"Safety locking bearing nuts."

[Franklin-Madman]

While helping a friend research a particular old engine, I came across this note in an OX5 Handbook from 1925.  It reminded me of something discussed in the Franklin community and indeed it is in concordance with advice given on The H.H. Franklin Club's website concerning the main bearing nuts and rod nuts on Franklins.  I transcribe the OX5 wording here in full as a refresher and to spread the word. (The OX5 was a popular Curtiss V-8 Aeroengine of about 90 HP.)

 

 

 

Safety locking bearing nuts.--- In regards to the proper placing of cotter pins in the bearing nuts, there is much argument, but the following points stand out preeminent:

 

First.--- No nut must be turned backwards or loosened to the make the cotter-pin holes line up.  If it can not be turned forward to the next slot in the castellation without straining the threads, the nut should be removed, and the bottom surface filed a very small amount.  This process should be repeated until the nut will turn nicely up to the slot in the castellations.

 

Second.--- The cotter keys must completely fill the holes in the stud bolt.

 

Third.--- They must be so placed that they do not wiggle or feel loose in any way when touched by the fingers.

 

Fourth.--- The cotter keys must not be bent over with a hammer, but should be bent with a pair of round nose pliers.  Bend one side of the cotter key up over the nut and the other side downward, unless in particular cases it is found to be distinctly better the bend both sides of the key around the nut.

 

[End Quote]

Edited July 10, 2015 by Franklin-Madman (see edit history)