I've been trying all afternoon to get the new Timken bearing that came in my rebuild kit on the pinion gear I want to put it on and it won't go past 2/3 of the way down with a 12 ton press, I even tried putting the pinion in the freezer and bearing in the oven and still no luck. I also tried sanding the contact surfaces of the pinion and bearing with fine sandpaper to make sure there weren't any ridges or debris to keep the bearing from going on and still no luck. Other than REALLY heating the inside of the bearing up with a torch to expand it I don't know what else to do. How hot can you get these bearings before you have to worry about ruining the temper of the steel?

 

I forgot to add I also lubricated the bearing and pinion with a light oil before I tried to press it on to help it slide on.

 

Is this the head bearing or tail bearing?

As a last resort, I usually use a brake cyl hone in the bearing shaft bore.

As far as the heat, put some oil on it. Heat it until it just barely starts to smoke. That's around 400° with most modern oil. Won't hurt the metal.

 

It's the main, larger bearing

 

That's the "head" bearing... think of the pinion itself as looking like a tadpole...

 

Well you learn something new everyday! I left the pinion in my freezer for three hours or so and the bearing in a 350 degree over for about an hour and when I took them out the bearing just dropped right on the pinion. I can't believe I spent several hours trying to muscle it on with my cheap harbor Freight press. I guess sometimes you have to work smarter and not harder.