what are some of the signs of a

What are some of the early signs of a sure-grip starting to wear out ? I just installed a new set of 4:30 gears and used my original sure-grip (not cone type) and while putting the axles in I noticed the left axle will turn for an 1/2 inch then lock back up again the right side doesn't do it. it will do it in either direction. it feels like a clutch slippage thingy.