If your locker is working properly you will have 0% problem with it engaging 
The problem you might encounter is with the disconnect and the fact that it is vaccum operated. Any leak in the vac line to the disconnect or malfunction with the disconnect mechanism itself will cause the ring that slides over to connect the two pieces of axle together to not fully slide over or not slide over at all. If you get partial engagement of the disconnect ring you might srtip splines in the ring or on the shaft under high torque loads. If the ring dosen't slide over at all then you are not driving the passenger side, thus no pressure applied to it. It's REAL easy to pull the cover on the disconnect and see exactly how it operates. There will be a small amount of gear oil leak out so be prepared to catch it with a rag. RTV the cover back on when finished. You can get a cable that you manually push/pull to move the disconnect ring called a Posi Loc, costs around $150, or you can rework the disconnect ring and snap ring setup to have the disconnect ring connect both axle pieces at all times.
