Landcruiser H42 4 Speed Trans. to Landcruiser
3 speed T-Case
This information covers the
mating of the Toyota Landcruiser H42 4 speed transmission (came factory
in 10/73' - 7/80' Landcruiser's) to the transfer case originally mated to
the Toyota J30 transmission (63' - 9/73').
Frequently Asked Questions
Q: Why are the transfer
cases referred to as "3 speed" or 4 speed"?
A: The name reflects the
transmission they were originally mated to. It does NOT reflect the number
of actual speeds the transfer case has. All transfer cases discussed in
this conversion actually have two speeds, high and low, but as noted, for
identification purposes they will be referred to as either "3 speed" or
Q: What is the advantage
to this swap?
A: The "3 speed" TC has
a lower low range gear ratio, giving you an slightly lower crawl ratio.
The "4 speed" case has a 1.999 low range ratio as opposed to a 2.313 low
range in the "3 speed". Both cases have a 1:1 high range in their stock
Q: Will my driveline's
A: No, the critical TC dimensions
are the same. However, the flange patterns will need to be addressed. You
can either re-use your existing flanges & park brake drums, or source
new/used ones from a reputable dealer.
Q: Can I use a 8/80' and
later Landcruiser H42 4 speed transmission?
A: No, the later 8/80' transmissions
have a 19 spline output shaft and a bolt pattern not compatible with the
one piece transfer cases. They were originally mated to a "split-case"
Q: Can I just swap the
gears out of the "3 speed" TC into my "4 speed" TC case?
A: Yes, however it requires
some special shimming and installation not covered in this article. This
is known to be advantageous as the "4 speed" case is regarded to be a stronger
aluminum case versus the more "brittle" case of the "3 speed".
Q: What if the extra low
range of the "3 speed" TC isn't enough for me?
A: You should investigate
the Advance Adapters Orion Transfer Case. It is available in both 3:1 and
4:1 versions, and requires very few modifications to your drivetrain. Read
more here: http://www.cruiseroutfitters.com/advadapt.html
Q: What parts do I need?
A: Parts List:
1. "3 speed"
- You can source this from many different years of Landcruiser's, but take
note that some "3 speed" transfer cases came in a vacuum shift 4WD variety
that will most likely need to be converted for your installation.
- The input gear of the "3 speed" TC has a 10 spline configuration while
the output shaft of the "4 speed" TC is a 16 spline configuration. Likewise,
the outside diameter tooth count on the 3 & 4 speed TC input gears
are different, so it is crucial to obtain the correct input gear that has
the needed 16 spline inside configuration and the 29 tooth outside configuration.
(Cruiser Outfitters Part#
TCG60030 - $115.50 - OE Japanese)
- The bearing on the back of the TC will need to be changed to a bearing
having the same OD as the original and the ID of the 4 speed transmission's
output shaft. This bearing is available at parts houses (Part# BCA RW114R
or industry standard # 6306-32R-2NSL, the application is a 1974 - 1982
Datsun B210 pickup truck, rear axle bearing). It is also available here.
(Cruiser Outfitters Part#
TCTG06306 - $52.50 - High Quality Japanese)
Case Input Seal & Gasket - At a minimum you will want to put a
new seal in the front of the transfer case and replace the paper gaskets
on the TC including the one between the transmission and the transfer case.
Consider the possibility of doing a complete rebuild depending on the condition
of the case.
(Seal - Cruiser Outfitters
Part# TC42014 - $6.00)
(Gasket Set - Cruiser Outfitters
Part# TCGK6980 - $18.50)
(Complete Rebuild Kit -
Cruiser Outfitters Part# TC6975 - $190)
Case Linkage - The transfer case mechanism on the 3 & 4 speed cases
vary in length and design. You will need to remove the shift fork actuator
housing from your "4 speed" case and install it on the "3 speed" case.
Likewise your existing "4 speed" linkage should be reused. If you don't
have the parts, source used ones from a reputable shop.
Spacer or PTO Gear - The PTO gear or spacer that is currently inside
of the "3 speed" case will not fit over the 4 speed transmissions output
shaft. Thus, you must use your old PTO spacer or PTO gear from your current
"4 speed" transfer case. If you don't have the parts, source used ones
from a reputable shop.
7. Transfer Case
to Transmission Bolts
- Your existing 4 speed bolts should work just fine, if you don't have
the parts, source used ones from a reputable shop.
Q: What else do I need to
A: There are numerous variables
not discussed in this article as every swap is a case by case situation.
However, there are a couple items to discuss that will help make the conversion
*See something missing, wrong,
or incomplete? Please let us know!
The Hi - Low lever on the top
of the "3 speed" TC will need to be rotated to match that of the "4 speed"
TC. This needs to be done before the transfer case is installed in the
vehicle for best access.
If you can't easily remove the
2WD - 4WD actuator housing, it is also possible to remove the entire front
output assembly from the "4 speed" case and install it on the "3 speed
case". This option will also solve your front driveline pattern issue as
you will no longer need to swap the front output flange.
It is possible to modify "3
speed" transfer case linkages to work with the "3 speed" 2wd-4wd shift
actuator, however the amount of time to retrofit and modify they system
and the fact you would then need to swap front output flanges make this
route less appealing.