When doing a gear swap – ALWAYS change the bearing AND the race.  Seems like a reasonable thing to do right?  Well, first time in we didn’t pop out the race – we just pressed on the new bearing – BIG mistake.  I knew better but didn’t change the race anyway.  Regardless of the bearing (parts store, Ford or otherwise) I should have changed the race too.  I suppose a parts store bearing might have fit the race that was in there (motive gear I believe) but always change the bearing AND race at the same time – they wear and seat to each other so mis-matching is NEVER a good thing – again I knew better.

To add more to this story, turns out the new style Ford pinion bearing is in fact a special piece, and their race absolutely HAS to go with their bearing as seen below.  Luckily I didn’t drive far and the gears were fine.

Symptoms were having to remove ALL the pinion depth shims (which you should NEVER have to do) – then having to move the carrier far to the left just to get the backlash close.  This threw off the coast pattern (which we didn’t even look at) – causing the rear to be super noisy.  Would have blew it up for sure had I driven on it more than I did.

The fix was to use the proper Ford tool to set pinion debth – then of course to use a dial indicator to set the backlash (.08 – .12).

Lesson Learned!