret plug info..

" On the Centaflex the shaft is held by a collet which is drawn onto a taper by the bolts. It will not release unless it is pushed off this taper...You will see that there are two or three other holes on the face of the coupling (they may have plastic plugs in them). After making sure the six clamping bolts are loose, screw bolts into these holes, tighten them, and the collet will release. Thats it."--

BRILLIANT ! so i'll just re use the same m12 bolts i just took out of the 6 aft -facing holes , thread them in to he 3 holes covered by the plastic plugs.. then the prop shaft can be pulled out ?

now why could centa and vetus not have stated this in their manuals, both of which i have ??


thanks...


The screwthreads are metric, 10mm I think, maybe 12.

 

[doug748]

BRILLIANT ! so i'll just re use the same m12 bolts i just took out of the 6 aft -facing holes , thread them in to he 3 holes covered by the plastic plugs.. then the prop shaft can be pulled out ?

now why could centa and vetus not have stated this in their manuals, both of which i have ??
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That is more or less it, though I think you will find the 3 threaded holes are 10mm.