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transmission to prop shaft disconnect question
Posted: Sun Aug 26, 2012 11:17 pm
by rspecops
Ok I have taken the 4 bolts that seem to connect prop shaft coupler to transmission flange or coupler off. The prop shaft is not coming loose from transmission. I also completely loosened stuffing box. Prop was removed for transport and I can not rotate prop shaft by hand. I am wanting the prop shaft disconnected so I can briefly put transmission in gear when I do my every couple weeks crankup on the engine while boat is blocked up out of water for renovation projects. One other thing I have checked and there is no set screw on prop shaft coupler. May be a key I have not found but no set screw. This is on a B/W velvet drive with Crusader 350. Transmission is straight or direct drive 1:1.
Posted: Sun Aug 26, 2012 11:33 pm
by rspecops
Posted: Mon Aug 27, 2012 5:27 am
by Allen Sr
Try tightening the packing nut down just enough to give space between the coupler and the packing nut so there is room enough for the shaft to slide back. There is no key on the coupler itself, only on the prop shaft/coupler half and the output shaft of the tranny/coupler.
Posted: Mon Aug 27, 2012 5:44 am
by vabeach1234
It appears the shaft log hose is too long. I would think you'd want some shaft exposed just after the coupler. That way the shaft can slid aft and also you can ajust the packing nut and change the packing down the road.
Posted: Mon Aug 27, 2012 6:20 am
by prowlersfish
vabeach1234 wrote:It appears the shaft log hose is too long. I would think you'd want some shaft exposed just after the coupler. That way the shaft can slid aft and also you can ajust the packing nut and change the packing down the road.
Looking at the photo I agree
Posted: Mon Aug 27, 2012 6:38 am
by rspecops
The shaft log hose being too long, yep that is got to be it. I thought this configuration looked a little strange compared to some I saw pictures of. I have plenty of shaft log hose to work with. I will start by cutting a couple inches back. Just so I am clear, obviously there is no set screw on the prop shaft coupler to secure the coupler to shaft. But there will be something like a woodruff key on prop shaft to secure shaft to coupler???
Posted: Mon Aug 27, 2012 8:24 am
by BobCT
Mine has a set screw and woodruff key. Yes, it must at least be keyed which I'm sure you will see when you remove it.
You should also rotate the clamps so the screws are 180 degrees apart as opposed to right next to each other.
Bob
Posted: Mon Aug 27, 2012 12:32 pm
by gettaway
Bob, are you refering to the key on the shaft to the coupler?
On my boat the Velvet drives and the Twin Disc's have a centering ring the couplings, one side is female the other is male, and it is a pretty close fit, so this may be what is temporarly holding these couplings together. the lip is about 1/8 or 1/16th of an inch.
also agree that the shaft log hose is much long
Posted: Mon Aug 27, 2012 12:53 pm
by gettaway
here are few photos of the shaft coupler and you can see the centering ring

Posted: Mon Aug 27, 2012 2:03 pm
by larryeddington
My bet the centering ring, mine was pretty tight when took it apart, but you do need some room to slide shaft back.
Posted: Wed Aug 29, 2012 7:15 pm
by larryeddington
larryeddington wrote:My bet the centering ring, mine was pretty tight when took it apart, but you do need some room to slide shaft back.
Most of the pressed on couplers have set screws as well my pics of couplers and removal.
http://www.trojanboats.net/wforum/viewt ... ht=coupler
Posted: Thu Aug 30, 2012 8:34 am
by jav
Am I the only one thinking the obvious? While it does seem your shaft/shaft log clearances could be improved... this seems like quite a project in order to excersize your gears on the hard.
It seems much simpler to put some good lubricant on the shaft/cutlass bearing and a little on the shaft/packing union for the short bits of dry running you will do. I think it's a great idea to run the equipment once in a while on the hard but the shaft spinning would be less worrisome to me than impellers and exhaust hose damage.... and even these would be fine with short bits of dry running.
Posted: Thu Aug 30, 2012 11:30 am
by larryeddington
Noticed the locking jam nut is not against the packing nut, baybe was maybe not, if not it should be to keep everything water tight.
I would be interested to see how whoever put that together got it all in there with so little slack.

Posted: Thu Aug 30, 2012 11:43 pm
by rspecops
Thanks again for the responses and advise. Been around boats all my life but this is the very first inboard engine I have owned. I am learning as I go and have learned a great deal from you guys. I am going to replace cutlass bearing and restuff packing box as part of my renovations. I unscrewed the jam nut from packing nut to just see if that would loosen things a bit. I also thought how in the world was this ever put in with the seemingly non existence slack in the system.