gear install on ford 9"

I installed 4.86 gears in my ford 9" today but ran into a problem. I put the pinion support into the drop out and started to adjust the backlash but the ring gear is touching the pinion stub shaft bearing part of the case before I get the correct backlash set. Has anyone ran into this problem? Should I grind off part of the case till it clears or do I need a new case?

BTY the axle is out of a 79 bronco. I also installed a detroit with the 4.86 gears. And I got everything from Randys ring and pinion if you need to know.

Some cases require that you carefully grind the clearance for the new gearing. Thats why I use 4.57 instead of 4.56 gears when regearing a 9". The 4.56 requires grinding and the 4.57 does not. Hope this helps.

Simon

I've got a 9" and 4:86's, I had to grind a little to make the gears clear