P bracket bearing

[David of Essex]

Hi
How much movement in the prop shaft is advisable in the P bracket bearing. Any ideas to how many hours you should get and what is the bearing made of.
Thanks
David

 

[omega2]

Generally about 1/16th to 1/8th up and down. Do you feel vibrations at present? Not sure about hours too many variables, bearing is usually a brass tube with a rubber insert lubricated by water. This may assist. www.clementsmarine.co.uk

 

[David of Essex]

Boat out of the water for anti fowling . Single shaft Merry Fisher 925' only done just over 100 hours. Just checking and learning. Thanks for the info.
David

 

[TigaWave]

Movement depends on bearing material, but 1% of shaft diameter and its getting worn with a composite bearing.

Bearing material can be a nitrile rubber (in a bronze sleeve or a phenolic sleeve) or a composite. They can be a press fit or a clearance fit bedded on epoxy.

Hours depend on the ammount of sand and silt in the water and also the ammount of marine growth. Microscopic growth on the shaft or bearing can be highly abrasive, this material can wear the shaft as well as the bearing surface. This is worth checking as changing the bearing is not always the answer.