I am looking for some information, if you can help.

I have found a Detroit Locker, supposedly for a Dana 60. There is a spur gear machined on the OD of the flange next to where the ring gear mounts.

What is this gear for? None of the information I have found (Summit or Jegs catalogs, National Differential, etc) shows any variation like this. Also, how can I tell if this Detroit Locker is really for a Dana 60?

Thanks,

John