OC-12 differential markings

[Thiokol2track]

Does anyone know what the 4 digit number means that is stamped above the casting # on the oc-12 rearends?

 

[Thiokol2track]

This is on the back side of the housing an inch or two down from the top.

 

[Snowcat Operations]

PM snowcat pat. When he gets on he will see the pm. He doesnt post allot and may miss this question. I bet he will know.

 

[Snowcat Pat]

I spent some time reviewing rebuild photos and I don't know what that number is but it for certain isn't a date, I have one photo that the number is 1955. I believe it to be a serial number. On old machines the number is smaller and on newer machines its larger. Thats my only clue.
-Pat

 

[mkntrakes]

Are you talking about the had stamped # ? If so this is the width of the housing this # is used to set up the differential the drop boxes also have a hand stamp # and are used in the formula to establish proper shimming of carrier unit

 

[Thiokol2track]

I would not have known if I hadnt asked ! Thanks mtntrakes!!

 

[Snowcat Pat]

For the sake of clarity here are two pics of the back of a OC-12 case. The four digit number Thiokol2track asked about (top) and the case width number mkntrakes mentioned (bottom). Pages 4-18 and 4-19 in the manual explain the purpose of the case width numbers.
-Pat