How close shaft anode

[Sailfree]

I fitted the shaft anode about 15mm from P bracket thinking it would hold shaft in place if gearbox flange ever came undone. I hate holes in boats!!

Now realise it could be slightly resricting the flow of sea water along the cutless bearing grooves.

Does the cutless bearing need a flow of water through it or is hydrastatic pressure sufficient to ensure water remains in the grooves to lubricate the bearing?

Advice please before I go diving to reposition it!!

 

[Tranona]

Should not be a problem. The normal gap the other side is about 20mm.

 

[Skyva_2]

The probability of the shaft anode coming loose through erosion is quite high, some people recommend a jubilee clip to stop them rattling against the P bracket! That would also have the effect you want on the shaft.

Or a jubilee clip inboard of the stern gland - though not such a good idea with a Volvo seal?

 

[vyv_cox]

15 mm is fine on a 1 inch shaft. Mine has been like that for years.

I have never experienced a shaft anode coming loose. The method is simple. Tighten the screws as far as possible. Take two hammers, 2 lb is fine, one in each hand. Bang them together with the anode between such that the two halves are whacked together. Retighten the screws. Repeat until screws will tighten no more. The anode will remain in place throughout the season.

 

[TigaWave]

As a bearing supplier, 3.00mm is fine for water to enter/exit the bearing on beariungs up to 3".

With regards to shaft movement on rubber mounts we have seen 9.00mm fore and 9.00mm aft as a maximum for 1.5" shafts so 15.00mm will be fine.

 

[Quandary]

In addition, after you have secured your shaft anode, fill the depressions over the securing bolt heads and nuts with waterproof sealant, this prevents erosion on the seating of the securing bolts meaning that they will not work loose, the main part of the anode erodes away leaving the residue still secure on the shaft. If you don't do this the tension on the bolts can be lost allowing the anode to rotate at a different rate to the shaft until it wears through and falls off.