Graham Harvey

Thanks for the advice Tony. I will check the cable operation as you describe next time I'm on the boat.

I have now taken off the unit containing the gearchange lever & confirmed that it is working smoothly with three 'detent' positions. There are no signs of the moving part of the mechanism binding or rubbing on any surface due to insufficient clearance related to the gasket thickness. It seems that the stiffness is due to some resistance of the gearbox internal (sliding) parts? I fear that I am lumbered with a stiff, imprecise gear shift or else remove, strip & have the gearbox overhauled.

I have spoken to TW Marine who are, as you say, most knowledgeable & helpful. I have received some advice which I shall act on shortly. The gearshift movement is very stiff both forwards & backwards with a further problem of not being able to find neutral easily. Having detached the Morse cable from the arm on top of the gearbox, it is possible to shift gear by hand but against considerable resistance. The advice I have received is as follows: If the fitting containing the gearshift arm was taken off for some reason it might have been replaced without the appropriately thick gasket. When re-fitted this might cause the mechanism to be located too tightly, that is, to cause it to bind on the adjacent surface? This seems to be distinctly possible to me. I shall investigate.

The gearbox on this Bukh dv 36 is a ZF BW 7 model. I think that it the type most commonly fitted to this engine & the DV 48. It has oil up to the diostick level.

The gearshift lever on my ZF gearbox is very stiff. Particularly trying to find neutral is difficult without going through it into either forward or reverse. The problem is not the morse cable as I tested the box with it detached. I wonder if there is any form of adjustment possible with the mechanism?

box