Prop shaft coupling

[jstic1]

Attached is a picture of the shaft coupling attached to I believe the Hurth transmission flange. I need to remove the prop shaft and wondering if I can use a puller to remove both the coupling and the transmission flange at the same time without causing any damage to the transmission since there is no gap to remove just the coupling. If not any thoughts on creating a gap?

[DougR]

So it looks like you have a Hurth (ZF) 630V or 63IV, and I suspect the shaft is tapered inside of the coupling.....

Make a steel disc about 1/2” thick to match the diameter of the flange, 5”, and drill four holes in it with the same hole pattern and diameter as the coupling holes. Make up four threaded studs long enough to extend thru the coupling and flange holes and also thru the steel plate which you are placing against the shaft end.

Use 8 nuts on the studs to clamp the gear box flange together with the prop shaft flange, and another 4 nuts on the side of the plate away from the transmission. You can thread on the shaft nut to protect the shaft threads just in case.... Now start to evenly tighten the nuts on the side of the plate away from the transmission and that will push the plate against the prop shaft. As you continue tightening the four nuts it will push the shaft out thru the coupling. Warming up the coupling wouldn’t hurt...

You might have to move the sea water strainer to get good access, and remember to remove the props as well.

DougR

[jstic1]

Thanks DourR. Correct it is a Hurth 630 V1 transmission. in lieu of fabricating something wouldn't your suggestion be the same as reinstalling the original 4 bolts and nuts that secure the shaft coupling to the transmission flange and use a gear puller where the prong ends are on the transmission flange and the forcing screw is at the end of the prop shaft? By turning the screw on the gear puller this should as well push out the prop shaft, correct?

[DougR]

A gear puller should also work if it’s heavy duty enough, if there is room to get it in there, and if you can get the jaws between the transmission flange and the gear case. Use care on the threaded end of the prop shaft......

If the jaws won’t fit between the transmission flange and the gear case, you might be able to push the prop ahead until it hits the strut which might open a gap between the transmission flange and the prop shaft flange.