Kazuma LSD for Eric's 2000 Tundra
(44 good size pics loading)
JUNE3 2013

Eric enjoys his Tundra in the desert.
Some of the best campspots can be a very long ways from the main road and good traction is a good thing out here.
Cabe Toyota has these high performance, 3 pinion, 400 ft/lb pre-tensioned LSD's still in stock....at least for awhile.
The 8.4 is on the test fixture. Since this 3rd has 150k miles on it, it was deemed a good idea to add new carrier bearings at the same time.
Nice machine work.
I count 3 pinions. The OEM factory version has 2.
I'm not disturbing the pinion end....only the backlash and Carrier Bearing Pre-Load (CBPL) need to be adjusted/maintained. Here, the backlash is measured and recorded on every 3rd tooth.
These are basically factory undisturbed readings.
Not required but a quick pattern check shows a good one. Here is the drive side and it does look excellent.
Coast is excellent also.
I had to dimple mark this one as I didn't see any factory white paint mark.
The Makita 6905h electric impact makes quick work of these bolts.
At least this time the washer plates were in somewhat tight. Finger power was not enough to remove them.
The micrometers accurately measure the washer plate thickness. These numbers are written down because I will probably add some thickness to one or both in the end.
With the stock case out, I can clearly see the nice drive pattern on the very long pinion tooth.
Now to remove the old carrier bearings.
Looks like July 31 1999....390 ratio.
The OTC-4520 bearing puller easily removes the tight carrier bearings. This tool has paid for itself many times over.
No reason to throw the old bearings out.
Cut the cage off with a dremel drill.
Chamfer/soften this edge with a flapper wheel and keep it near the hydraulic press.
Back to the ring gear bolts. These bad boys are often on unbelievably tight. Here, I'm using welder gloves to cushion my hand to prevent bruising from the extreme push required to break the bolts loose.
This 17mm wrench has the edges ground off to increase the contact surface with the low profile boltheads.
The factory is using a high strength thread lock.
The ring is off.
Surfaces are checked with a coarse file. All looks good.
I wrote down some 8.4" specs that were in the FSM. They want 92 ft/lbs on the 12 ring gear bolts. That's a good amount.
Red loctite is applied to the clean threads. One of the easiest ways to clean the threads is to use the 4000 rpm bench grinder with the wire wheel attached. Makes them look like brand new.
Why scratch up the well machined Kazuma by placing it in the sharp jaws of a vice when I can use the tension of the press to lock it in place while I tighten the 12 bolts to 92 ft/lb.
Here, I am using the salvaged old bearing pieces to assist in pressing on the new KOYO carrier bearings.
The Kazuma is ready for installation now. Maybe a few drops of gear oil on the bearings at this point wouldn't be a bad idea.
Before installing the Kazuma, a quick pinion preload measurement shows a reasonable 4 or 5 inch/pounds start torque which is very good for 150k miles on the bearings.
Original washer plates are installed. They went in fairly tight. The hammer was required to tap them lightly in place.
I have found that the lack of the brace can effect the readings so it's best to place the brace in and snug down the 4 long bolts.
Not bad...I am feeling a good amount of resistance....which means the CBPL is good.
Backlash is sampled around the ring and it's a little tight at about .003" so I can correct that while adding some additional CBPL at the same time.
Should be the last time I remove this brace.
I'm adding a washer plate on the ring tooth side that is almost .004" thicker than the oem plate. That has the effect of increasing CBPL and also increasing the BL by about .002" more.
I could feel the extra .004" thickness....took a little more tapping to get a full seating of the washer plate.
The electric impact can snug the 4 bolts lightly.
These caps are torque to FSM specs of 83 ft/lb
I measured the total preload....combined pinion and carrier bearing preload at 13 in/lb start torque.
A few pics might have been left out here.....Backlash was quasi-averaging .005" ...measured on every 3rd tooth....a few that were as tight as 004 and few on the upper side at 007. This pretty much duplicated exactly the recorded backlash values before teardown....as verified on the notes shown below.
Notes taken of Eric's Kazuma install with new carrier bearings. The pinion end was not disturbed. There was nothing wrong with it. Eric did the right thing and supplied me with new, fresh carrier bearings with the Kazuma. This should give a very long life....and good all-around strength as the bearings are tight and the ring gear will resist deflection.
Done :) Update----6-8-13----Eric sent me this email...cut/pasted... "I finally got out Sunday to give the Kazuma a field test. I have to admit, it works better than I expected :). Engagement to wheel with traction happened very quickly with no noise, vibration , etc. and even with (traction side) wheel stuffed really hard and opposite barely contacting the ground it delivered full power. I believe the conservative addition of Sta Lube additive has enhanced the performance. Hopefully, it does not accelerate the LSD clutch wear too much. I filled diff to 90% full and drove truck for 15 miles to get things warm. Found a parking lot and did some slow figure 8's, there was minimal chatter. I then added approx 1/4 of the additive, buttoned her up and repeated warm up drive followed by more 8's. The chatter was gone! Returned home topped off with Gear Oil and all is good. I can't believe how difficult it is to find gear oil without LSD additive, thats rated for GL5....The only local I could find ( to impatient to order online) was Coastal brand 75W-90 Dino Oil ( not synthetic) with no LS Additive. I think I might upgrade oil ( research pending) when I am ready to service it."