Kazuma LSD and 4.56 Nitro Gears for Tyson's 2003 Tundra
(38 BIG pics loading)
May 11 2015

Tyson is in North Carolina and his 03 Tundra is called upon to do some unusual duties.... like pulling a 24' gooseneck trailer with horses inside thru the wet, soggy and sometimes mucky grass.
Excellent traction is a must for this useage in this 1st gen 2WD Tundra with 4.7L 245 horsepower V8 with A340E auto tranny. In the differential is a limited slip but it's the weak factory version and very worn out.
As received from Tyson. I've seen these extra heavy duty totes at Home Depot and also at Lowe's. I think they were priced at about $15.
115 pounds.
The spare open Tundra 3rd, Kazuma LSD, Nitro 456 gears and the master install kit. JustDifferential 8.4" Nitro Gears JustDifferential 8.4" master kit
Manufactured by Eaton for TRD, this lsd is much better than the OEM version that Toyota sometimes puts in the Tundras. Here's some of the reasons why.... Kazuma LSD
Cabe Toyota has them for $299 Cabe Toyota
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8.4" master install kit
4.56 30 spline Nitro Gears...very beefy thick pinion shaft.
Teardown starts by removing the cross-brace.
The 12 ring gear flange style bolts had some sort of oem high strength loctite on them so the electric impact got a work-out getting them off.
The ring gear was a very tight fit.
Red loctite and 92 ft/lb on the 12 bolts.
Carrier bearings tapped on very tight.
The "carrier" is now put aside and the pinion end begins.
New outer and inner bearings are waiting. But first...
...the old pinion and races have to be purged of the differential.
Old race comes out.
Use the same chisel and tap out the old inner race. The pinion sham is behind the race on these 8.4" 3rds.
The original .0795" washer plate is re-useable if one takes the time to remove the damaged material.
Notches were ground out such that I can tap the race out in the future to change pinion depth with no damage.
I'll add .005 to the oem .0795" plate. I know the Nitros need a little more than the oem value to dial in the best pattern.
The 30 spline OEM flange is an amazingly tight fit over the pinion splines so I like to use the press to ease the flange down 95% of the way. Then tighten the pinion nut with the electric impact until about 20 in/lb of drag is felt.
The Kazuma is loaded in place...start with the oem washer plates and see if the backlash is close enough for a paint check. I observed that it was not. Was only measuring .001" backlash.
By adding .008" to one side and taking the same amount off the other side, the backlash increased by about another .006" giving us the green light for a paint check.
close but could be deeper.
Right in the center but too soft....could be deeper.
Teardown time. Take the .005" shim out and replace it with a .008" shim.
Now is a good time to check how snug the lip of the pinion seal fits. Nice. Not shown but a solid collar was also installed.
With the thicker pinion shim installed and the solid collar, now it's time to tighten the pinion nut til about 9 or 10 in/lb of drag is measured.
I was able to tweak it in to a nice 10 in/lb.
Ding the nut and done.
I added another .005" on this side shown and .003" on the other to increase the backlash and also the pre-loading.
Backlash was measured on every other tooth. The minimum was noted to be .0065"
Combined preload was 19 in/lb. Pinion preload was previously measured at 10 so that means the carrier bearing preload is 19 - 10 = 9 in/lb
Last paint check and the drive side looks to be my preferred slight deep depth. Well centered too.
Coast..proper root contact and slightly favoring the heel.
A double-check...The FSM says 83 ft/lb and I like the sound of that number too :)
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