Thrust bearing

[vic008 17]

First time with a rubber mounted engine (20 hp). Does it need a thrust bearing on the prop shaft?

[Chewing Gum 17]

Not normally. Probably need a flexible coupling though and careful alignment.

If you install an aquadrive type coupling that has a cv type joint you then need a thrust bearing.

[idlerboat 116]

No.

The gearbox should be quite capable of taking the thrust.

 

Unless there is a major change of direction from the gearbox output flange to the shaft angle.......in this case you may use a thrust bearing with a python drive (or any other angle connection...even a car uni joint)

 

If you put a flexible coupling between your gearbox output flange and prop shaft flange....just remember you will be moving the prop back by aprox 30 to 40 mm..

 

......ps...dont stress......when you ask the same questions with 700hp per side.....

[Atom Ant 0]

I would have thought the answer was that it depends on the design of the engine mounts. Given that the prop thrust has to push against something, it will push against the engine mounts if there is no thrust bearing to take the load. Yes agreed that the gearbox may have load bearing capabilities (depending on its design) but surely the thrust load has to be transferred to the boat at some stage?

[eighty8 1]

some engine mounts like Aquadrive (also known as Metalastic or Cusyfloat) can take thrust, however its likely that your gearbox can also take care of this. A thrust bearing will help reduce vibration & noise by dampening it out through the hull via a cross member, but unless you have these problems first it shouldn't be essential in a modern marine engine/gearbox in a sail boat

[rossd 16]

I always have a big debate with myself weather 2 get factory or aftermarket. Yanmar 12 hp dealer engine mounts $120 + so I went with some aftermarket industrial $40 + for same dimentions. Then for the gush drive where the rubber was starting to part company with the steel I was to scared to get a factory price so got aftermarket plastic jobby but stung $400 + cannot win.