No, the 235 (as I have also just learned) has 4 different main bearing diameters. They are listed in the manuals. I think the reason for the step is that they are bored and honed by a single tool (probibly from the rear as that is the largest opening). You need to step the diameter of the bore holes to allow the tool from the bearing in front of it to come out without scratching the newly machined surface.
Journal Diameter, Inches:
Front: 2.6835 - 2,6845;
No. 2: 2.7145-2.7155;
No. 3: 2.7455-2.7465;
No. 4: 2.7765-2.7775
I copied these from another site. They are stepped like the cam bearings are. The reason cam bearing are stepped is to allow a tool to pull them out.
Holding a half a thou on a tight machine is commonplace today. Setup is the killer. You have to use 3 surfaces to locate a 4th... to a .0005 or less tolerance.
Last edited by pfarber; 03/18/2014 4:14 PM.
