Turn signal assy

1988 Chevy Silverado 350 Engine 700 Tranny 2WD I just changed the turn signal assembly and horn components on this truck. Everything came off okay but putting it back together is a problem. There is a spring that I can't completely compress. I have no schematic but it seems that something must be out of order going back in. As I compress the assembly I get it all but about 1/8" before it completely stops moving to put the "C" clamp on to hold in place. I've done one before on a similiar truck and it wasn't nearly this hard. Any help would be appreciated