Harold's 2018 Tacoma TRD 8.75" rear 3rd gets Nitro 529 gears
(82 BIG pics loading)
June 30 2019

Harold's actual 2018 Taco TRD as shot right at the Camelback dealership.
Color: Inferno Orange. 3.5L 24 valve DOHC, 6 speed automatic transmission. Overdrive is a fantastic .58 Has 33" tires as shown right now but will soon see 35"
Harold's 8.75 rear e-locker 3rd is on the bench with the stock 3.91 gears. Nitro 529 gears and a genuine pinion seal shown....but no bearings. On a 2018 or 2019 Tacoma, it can be argued that the bearings are already still like brand new.
Nitro 529 gears and a genuine Toyota pinion seal. The pinion shaft is massive.
The only other thing that might also be replaced is the blue connector (elocker connector). I keep a few always in stock.
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Go to the dealer and the black connector on the left will run $100...... The blue one is about 35.
That connector really is blue. I suspect this is the original gear oil from 17,000 miles ago. Harold will be using Valvoline Full Synthetic 75W-90. Synthetics can be left in much longer, they will lubricate better, they will run cooler, and they will not leave blackish coatings on the internals.
This is the new connector that I suspect I will be using.
Sure enough, could not get this plug out without breaking the delicate tab off the other half. It's in there so tight that , even though this is a 2018 model, the connector was being stubborn and the other half had to be destroyed. And that's exactly why I keep a few "blues" on hand.
Even with the tab broken off, the plug would not pull out so "operation destroy" proved to be very effective.
The new blue connector shown plugged in 60% of the way.
With the minimal $35 cost, it's just not worth the fight to save the old connector.
No destruction is needed for removal of this one. The differential case should be removed first then the black connector can easily be removed.
But first, a quick check of the total preloads.....looks like about 10 inch/pounds.
Differential case in the process of being removed. The 2 bearings caps are removed first.
The washer plates were almost loose enough to remove by finger power. When I'm done with it later, it will be much tighter.
ding ding ding and out it comes.
Carrier bearings in nice shape.....as they should be with a low 17k miles on them.
Other side in fine shape too.
Now, let's get this thing out of the way.
Remove the 6mm bolt with a 10mm wrench.....
Out it comes.
Getting the pinion out.....the cordless impact wrench has plenty of torque for this.
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Pushing the pinion out.....probably less than 1 ton of actual push is needed.
Pre-cleaned the flange....and you can see that it's almost like new with the tiniest of grooves.
OEM is hard to beat.
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Outer bearing in beautiful shape.
The big inner bearing is excellent.
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Now to remove the 12 ring gear bolts.
With a fresh battery, the cordless took all 12 bolts off. The factory used a good red loctite on the threads.
High speed bench wire wheel cleaned the debri off the bolts just fine. Starter fluid removed all the oils.
"old" 3.91 ring knocked out.
Nitro 529 ring ready to go on.
The Nitro ring tapped on very snug.
92 ft/lb with red Loctite.
The big pinion bearing was swapped over to the Nitro 529 pinion.
Pinion is mounted in diff carrier and only tightened enough to offer some pinion preload......
.....roughly about 9 inch/pounds worth.
Differential case is re-installed with the factory washer plates. Backlash was measuring close to zero.
Did some mental math and changed out the washer plates.
Perfecto......now was measuring .0055" at the tightest places.
1st paint test....DRIVESIDE.....looks shallow.
COAST......shallow.
Comet tail.....hugging the root too much so that says shallow for the ring gear.
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Now to push the pinion out again to add some more shim to the pinion.
Inner big race. Marked it so I can keep the orientation in the exact same spot.
The pinion shim is located behind the inner race.
The factory shim thickness measured at .0765" roughly.
Removing the inner pinion bearing with the 12 ton Harborfreight press.
Going to relocate the shim to the pinion head. There are certain advantages to doing that.
.083" is .0065" thicker than the factory .0765" shim.
Skipped a few steps...pressed bearing on pinion and tightened pinion nut enough to offer some preload.
DRIVE....Much better. Looks "slight deep" which is my favorite condition.
COAST....looks wonderful.
The comet tail no longer deep in the root....almost out to center.
The tail says to leave it alone.
The factory crush sleeve has thicker sidewalls then the aftermarket ones. It's a bit more stout.
Because we no longer have a thick .0765" shim behind the race means that the old crush sleeve is now too long. Too long by about .076" so I shaved off .050" and still have plenty of sleeve to crush.
I have noticed that the factory sleeves fit the pinion shaft "better" and do not wobble around nearly as much.
Testing the fit of the new oem seal. We already know it fits great but this is habit.
Lining it up.
Tapping it down smoothly and evenly.
Apply gear oil to all the contact areas of the flange.
Not shown but there is anti-seize on the pinion threads and the bottom of the nut. It makes crushing the thick sleeve possible with this cordless impact.
Even with new gear oil splashed liberally on the bearings there was still a little stickiness in the readings but seemed to be around 7 or 8 inch/pounds.
DING!! and this end is done.
Nice and smooth.
Good time to put the lock sensor in now.
A dab of petroleum jelly lubes up the o-ring.
Then the differential case is loaded......then the carrier bearing washer plates.
A little thicker washer plate on this side adds a little extra backlash and preload. Fortunately, these are high quality washer plates and can take some good hits. The 2 bearing caps are mounted and torqued to 84+ ft/lb on the 4 bolts.
Kinda going back and forth but now is a good time to apply medium strength Loctite and 6 ft/lb to both connectors.
The black plug pushed right in all the way and heard the retaining tab lock it in place.
Backlash checked and recorded on every other tooth.
Date coded......
A snapshot of the assembly notes.