Easiest ball lower ball joint I've done. I froze the joint over night, and heated the control arm with my heat gun. Not even hot enough to sizzle spit, but hot to the touch. Ball joint went in so easily! When I was doing front end work for a living, I used to keep lower ball joints in the freezer, never tried heating the arm up as well. Now I'm convinced.
you might want to check the fit. I've had more than one control arm distort and lose its press fit. one tap with a hammer and it would fall right out. fwiw, back when I was at the machine shop we heated things to ease pressing all the time. I was taught that the metal doesn't expand much at all until it begins to turn blue.
A few rules of thumb... Aluminum and steel will expand the same amount, just at different rates. At 500F (depending on the grade of stock etc) you can just about rely on .001 - .0015" of expansion per inch of diameter. Turn a bearing blue, you may as well throw it away and get another. Spit sizzles at 200F at sea level. As I said, these are "rules of thumb" and not cast in stone. ws
