yep, putting the shaft in the freezer will make the shaft shrink, and if possible put the bearing that goes on it in an oven that will cause expansion, but make sure you get bearing where it goes b4 everything cools or warms because it will be there.
when i used to work in a machine shop and we rebuilt gear boxes, we had this tool that was a piece of square stock about an inch square that had a u shaped stand and the 1'' stock sat on top of the u....
you picked up the piece of stock and slide it thru the bearing and replaced it on the stand, plug it in and turn it on and it became a electromag that vibrated and it would sit there and humm and it actually rotated the bearing, just because of the vibration i guess, but after about 20 min the bearing would be so hot you couldn't touch it, you had to use gloves and take it off slip it on the shaft to where it goes pretty quick, hold it til it cooled alittle and it would shrink down and stick itself on the shaft. i mean tight!! tighter than you could drive it on with a bfh and a bdp(bull dic punch), without the chance of harming the bearing.
i have a toaster oven in my shop that i use to heat parts that are (i'm at a loss for words, i can't think what it is called, i know it starts with a c...and means its when two things are held together just because of tolerance. its a common term. compression fit, that don't sound right tho, please someone put it out there or it will bother me the rest of the night)
but yea its physics, works on everything except water, which contracts as it cools also, but once it hits 34 degrees it starts expanding, where as all other matter as it gets colder the molecules get closer together, and as things heat up the molecules become further apart!
man what is the word....contact fit....compression fit, maybe, sum1 please straighten my still slightly altered brain, constriction fit....dam it man, this is why you don't drink while working on your rig, wait til afterwards!!