Putting tires onto axles I have vintage Lego sets (1970's and '80's).  I absolutely cannot get the tire to fit completely over the axle.  Should I try grease or hot water?  I know this is the correct tire because I have some that already have the tire over the axle.  Please help!!
From my experience with tires you mention is that they don't sit symmetrically when placed improperly as they should be. Try going around the tire and pulling it slightly outwards as well as twisting a little from the side with larger outside diameter to center.

This happens with newer sets also.