Outside the box -- sort of

Put a line through the center of the prop shaft. Put another line through the center of the shaft between the joints. The angle corresponding to the change of direction going from one line to the other is the joint angle. If I understood note #13 properly then that angle is around 37 degrees. I wouldn't count on an automotive outer CV joint lasting indefinately at that type of angle. If my memory is correct 37 degrees is around the limit or beyond for most CV joints.

 

DCockey

Thanks. Looks like I will have to do more research and/or design modification.

 

do not know if this is any help. http://www.cvaxles.com/marine.htm

 

Rasorinc,

Thanks. I found them before and they looked difficult to deal with... compared to ordering an off the shelf unit. Also, has the feeling they spell boat --> B$O$A$T$. I do want quality but I gotta have some money left for diesel to turn over the engine that drives the prop.

I did find a 36.5" long unit for a 2002 Chevy Prizm at http://www.carpartswarehouse.com/carparts/2002/Chevrolet/Prizm/Drive_Axle.html , in case anybody needs one. $85 plus $0 Core. Free Shipping! I'll bet if I buy two spares I'll still come out ahead.

Now all I need to do is find out the maximum designed angle for continuous operation.

Anybody got some thoughts on how or whether to try saltwater-proofing it?

 

Go to the 3M website. They have a marine division and when I contacted them re: adhesive, they got right to me and were very helpful. They have tons of products. Just a thought for you can you chrome it? Industrial hard chrome like on engine drive shafts and cams. Or some other type of plating.

 

Prop shafts in all racing outboards ( over 60hp ish)and sterndrives are carbon steel and they are chromed to stop the rust.
Works moderately well

 

I cannot confirm nor deny that. There is an urge in me not to take things for granted just because the general opinion says something cannot be done. But I did study mechanical engineering and electronics for several years, so I am a bit biased when confronted with weird ideas.

Car manufacturers use a thin paint layer to protect metal parts so they survive the warranty period under normal conditions. But they accept corrosion as a fact of life.
There is a vast difference between being subjected to a bit of road salt followed by rain and being immersed in seawater for a length of time.

 

true but five dirt cheap parts are bound to outlast one hugely expensive custom part

 

If I recall right some people made these CV joints for their boats from car parts long before any marine CV joints were available..