View Full Version : Need help to get coupling apart???

05-07-2011, 11:30 AM
Trying to get my coupling apart in order to replace the rubber hose around my packing box. Was told by the supplier for the packing rope that I needed to disconnect coupling remoove cotter key, then loosen up nut on driveshaft, reconnect coupler to output flange on transmission. Then tighten the bolts on the coupling which in turn would push the driveshaft back resulting in the coupling being released from the taper on the driveshaft.
Have done this and put quite a bit of torque on the couling bolts to the point that I would have thought that the coupling would have unseated from the shaft.
Wanted to check with you guys and see if I am doing it right and just need to not wimp out and keep tightening the coupling bolts. OR that there is something else I need to do to get the coupling seperated.
Thanks for the help.

Boat is a 1988 PS 190 with 1:1 trans and a 351

Pictured with cotterrr key in place, however cotter key has been removed, driveshaft nut has been backed out and coupling reconnected and tightened against nut trying to back driveshaft out of coupling

Packing box with hose trying to replace on packing box

05-07-2011, 01:14 PM
I've used a similar method with longer bolts and a deep socket to push the shaft out. It did require some muscle but it eventually popped out. You may want to try some penetrating oil as well.

05-08-2011, 08:10 AM
Place a large dead blow hammer on one side of the coupler barrell,with the bolts tight smack the other side of the barrell,that always works for me.

05-08-2011, 09:41 AM
Pour some heat on that rusty ole coupler! Propane torch and a spray bottle with water in it should get it moving for you. Heat it up, spray it down to cool It off. Smack it with the hammer as suggested above
Keep repeating until its free again, free again!

05-08-2011, 10:21 AM
Maybe I'm not reading your post correctly, but you have to take the shaft nut all the way off, not just loosen it. As others have stated, soak it pretty good with some WD-40 first and let it work for several hours. Once the nut is all the way off, place a socket between the two couplings so that the prop shaft will be pressed out when you insert the bolts and start tightening. I've never had to hit mine with a hammer, but I've broken a few gear pullers trying to get the coupling off. The socket between the two couplings seems to work the best, just tightening each bolt a little at a time. And yes, it may take a LOT of tightening! If all else fails, smack it with the hammer!:)

05-08-2011, 11:07 AM
I would use something like PB blaster or even some tranny fluid rather than WD40, it evaporates to quickly to be there for "hours"

when you reassemble the coupling and shaft, I would use some anti-seize sparingly so it doesn't sling all over the bilge