Advance Adapters 50-5700 - Manual (Page 2)

GM TH350 AUTOMATIC TRANS TO
TOYOTA TRUCK 1979-95 (21-SPLINES)
ADVANCE ADAPTERS INC. P/N: 50-5700
P.O. Box 247, 4320 Aerotech Center Way Old Part No: 711057
Paso Robles, CA 93447 PAGE 2 OF 3
Telephone: (800) 350-2223 Fax: (805) 238-4201 Page Rev. Date: 01-16-12
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.
GM TH350 3 SPEED AUTOMATIC
This adapter will work on all Toyota 4WD trucks, 1979 through November 1995. The General Motors TH350 has a case
length of 21-1/2", 13 bolts for holding the oil pan in position and is available in two different engine to transmission bolt
patterns. The case is available with a Chevy bolt pattern that have the top two holes 8-1/4" apart or in a Buick bolt pattern
that have the top two holes 7" apart. The rear side of the transmission case should have a square bolt pattern that uses
4 bolts. There are several various lengths of output shafts that the transmissions have been furnished with. You must make
sure the proper shaft has been installed into the transmission for use with the Advance Adapter transfer case kit. When
overall transmission length is critical, we standardize our adapters on the GM 4WD output shafts that were used in vehicles
1973-79. If the transmission you purchased has the correct output shaft, you can return the new output shaft for credit.
Some kits will simply require the existing 2WD shaft to be shortened for use with the new coupler. Make sure that you
measure the cutoff location correctly in order to avoid any additional expenses. All TH350 output shafts will have 27 splines.
The speedometer gear is normally located in the tailhousing, but when adapting it to the transfer case, the location will
change to the back side of the transfer case. The rear transmission support is located in the main case just forward of
the tailhousing connection. This can be used for supporting the crossmember on some installations, but most of our kits
provide support on the new adapter housing.
Make sure the bearing retainer clip found on the front side of some transfer cases is removed prior to assembly of the new
adapter. This clip was used to retain lower bearing in Toyota transfer case.
The coupler in this kit is made for a 21 spline male shaft that protrudes from the front of your transfer case. When replacing
transmissions that were equipped with turbocharged engines, you will need to use a 23 spline coupler in place of the 21
spline coupler furnished with this kit.
When installing the new transfer case adapter, make sure that the coupler and the output shaft do not bottom out. We have
found on occasion that a transmission output shaft may be slightly longer than we have allowed for; and when coupling
into our new spud shaft, we find a small amount of interference. The adapter housing and coupler must be assembled to
the back of the transmission without interference.
DO NOT FORCE THE NEW TAILHOUSING ONTO THE
TRANSMISSION. If assistance is needed, please feel free to call the number listed above. Some early model transfer case
input shafts ('79-80) may need to have a spline relief ground in the Toyota shaft to permit the proper spline engagement.
When assembling the adapter housing to the transmission case, we have provided a new square-type "O" ring seal to prevent
fluid leakage. This seal is a stock GM item that is used on all TH350 installations.
If you have selected a transmission that has the old style modulator, then we recommend the use of the Advance Adapters
adjustable modulator, Part No. 716010. This will also allow for additional driveshaft clearance.
All installations will require the use of a transmission cooler. The cooler can either be installed in the radiator or a remote
location is acceptable. The transmission shift control can either be a Hurst floor mounted type shifter or sometimes the
existing column shift can be modified on certain applications.
The linkage on the Toyota transfer cases will vary. Some have the control lever on the tailhousing of the transmission,
while others have it on the transfer case. This adapter can be used with either style. If the opening is not used on the top
of the new housing, you will need to cover the square opening with the cover provided.
If you have a 1989 - 95 electronic fuel injected 4 cylinder. The transfer case shifter linkage was relocated on the 5 speed