Purchaing an 05 axle, it is missing one lockout. I knwo zero about super duty axles and their parts. Please excuse my lack of knowledge.

are they vacuum actuated? do people replace them with manual units? how dependable are the vacuum units?
What do I need to make the vacuum units work with my 91 conversion?
any info appreciated!

if possible i would like to retain the factory style vacuum actuated. Would be nice to not have to get out of the truck to get into 4x4

 

The only drop in replacement hubs I know for that year are Motorcraft replacement hubs. They are not cheap but the 99'-04' Motorcraft hubs are not cheap either.

The ESOF system uses vacuum to lock the hubs. The trucks with manual t cases don't have vacuum operated hubs, manual only. There are several aftermarket manual hubs available for the 99'-04' trucks but not the 05'up trucks.

You should be able to see the vacuum port on the back side of the knuckle. When the switch is turned vacuum locks the hubs using a solenoid and an electric motor shifts the t case.

More Information for DORMAN 600402

 

ok, so just gotta rob a lockout from the JY i guess

 

A new one from the dealer will probably run you at least $300 FYI.