Read it again. Don't make it a loose fit, just a medium or light press so you can get it apart without damaging the bearing. If you can get it apart or put it together by hand, you went too far, IMO. Front bearing can be lighter, sometimes they will go together by hand with all new parts. 1 or 2 thousandths make a difference in the pattern. I want to set it up with the parts I will be installing rather than have to fudge it. Tolerances on the parts are all over the place these days.

If you have a spare gear set that you carry to the track, it should already have been set up with the correct shims and bearing on the pinion ready to go.

When the pinion nut is tightened, the front race, spacer (or crush sleeve) and rear race and all pinched against the pinion head. You will burn the bearings up, weld everything together and twist the pinion in two before you turn a race on the shaft IF you didn't make it sloppy loose in the first place.

I only plan on removing a small amount and will still have a press fit or just set it up as is.......

I have found that if you are using a press that you are familiar with and have a "feel" for, you can tell how tight the press is with just a few pumps. If it's tight, you can still catch the inner race to pull it back off, rather than the cage. Don't slam the stuff together until you are satisfied with the fit. It should come off fairly easy with no deforming of the cage using a decent press.

I don't do it sloppy loose, but I don't want to need a press to put them on either. Been doing it this for 30+ years myself and my dad did the same. NEVER spun a race in a case. I don't hone bearings. I put the pinion stem or carrier in a mill or lathe and use a crank polisher, or just a length of emery cloth to take enough off to get the race on easily. This is the same way that Dewco sets up $5000 low drag centers. Good enough for them, good enough for me

So you`re maybe removing .001-.002.............

Not saying they should fall on and off. A light press fit, did mine and my brothers that way years ago. Both cars run T/brakes and no issues. Last time my 60 was apart, I changed gears, beautiful pattern but gears starting to get sharp. I will attribute that to 3500+lbs. and a transbrake on a street gear that was in the car for 10 yrs. The spool bearing surface that had been polished looked just like it did 10 yrs. ago when I did it. As did the pinion shaft. You don't just sand away til the bearing drops on. The way I see it, the gear change was routine maintenance in heavy car with a brake. JMO

I don't know why anyone would think the inner race would spin on the pinion shaft even if sanded down. The inner races of both pinion bearings are locked in place by the spacer and shims, which are sandwiched between the pinion gear front face and the pinion yoke.. Neither of which can change position.

If you want to go with a slip fit, it seems you would want to hone the bearing, not polish the pinion. if there does end up being an issue, I'd rather replace a single $40 bearing, than a $200 gearset. Besides, if you go too far with the bearing..... presto: you've got the tool you need to do it correctly.

This type of thinking goes against everything I was taught or did as a Millwright for 33 years. We never wanted a cup and cone style bearing to be a slip fit but to each his own. Carry on. Lol

This isn't heavy industrial machinery. Its a center section in a race car.

And what was the particular reason of no slip fit?.........or was it just because somebody said so........LOL!!!

Think about the bearings on the front spindles of all of our own cars! None of them are press fit. They're not even a tight slip fit. Just a slide on fit. And after a bearing burns up and gouges the spindle, how many of us have just filed down the burrs on the spindle and put another bearing on when there was no resistance at all. These cars are still running at pretty high speed at the track, and I haven't seen any front wheels fly off yet.

IMO apples to oranges. completely different type loads on the bearings.

comparing the load characteristics of a wheel bearing to a pinion bearing??? COME ON MAN! Set your pinion bearing up "loose" like you mentioned that wheel bearing and let me know how that works. I realize the "loose bearing" crowd isn't talking "wheel bearing loose"... but throw some sort of disclaimer on that comparison.

Ive never set up my own rear,but plan to next time.I've learned a lot with this thread.Thanks guys.

Think about what is being torqued down. The torque load on the pinion nut is holding an interference load between the two inside races and either a spacer and shim pack or a crush collar. As much as 150-250 lb. ft. But the turning torque is only 15-25 in. lbs. The inner race is what is locked down, against the pinion gear face and yoke.
All I'm getting at is that the interference fit of the pinion shaft and inner bearing race surface isn't "that" critical, and can be modified for easier setup without compromising strength.

So I ASSume now that I also need a smaller set up outer bearing as well as the inner since I may have to remove it again to get the pattern correct?

The outer bearing is pretty much a slip fit. Spool bearings on my Dana were as well. I've never run a slip fit pinion head bearing. I wouldn't want it sloppy but I'm not sure a tight slip fit would kill it since the rest are like that anyway. I would think the key is make sure it has enough preload. No preload usually leads to movement which leads to distruction.
Doug

I hone the inside of every pinion bearing when I build a rear end. You only remove .0005, then it still knocks off and on, not a slip fit. This let's you use the same bearing you set it up with.
I also measure the case offset of the carrier bearings so I know what to compensate when measuring off the cap pads for pinion depth. But I have depth mic's, gauge blocks, test indicators and a surface plate. Lol

Ok then, all are timken bearings so I would HOPE they would be the same and will find out as soon as I catch up on carb/car work..........thankxxx.......

Last question, are we checking pattern and what not w/dry clean or oiled bearings............