Juan's 2004 100 series Landcruiser gets a front Harrop and Nitro 488R gears
(66 BIG pics loading)
January 4 2018

Juan shipped me both of his diffs from Alabama. The Harrop elocker can be seen with the Nitro product.
A solid collar will be added and new flange, also.
Both caps are marked in such a way that they cannot get flipped around or interchanged.
Start with pressing the old pinion out.
Now press the outer race out. The large inner race also gets pressed out.
Take this nasty looking CV axle seal out.
Both related bodies have been cleaned properly.
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All loose grit has been removed...mostly with a toothbrush size wire brush.
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With everything stripped down and clean, now the new Koyo inner race can be tapped in place.
Verified 100% seated down.
Same with the new outer race....100 seated down.
.076" will be the 1st try at proper pinion shim depth.
The new pinion bearing is pressed on with the 076 shim.
This is just for a paint test but I was curious ....and wanted to show off my fairly new torque measuring tool. A modest 8 in/lb of torque but just fine for this paint test.
Surfaces are checked with a file and no unusual burrs were found. Carrier bearings and the ring gear do need to be mounted up.
As indicated by my dainty grip near the hammer head, this ring gear went on easy. More of a slip fit.
71 ft/lb per the fsm and a little blue Loctite.
With the right widget, the new carrier bearings can be tapped into place.
Then the Harrop case is loaded in place and caps tightened up.
Re-using the existing washer plates resulted in 22 in/lb of total preload.....a little high but ok for a paint test. The backlash was about .008" so no issues there.
Drive side....the pattern depth seems surprisingly good and appears to be a keeper. Slight favoring to the heel but very little can be done about that.
Coast....appears to be at the ideal depth and well centered in the tooth.
Comet tail is not harshly tucked into the root.
Easier to see the comet tail trying to be a bit in the center.
Really easy to see it in this shot....the comet tail is indeed in the center and that means the pinion shim is in a "slight deep" state and leave it alone.
With depth established, now to install the solid collar.
On the second try, the perfect shimming was found.
This is a good quality seal made by THO in Japan so let's use it.
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"THO" located in Japan.
New flange style nut.
Pinion preload was verified with the torque wrench. A nice, smooth 10 inch/pounds of pinion preload.
DING! and this end is done.
For setting the backlash and carrier bearing preloads, a good selection of washer plates is a plus.
A fine tuning of the backlash while reducing the preload somewhat was the goal and .117" on the left side did the trick.
Backlash was recorded on approximately every other tooth.
The 4 bearing cap bolts were verified to be at 63 ft/lb per the fsm.
Good luck finding installation notes on the A10976 Harrop because there are none. Common sense goes a long way :) Some grinding on the caps.
Drill the 29/64" hole just about where it is shown here. Coat the rubber grommet with black rtv.
And it slides thru as easy as butter maybe.
Here's what the placement looks like on the outside.
This is a picture that Juan sent me of the nearly finished installation under his Cruiser and there is plenty of room for the connection on top. No interference issues.
Back to the testing of the Harrop....the measured resistance was 3.9 ohms.
Now the 12 volt battery test. No polarity on these 2 black wires so it does not make any difference which way it is hooked up.... just as long as it is hooked up.
Apply red to (-) and black to (+)....or is it the other way around It makes no difference. :)
With the electromagnet engaged, the ramp ring is held firmly to it. So turning the pinion flange which turns the ring gear results in the 3 engagement pins being pushed in the case. The locker is fully engaged now.
Notes are scribed on the ring gear.
Seals are next.
tap tap.
This CV side seal is fully in now.
Aluminum cover is clean....
...apply the FIPG.
Tighten the 9 bolts to 34 ft/lb per the fsm. One of the 9 is a hidden bolt.
My notes of the install of the 488 gears and the Harrop.
Ready for the trip back to Alabama.
Some fsm pages of the 8" IFS that I would like to share.