Over the weekend I tried changing the front wheel bearings on a friends 2012 Impala. The bearing is a complete assembly, so I was hoping it'd be a pretty easy job. But when it came time to push the axle through the hub, it just would not go! I've changed a few axles on FWD cars before, and those have all just pushed right through with maybe a tap of a rubber mallet. So we went to autozone and rented a FWD hub puller. Large impact with 150 psi, still nothing. I was starting to get a little nervous, with that much force on the tool, I was thinking it could fail and send parts flying. Tried heating it with mapp torch, nothing. Tried the other bearing, same results. So I had to give up temporarily. Next step is to pull the whole knuckle assembly, and try to press it out with a 20 ton shop press. After looking on youtube for a bit, and I now know how much of a challenge these things can be!