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Discussion Starter #1
I've seen whole bunches of threads about how one LSD is better or how great it is to have one, but I'm wondering how hard it is to install one. I am already aware of the need to pull the tranny, but looking at the diagrams in the service manual it looks like you need to unbolt the 2 parts of the housing for the tranny. It doesn't look like you actually need to remove any gears or anything, the bolts appear to face the right direction to just unbolt the Open Diff and replace with the LSD....

But I'm sure that it's not really THAT simple... Can anyone enlighten me further?
 

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The new differential will be slightly different is overall height, so it will need to be measured for clearance or a lack of to the housing, and then new thrust shims might be required to bring the assembly stack up into spec. Look in the manual for the spec and location for the measurement. The shims will need to be ordered after you get the measurement, so it will slow the process down.

The old ring gear must be transferred to the new diff, and the bolts that hold the ring gear to the diff should not be reused.
 

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Discussion Starter #3
These clearance/shimming issues should be known for various diffs vs a stock c64. Anyone who's done it care to share? The info about not reusing the bolts for the ring gear is interesting.... I don't have the toyota engine/tranny manual yet, but obviously would get it before proceeding. Are any special tools required for this job?

I'm also wondering about the technique for getting the tranny out. I seem to recall hearing that you need to shift the motor to get it out. I guess that must mean one needs the motor lift hooks and bolts a chain and a crane... but I worry about shifting the motor very far. Obviously it probably has some wiggle room but at some point one must be endangering the exhaust or other connections.

Also with undoing the bolts obviously the tranny needs to be supported...

How heavy is the tranny? if one supports it with a tranny jack, that will add 8-10 inches, which could make it hard to jack up the car far enough to get it out...
 

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This shims needed could vary from dif to dif, and from tranny to tranny. It is the manufacturing tolerances that are concerned. You can't just say that this type of diff will need xxx thickness of shim. You have to assemble the casing dry with the new dif and all bearings and the original thrust washer. Do the measurement, calculate the needed thrust washer... and then order it from the dealer. It is in the manual...

ASSEMBLE DIFFERENTIAL CASE
(a) Install the correct thrust washers and side gears.
Refer to the table below, select thrust washers which will
ensure that the backlash is within the specification. Tr> "o
select washers of the same size for both sides.
Standard backlash:
0.05 - 0.20 mm (0.0020 - 0.0079 in.)
Thickness mm (in.)
0.95 (0.0374)
1.00(0.0394)
1.05(0.0413)
Thickness mm (in.)
1.10(0.0433)
1.15(0.0453)
1.20(0.0472)
(b) Install the thrust washers and side gears in the differential
case.
(c) Install the pinion shaft.
Q00807
(d) Using a dial indicator, check the side gear backlash.
Measure the side gear backlash while holding one pinion
toward the differential case.
Standard backlash:
0.05 - 0.20 mm (0.0020 - 0.0079 in.)
If the backlash is not within the specification, install a thrust
washer of different thickness.
(e) Using a pin punch and hammer, drive in the straight pin
through the differential case and hole in the pinion shaft.
(f) Using a chisel and hammer, caulk the pin holes around
the circumference of the differential case.

The preload on the differential carrier taper roller bearings is controlled by shims between the bearing
outer race and the clutch housing, and is determined by installing the final drive assembly in an otherwise
empty casing, and measuring the steady rotation torque.
When setting the differential bearing preload (see page 41-28 in Toyota manual D120T0327J) note that a
different procedure must be used due to the construction of the LSD. Instead of fitting only the differential
assembly into the transaxle/transmission case, and then measuring the turning torque directly at the differential,
LSD versions require that the differential and output shaft be assembled into the casings, and
the turning torque measured by using a torque wrench (27mm socket) on the end of the output shaft.
- Bearing preload (at starting):
New bearings: 0.17 - 0.35 Nm (1.7 - 3.6 kgf.cm)
Used bearings: 0.11 - 0.22 Nm (1.1 - 2.2 kgf.cm)
If the preload is not within the specification, remove the transmission
case side outer race of the tapered roller bearing with
SST (See page MX-46). Select an appropriate shim.
HINT:
The preload will change by about 0.3 - 0.4 N-m (3-4 kgf-cm,
2.6 - 3.5 in.-lbf) corresponding to a change of 0.05 mm (0.0020
in.) in shim thickness.
Mark Thickness mm (in.)
AA 2.10(0.0827)
BB 2.15(0.0846)
CC 2.20 (0.0866)
DO 2.25 (0.0886)
EE 2.30 (0.0906)
FF 2.35 (0.0925)
GG 2.40 (0.0945)
HH 2.45 (0.0965)
JJ 2.50 (0.0984)
KK 2.55(0.1004)
LL 2.60(0.1024)
MM 2.65(0.1043)
IMN 2.70 (0.1063)
PP 2.75(0.1083)
QQ 2.80(0.1102)
RR 2.85(0.1122)
SS 2.90(0.1142)
TT 2.95 (0.1161)
UU 3.00(0.1181)
 

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I did it myself but would gladly pay if had to be done again. It's a pain... You do need to disassemble the tranny, 5th, 6th gearsets need to be pulled very carefully (special tools and patience needed), otherwise they break, the case needs to be cleaned and dry, then you mess with the clearances... to get the tranny off, you need to unbolt 3 motor mounts so the engine can tilt down, the axles also like getting stuck, everything is really sharp... If you use the car on the track at all I would say the LSD is a must have, if not, don't bother. Good luck!
 

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I also did a LSD install a few months ago. I read somewhere that book time is 9 hours for RR of the Trans, and 9 hours for RR of the LSD. That's 18 hours for a professional, so I estimated that it'd be 40 hours for me as a first timer amateur. Over all it took 2.5 weeks (only nights), and most of that was waiting for parts from the toyota dealer. The shims are never in stock, and I broke a few bolts. You'll need a few different pullers, a shop press, an engine crane, and an impact gun. The rest is basic tools.
You should also remove the clam when doing this...

And after all that work, I'm not sure it's worth it.
 

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Discussion Starter #8
Thanks for all the responses! It does sound like a lot of work. Also I see about $400 in new tool costs there too. So it's a question of $400, a lot of time and a fair bit of risk vs $3500 to have it installed (estimate from dealer, need to shop a bit to see if others can do better, but not sure who to trust with it around here either).

I'm sure it's worth it if the money is available, but is it worth waiting until the money is available. Been running the open diff for a while now but life keeps throwing expenses at me (new house, furniture, etc). Getting tired of waiting, so I'm looking for ways to lower the financial barrier.
 
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