[Fot] TRactor Rocker shafts oil holes

[Greg & Alison Blake]

While disassembling the 5th rocker shaft I have ever disassembled in my
life this evening I had one of these moments where I question why things
are the way they are.  This time it is all centered on the fact that all
5 that I have taken apart show extreme wear on the bottom of the shaft,
but minimal to no wear on the top.  I am sure many of you are familiar
with the wear pattern.  These look to be the result of the bushings
cutting into the shaft and it makes sense that they occur on the bottom
because that is the loaded side of bearing surface.  The oil feed holes
in the shaft are located between the bushings on the top side of the
shaft which line up with the holes in the rocker arms I assume to splash
some oil onto the valve tips.  Why didn't they use oil holes on the
bottom of the shafts to lubricate the critical bearing surface?  Has
anyone tried this?
 
The new shaft that I have on the bench waiting assembly is one of the
readily available harden shafts.  Does it make sense to get that hard
chrome platted as well?  Anyone have a good resource for that service?
 
Probably over thinking this simple assembly.  Rollers would be nice.
 
Greg