If I manualy lock the front axle I can drive off road with it locked, But not on the pavement. It is hard to get a deffinate answer on this, And I just don't know that much about how this works yet. your imput is appreciated.

 

it doesn't matter. but for better fuel economy, i'd unlock it for street.

 

i ended up swapping in an a different dana 30 front end with the vaccum lock,after getting my jeep submerged in a creek and got sand in the front end and it ate up my pinion bearings,we took the vacuum locker apart,locked it and put it back together with 80 cents worth of washers from ace hardware i drive it on the street but i dont care for the vac lock front end due to the 3 piece axle on the passenger side,that would be a bad thing to break offroad.

 

Go to a bone yard and find a 92+ cherokee and pull the right side axle shaft out u-joint and spindle. Get a piece of sheet metal and some RTV take out the posi lock cable housing and trace it's shape onto the sheet and cut. Drill four holes in it and bolt it onto the hole in the axle with RTV and slip in the new shaft. Problem solved.