8-3/4 489 pinion shim help

[73cudakid]

Im setting up the pinion bearing preload in my 489 case. It has new beraings, with the old races. Im setting it up with a solid crush sleeve and shimming it to achieve the proper preload (14-19 in-lb). When i use an .010 shim it is at roughly 8 in-lb and when i use no shims im well over 40 in-lb. Common sense would say try an .005" thick shim, but nothing in the shim pack is that thin, the .010" is the thinnest. Is the 8 in-lb going to be a problem or is that too light.
Thanks in advance

[tactransman]

Why would you put new bearings on old races?  You can file the spacer shorter if you need to and use the .010 shim.

[quagmire]

Bearings and races wear together, mix matching them is a big no no.  They should always be replaced together.  It could cause early failure, as the old parts create their own wear pattern even if you cannot easily see it. 

[72cudamaan]

New bearings... old races          Baaaaaaaad! Do it right, put in the new races.

[73cudakid]

Picked up the new races. Should have them installed during lunch break tomorrow hopefully.

[73cudakid]

Finally got it all together. Wanted comments on the gear mesh. I was at 18in-lb on the pinion preload with new bearings & races. Solid crush collar filed down to get the right preload. Backlash is at .008" at 4 locations on the ring. Does that gear pattern look good to go. Just looking for some input since this is my first one i set up.
Thanks
Dave

[quagmire]

Did you load the diff with a pry bar?  It looks like it needs to move up more towards the end of the tooth, but it is a little high too.  I think you need a thicker pinion shim and maybe even a little less backlash.  If you didnt load the diff while taking the pattern you need to redo this again.  It will really affect the pattern.

[73cudakid]

I didnt load it with a pry bar, just pushed against the ring to put a load on it. I will try it with a screw driver or prybar this weekend and see how it comes out then.

[quagmire]

Make sure you push on it prying down, not side to side.  Under load the diff tries to twist, thats why you need to put that load on it.  Don't be afraid to put a fair amount of pressure on it.

[73cudakid]

Does it matter if i push from the top or bottom?

[quagmire]

Yes, you should push with a downward force from the top.