Advance Adapters 50-3001 - Manual (Page 2)

GM TH350 AUTOMATIC
JEEP & SCOUT DANA 18/20 1945-79
ADVANCE ADAPTERS INC. P/N: 50-3001
P.O. Box 247, 4320 Aerotech Center Way Old Part No: 711030-LS
Paso Robles, CA 93447 PAGE 2 OF 3
Telephone: (800) 350-2223 Fax: (805) 238-4201 Page Rev. Date: 07-24-12
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
The GM 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 has the top two holes 8-1/4" apart
or in a Buick bolt pattern that has 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 and you must make sure the proper shaft has been installed into the transmission for use with our transfer case kit.
When overall transmission length is critical, we standardize 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. 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.
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 spud shaft 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.
When assembling the adapter housing to the transmission case, we have provided you with 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.
On most installations, a pan modification will be required for clearance of the front Universal yoke. On early model Jeeps
up to 1965, it may be necessary to change the front transfer case yoke to the smaller design (from a 1966-1971 Buick V6
application). For additional front driveline clearance, we recommend that the engine and transfer case be offset to the
driver's side approximately 1" of centerline. This offset will help the front driveshaft clear the TH350 oil pan.
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 be either 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.
This adapter kit is supplied with a special set screw, Part No. 724319 . It is to be used on Dana 18 transfer cases that have
the dual shift lever type transfer case The set screw will replace the square headed bolt that is used on the inside portion
of the shift handle mounting. By using the set screw configuration, additional clearance can be obtained.
CAUTION: This adapter is not to be used with a GM 700R-4 automatic overdrive transmission. The adapter length
is not long enough to allow for front drive shaft clearance when using the Jeep Dana 18/20 or Dana 300 transfer
cases.