Advance Adapters 477021 User Manual

ADVANCE ADAPTERS INC. P/N: 477021

P.O. Box 247, 4320 Aerotech Center Way New Item: (12/01)
Paso Robles, CA 93447 PAGE 1 OF 14
Telephone: [phone] Fax: [phone] Page Rev. Date: 02-23-11

TOYOTA LOW GEAR 4.7:1 21 SPLINE

For Gear-Driven T ransfer Cases ONLY

The installation of this gear set requires you to almost completely disassemble the transfer case. We have provided
illustrative assembly and disassembly instructions. If your transfer case is in need of a rebuild, now would be the time
to do it.

Here are a couple of points to keep in mind that will make the installation much easier if you've never disassembled a
Toyota transfer case:

1.) Keep all bolts separated into groups as you remove them and label their container.

2.) Keep all small parts in separate containers and label as to location and origin.

3.) Make sure you have plenty of time and a clean, spacious area to perform the installation.

4.) You might want to have a qualified machine shop remove and install the bearings and seals on the new gears,
input shaft and in the case.

5.) The Trail Tamer instructions (in TT001) are to be used as a guide. The official Toyota shop manual is strongly
recommended for your particular application. See Pages 3 & 4 on this instruction sheet to identify your

style transfer case & see what modifications are needed to your transfer case.

TOOLS YOU WILL NEED:

12mm, 14mm and 30mm Metric sockets and ratchet driver
6mm Allen (hex) head wrench
Snap-ring pliers
3/16" (4mm) drift / roll pin punch
Plastic soft blow hammer
Bearing / gear puller with long fingers
Bearing press device
Die grinder

SPECIAL NOTE: The components packaged in this kit have been assembled and machined for specific type of conversions. Modifications to any of the components will
void any possible warranty or return privileges. If you do not fully understand modifications or changes that will be required to complete your conversion, we strongly recommend
that you contact our sales department for more information. This instruction sheet is only to be used for the assembly of Advance Adapter components. We recommend that a
service manual pertaining to your vehicle be obtained for specific torque values, wiring diagrams and other related equipment. These manuals are normally available at automotive
dealerships and parts stores.

ADVANCE ADAPTERS INC. P/N: 477021

P.O. Box 247, 4320 Aerotech Center Way New Item: (12-01)
Paso Robles, CA 93447 PAGE 2 OF 14
Telephone: [phone] Fax: [phone] Page Rev. Date: 02-23-11

TOYOTA LOW GEAR 4.7:1 21 SPLINE

For Gear-Driven T ransfer Cases ONLY

SNAP RING LIST:

This is a list of Toyota snap rings that may be needed for your installation should your stock snap rings
become distorted during disassembly or assembly. These snap rings are stock Toyota parts and can be
obtained at a Toyota parts dealership. Advance Adapters does not carry these components.

36221C
90520-28242 1.50-1.55mm
90520-28248 1.60-1.65mm

36223A
90520-30215 2.10mm
90520-30217 2.20mm

36231F
90520-71221 1.65mm with 71.1mm ID
90520-36250 2.40-2.45mm
90520-36251 2.45-2.50mm
90520-36252 2.50-2.55mm
90520-36253 2.55-2.60mm
90520-36254 2.60-2.65mm
90520-36255 2.65-2.70mm

36212D
90520-72001 1.45mm
90520-72002 1.50mm
90520-72003 1.55mm
90520-72004 1.60mm
90520-72005 1.65mm

SPECIAL NOTE: The components packaged in this kit have been assembled and machined for specific type of conversions. Modifications to any of the components will
void any possible warranty or return privileges. If you do not fully understand modifications or changes that will be required to complete your conversion, we strongly recommend
that you contact our sales department for more information. This instruction sheet is only to be used for the assembly of Advance Adapter components. We recommend that a
service manual pertaining to your vehicle be obtained for specific torque values, wiring diagrams and other related equipment. These manuals are normally available at automotive
dealerships and parts stores.

ADVANCE ADAPTERS INC. P/N: 477021

P.O. Box 247, 4320 Aerotech Center Way New Item: (12-01)
Paso Robles, CA 93447 PAGE 3 OF 14
Telephone: [phone] Fax: [phone] Page Rev. Date: 02-23-11

TOYOTA LOW GEAR 4.7:1 21 SPLINE

For Gear-Driven T ransfer Cases ONLY

BD

1979-80 4SP TRANSFER CASE

A

E

C

Identification points on this transfer case
are the same on the transfer cases below.

A. Extended splines on input shaft.
B. Short Case (.400).
C. 8.125 Front driveline bolts.
D. Transfer case shifter in top of T-case. Short shift rails.
E. Noisy run gears (no front retainer clip).
F. 21 spline input shaft.

Modification Notes:

This transfer case will require modifications to the shift forks. Refer to Assembly
Step A-12 of the in the Toyota Truck Instruction Manual.

The transfer case reduction box may need to be relieved due to core shift. Refer
to Assembly Step A-11 of the in the Toyota Truck Instruction Manual.

F

1981 to (April) 1983 5SP TRANSFER CASE

B. Short Case (.400).
C. 8.125 Front driveline bolts.
D. Transfer case shifter in top of T-case. Short shift rails.
E. Noisy run gears (no front retainer clip).
F. 21 spline input shaft.

Modification Notes:

This transfer case will require modifications to the shift forks. Refer to
Assembly Step A-12 of the in the Toyota Truck Instruction Manual.

The transfer case reduction box may need to be relieved due to core shift.
Refer to Assembly Step A-11 of the in the Toyota Truck Instruction Manual.

1984-88 CARBURETED 5SP TRANSFER CASE

B. Tall Case (.580).
C. 10.125 Front driveline bolts.
D. Transfer case shifter in top of transmission with forward shift rails.
E. Quiet run gears (front retainer clip).
F. 21 spline input shaft.

Modification Notes:

The transfer case reduction box may need to be relieved due to core shift. Refer
to Assembly Step A-11 of the in the Toyota Truck Instruction Manual.

SPECIAL NOTE: The components packaged in this kit have been assembled and machined for specific type of conversions. Modifications to any of the components
will void any possible warranty or return privileges. If you do not fully understand modifications or changes that will be required to complete your conversion, we
strongly recommend that you contact our sales department for more information. This instruction sheet is only to be used for the assembly of Advance Adapter
components. We recommend that a service manual pertaining to your vehicle be obtained for specific torque values, wiring diagrams and other related equipment.
These manuals are normally available at automotive dealerships and parts stores.

ADVANCE ADAPTERS INC. P/N: 477021

P.O. Box 247, 4320 Aerotech Center Way New Item: (12-01)
Paso Robles, CA 93447 PAGE 4 OF 14
Telephone: [phone] Fax: [phone] Page Rev. Date: 02-23-11

TTOYOTA LOW GEAR 4.7:1 21 SPLINE

For Gear-Driven T ransfer Cases ONLY

B

D

CE

Identification points on this transfer case
are the same on the transfer cases below.

1985-88 E.F.I. 5SP TRANSFER CASE

B. Tall Case (.580).
C. 10.125 Front driveline bolts.
D. Transfer case shifter in top of T-case. Short shift rails with low-range

shifter rod proturding out approximately .500.
1985 to August 1988

E. Quiet run gears (front retainer clip).
F. 21 spline input shaft.

Modification Notes:

This transfer case will require modifications to the shift forks. Refer to
Assembly Step A-12 of the in the Toyota Truck Instruction Manual.

F

The transfer case reduction box may need to be relieved due to core shift. Refer
to Assembly Step A-11 of the in the Toyota Truck Instruction Manual.

1989-95 E.F.I. 5SP TRANSFER CASE

B. Tall Case (.580)
C. 10.125 Front driveline bolts.
D. Transfer case shifter in top of transmission with forward shift rails. The

shifter rods are 1/2" shorter than the 1984-88 Carbureted T/C.

E. Quiet run gears (front retainer clip).
F. 21 spline input shaft.

Modification Notes:

The transfer case reduction box may need to be relieved due to core shift.
Refer to Assembly Step A-11 of the in the Toyota Truck Instruction Manual.

Carburated T-cases had shifter in transmission.

1986-87 TURBO E.F.I. 5SP TRANSFER CASE
1988-95 V6 5SP TRANSFER CASE

B. Tall Case (.580)
C. 10.125 Front driveline bolts.
D. Transfer case shifter in top of transmission with forward shift rails.
E. Quite run gears (front retainer clip).
F. 23 spline input shaft.

Modification Notes:

The transfer case reduction box may need to be relieved due to core shift.
Refer to Assembly Step A-11 of the in the Toyota Truck Instruction Manual.

SPECIAL NOTE: The components packaged in this kit have been assembled and machined for specific type of conversions. Modifications to any of the components
will void any possible warranty or return privileges. If you do not fully understand modifications or changes that will be required to complete your conversion, we
strongly recommend that you contact our sales department for more information. This instruction sheet is only to be used for the assembly of Advance Adapter
components. We recommend that a service manual pertaining to your vehicle be obtained for specific torque values, wiring diagrams and other related equipment.
These manuals are normally available at automotive dealerships and parts stores.

ADVANCE ADAPTERS INC. P/N: 477021

P.O. Box 247, 4320 Aerotech Center Way New Item: (12-01)
Paso Robles, CA 93447 PAGE 5 OF 14
Telephone: [phone] Fax: [phone] Page Rev. Date: 02-23-11

TOYOTA LOW GEAR 4.7:1 21 SPLINE

For Gear-Driven T ransfer Cases ONLY

Installation Tips: For those who do not have access to a mill, here is an easy way to clearance your reduction

housing. This procedure requires only some marking fluid and a small angled grinder. This should take you about
1 hour, but remember to take your time and do it slowly. If you do not feel comfortable making these modifications,
we offer P/N 51-5911. This is a heavy duty housing that has been pre-clearanced for these gear sets.

First, test fit your new gear set into your reduction housing. You will notice that the
gears will interfere with the casting in multiple locations. Lightly tap the gear into
the casting. This will score the casting at the interference locations. Now using
marking fluid (paint pen, permanent marker, etc.), take the time to carefully mark
all locations where contact is made.

Now that all your marks have been made, it's time to start slowy removing material
from the casting. Using the grinder equipped with a 50 grit disc, begin to work away
at your marked areas. Remember to take mental note of how much each section
of the casting was contacting the gear. Take special care at this point not to remove
too much material.

After the marked areas have been ground away, go ahead and re-test fit the gears
back into the housing. Make sure to rotate the gear and that it has 360 degree
clearance with all areas of the housing. At this point, it may be necessary to re mark
areas where the gear is still contacting the housing. Repeating this procedure a few
times will insure proper fit and you will avoid the possibility of grinding a hole through
the casting.

With all the grinding done, test fit the gear set one last time making sure that every
thing spins freely and that there are no hang ups or tight spots. In addition to the
case, also remember that the shift rails will require some modifications due to gear
interference. This would be the optimal time to complete this procedure as well.
Make sure that the shift detents are installed to insure proper shift location for
modifications to be made.

SPECIAL NOTE: The components packaged in this kit have been assembled and machined for specific type of conversions. Modifications to any of the components
will void any possible warranty or return privileges. If you do not fully understand modifications or changes that will be required to complete your conversion, we
strongly recommend that you contact our sales department for more information. This instruction sheet is only to be used for the assembly of Advance Adapter
components. We recommend that a service manual pertaining to your vehicle be obtained for specific torque values, wiring diagrams and other related equipment.
These manuals are normally available at automotive dealerships and parts stores.