Tim's Front Hi-Pinion 8" Screams Just As Loud
(50 BIG pics loading)
AUGUST 19 2016

Front 3rd is mounted in the fixture.
Misc pieces are removed and placed off to the side.
Nothing too unusual with the backlash measurements or the preloads on the bearings.
A paint of the drive side shows this diff has the same extreme shallow condition.
Coast just as bad.
Shown here is what a flat surface with 100 grit will do to remedy a badly schingered wheel. A before shot is not available.
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All 10 ring gear bolts were verified to be 70 ft/lb and they were.
Flanged was removed and pressing out the pinion here.
Removed the flange to discover the splash guard was in upside down. The ends of the fins must have been smacking the rollers on the bearing with a very loud noise.
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The rollers are in very good shape still. Does look like new bearings were used.
Tried to clean it for better presentation but that did not work out well :)
I should have used starting fluid and a clean "microfiber auto cloth" because it would show off better that these rollers bearings are really in excellent shape.
The pinion races do not match that.
This is the large inner pinion bearing....rollers look almost new.
Race might have a little more wear.
Pressing the pinion bearing off.....
Where is the pinion shim?
Going to try a .0775" shim and see what happens.
Pressing the bearing on with the shim.
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Then to mount the pinion assembly in the diff carrier.
Get the backlash set to an acceptable number......
1st paint reveals that the pattern is too deep.
Coast.
Teardown again.
This time .071" will be tried.
Looks like "exact depth" and needs to be a little deeper. So I know that .0775 is too deep and 071 is exact so if I go 073 then we will be "slight deep" and good to go.
Coast.
The original crush sleeve can be re-used because it was never crushed properly in the first place. Assembly can happen now without a final paint check. The splash guard is installed right side up this time. A new seal is used.
Pinion flange is installed.
Crush sleeve had to be crushed another 1/8 turn before 4 in/lb of PPL was observed.
A mild 4 in/lb of preload was measured.
DING and this will never loosen up on its own.
The 4 bearing cap bolts are torqued to 70 ft/lb.
Backlash is recorded on every other tooth....over 20 measurements. I noted the minimum BL to be .006".
This is the preferred condition....slight deep.
Coast
Total preload is measured at 13 in/lb.
ARB seal housing assembly is installed and the 2 tabs are now torqued to 10+ ft/lb.
ARB is checked for leaks and none found.
Routing is confirmed.
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Notes are noted.
The original double box did very well and is still re-usable. The lip of the diff did ding the bottom and leave a touch of oil there but no issues with that.
Taking extra precautions to cushion the entire diff on the bottom.
This is good.
Ready for Fedex now.