Transmission removal

[Clyde_Wanderer]

I have a bad oil leak from the Hurth HBW 50 transmission on my Hummingbird 30, I am going to have to remove it for repair.
Can this task be carried out while the boat is in the water, ie, will the water pour in when I detach the shaft from the box? as I guess I will need to move it back quite a way from box flange to facilitate removal of the box.
Would appreciate any advice.
While I am on, has anyone got any information, ie, history etc on the Hummingbirds?

 

[seasprite]

Hi CW

I would recommend speaking with Derek from Yachting Sports at Hamble Point, He's a real star when it comes to help.

Good luck !

SS.

 

[oldharry]

It depends on the type of stern gland you have. A conventional gland will tolerate the shaft being moved right back to the coupling, although it might dribble a little - just pump in more grease!

I have done this several times. On some boats the shaft will only move a little way before hitting the rudder.

If you have to remove the coupling, clamp a pair of molegrips to the shaft to stop it disappearing down the stern tube - or you would be in trouble!

 

[Gordonmc]

It shouldn't be a problem to move the shaft back far enough for the coupling bolts to be removed. I did the job with a Borg Warner box in a 30 footer last year. The shaft is fairly new, but even if it a bit worn where the packing is in contact moving it back will bring "new" metal down, so the stuffing should be tighter, if anything.
Just be careful in hauling out the box you don't stand on the shaft. It doesn't take much pressure to put it out of true.

 

[Clyde_Wanderer]

Is the shaft parallel the whole way to the front face of the prop? are there no raised sections where it passes through the stern tube, etc,?

Thanks for the advice all.