Originally Posted by stillbuilding
Well, it is said that there are no stupid questions so here goes.
I have a Perkins
135HP pushing a 2.43:1 reduction gear
to a 26" prop.
I would like thrust block and cv joint/flexible shaft connection. Looks like Python Drive, Aquadrive or Orion units. Which are fine but seems outrageously expensive for what is a very simple and old technology.
Is there any reason why I could not use a heavy duty auto CV joint/shaft which are sold for peanuts in comparison? I imagine there are autos which have torque and wear solutions far greater than needed for my little diesel
I chose the Aqua Drive unit. It is more than a "U" joint. First off it has a thrust bearing that delivers the propulsion
thrust, as well as the stresses from snagging a crab pot, to the engine bed
, RATHER than the engine, it's rubber feet, or it's bearings.
Then it has TWO "U" joints, connected together by a short TELESCOPING shaft, all inside a rubber bellows. This allows the engine to be way out of alignment, and move all around, even for and aft shaking, without moving the prop shaft at all! The shaft just spins... This feature makes a dripless shaft seal
, like my PSS, work infinitely better.
Together, these features make the engine's feet, bearings, and the shaft seal
last much longer. It also makes it where engine to shaft alignment need not be constantly monitored or adjusted. Original alignment is much easier two.
We installed our engine within 5 degrees, 16 years and thousands of engine hours ago, and have never touched the alignment since. Although I may change the soft Yanmar
rubber feet soon anyway, they have no sign of wear.
At the time, we paid $700 something for the small Aquadrive CV joint. While I could have cobbled together "something" cheaper, I could not even come close to creating something as utilitarian and long lived as this unit, for that price
If you want one, buy it... IMO, it's a good deal!