Sunday, 5 April 2009

Sailboat Engine Gearbox Reconditioning

The gearbox on a friends yacht started playing up recently. It is a simple box with a three position gear lever - forward, astern and neutral - which is all you need for the average sailboat.

From time to time it would slip out of gear when going forward and then a few seconds later it would grab again and go back into gear. This was ok for a time, but it was noted that as is always the case, these malfunctions gradually deteriorate and become worse, never better, and that at some point in the future it would need some attention. Sure enough it gradually got worse and was staying longer out of gear before going back in again, to the point where the decision was made to take some positive action.

Apart from this being potentially dangerous i.e. not being able to go astern when docking etc., or subsequent damage arising from being unable to avoid a collision when under power, it is good seamanship practice to keep right on top of these maintenance jobs when they occur - not much later when they could potentially put you, your boat, your crew and others at risk.

This particular gearbox is a simple Hurth (Hurth 150) one speed box attached to a marinised Perkins 4108 (48hp) diesel engine of hazy history. The boat was built in 1988 and the engine could well have had hours on it prior to it being marinised. The Hurth would have been fitted new at that time and twenty five hundred hours have been run on the combination in the ensuing years.

The image to the right shows you the installation in the engine room with the gear lever to the right hand side of the box, and also shows you the shaft coupling. Following a considerable amount of research we have located a marine engineer who can service and recondition the gearbox providing we can get it to him. This is the point we are currently at now, and facing up to diving into the bilge to uncouple the the shaft from the gearbox and remove the gearbox from the engine. The date has been set and all going well we should have it out of the boat and to the engineer by the afternoon of Tuesday 14th April.

This blog is to put you on notice of our intention and let you know that I will be posting another blog shortly giving you a detailed description of our progress - hopefully good but warts and all including skinned knuckles etc - so watch this space.

You can read more about engine repairs and maintenance whilst cruising, in my ebook 'Voyage of the Little Ship 'Tere Moana' downloadable from my website

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