Colby had attempted the install and was having some issues so he boxed up
both diffs and sent them to me. The box broke open in one of the corners and
some stuff was lost. Carrier bearing cups,pinion washer, and a pair of bolts
went bye-bye. No biggie as I had some back-ups. These are 4.88 US GEAR brand and
properly installed will last longer than the rest of the truck. Being that these
are going in the front, a crush sleeve is ok to use.
First, I have to remove the pinion and try a starter shim.....I tried the
brass punch but it was too solid in there so.....
I eased it out with the 10 ton press. This press has seen so much use.....it's
paid for itself 10 times over.
These bearings go in the garbage as they are no good without cups......A
good used set shall suffice.
The used ones are Timken.
I roughed up the surfaces, cleaned them with starting fluid, and applied some of
this stuff. It's like a "loc-tite" but designed for non-threaded
surfaces.....prevents spun bearing damage.
I also removed the ring gear and filed the surface smooth to minimize run-out.
Loc-tite is the way to go.
Cross-tightened them to 70 ft/lbs.
Back to the pinion....I chose to use a .098" shim for starters. These
micrometers offer some real precision....I have a cheapie set of 14 dollar
calipers that I like to use also.
The press easily lands the bearing down onto the shim.
The races were already installed...but just for grins, I used a soft punch
to make sure they were seated ....... and I found they were not. I bet that was
causing you some grief, Colby ;)
edit---Best to stay away from all punches...use an old race to evenly "pat" the new race down.
I skipped ahead a bit here but basically re-installed the pinion without the
crush-sleeve but tightened the nut just enough to offer some pre-load then
installed the carrier with about .008 backlash. I painted the teeth and placed some
drag on the ring-gear while turning the pinion. This gives a good paint. This is
the drive side and is too shallow with .098. I don't care so much about where the
pattern is from top to bottom as oriented in the above pic.....I care alot about
the "left to right" how deep it is. The "up-down" location of the pattern is
influenced via backlash but that influence is very limited.
I got a little carried away and made a big change in shim here.....I re-shimmed to
.108" (a 10 thou increase) and now it is too deep....so the right mesh is
somewhere between 098 and 108.
Re-shimmed to .103 and this is more like it. This is the drive side and
using the normal .008 backlash. I have very little influence trying to push that
pattern "up" closer to center....actually, under torque the pattern dynamically
moves in that direction. It moves toward the center which is a good place to be
under conditions of high torque. Now since this is the front ring/pinion, the
only time this side sees contact is with tranny in reverse, for what it's worth.
This is the coast side....this is the side contacted while going forward.
So now that I have the right pinion shim, now I get to take it down again to
install the crush sleeve......sure is nice having the electric impact....for
everything I do in my little shop.
Now it's just a matter of dropping the new crush in there...then the
bearing, seal, yoke, and nut in that order.
I used Ultra-Blue RTV on the metal seal lip and some good grease on the rubber
seal to prevent a dry start. Using a 600 grade fine sand-paper, I wet-sanded the
yoke surface to get the best possible seal.
It only took 1 arm to crush the sleeve down....
After all the slack was out of the yoke, I very carefully continued to crush
the sleeve until I reached about 15 in/lbs on the pinion pre-load measurement. I
also used the blue Loc-Tite on the main pinion nut and staked it as well....that
ain't ever gonna loosen on it's own!
I then re-installed the carrier and made sure carrier bearings were very TIGHT and
maintained the .008 back-lash. How many diffs have exploded because the carrier
bearings were only snugged finger tight I am not certain. One diff ready to head
back to Bountiful, Utah. I will also box it....and I will make it UPS proof ;)
GO TO REAR INSTALL HERE