D5 96J steering clutch

I have one steering clutch out of my D5. I need to get the 2 cast pieces apart so I can change the throwout bearing. I made a puller and tightened it up and hit the puller with a sledge hammer and nothing... Then I tightened the puller more and broke one of the bolts. Any advice to get it apart... Heat???

The curse of Caterpillar tapered splines. A hydraulic press is almost a must. I have a 40 ton model and it works it to do the 9u D6 clutches. Heat will help, where you using a grade 8 bolt.

To back what Ray wrote, I have an OTC threaded puller rated for 17t. I also have a hole ram at 20t. The steering hubs for the D2 are supposedly on at about 15t. The OTC puller didn't even look like budging them. The hole ram popped them off just shy of 17t (before the pressure dropped)