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ADVANCE ADAPTERS INC. P/N: 50-9600
P.O. Box 247, 4320 Aerotech Center Way Old Part No:
Paso Robles, CA 93447 PAGE 1 OF 2
Telephone: (800) 350-2223 Fax: (805) 238-4201 Page Rev . Date: 09-24-13
6L80/6L90 T O A TLAS ADAPTER
KIT CONSISTS OF:
No. Qty Part No. Description
1 1 51-9600 ADAPTER- ATLAS TO 6L80/6L90 (3.70" LONG)
2 2 724302 FLAT WASHER 7/16" SAE ZINC
3 2 724303 LOCK WASHER 7/16" STD PLTD
4 2 724307 H.H.C.S. 7/16"-14 X 1"
GM’s new Hydra-Matic 6L80/6L90 transmissions are the first of a new family of modular six-speed rear-drive transmissions. The transmissions
feature two overdrive gears and a wide gear ratio spread to improve performance and fuel economy when compared with conventional fourand five-speed automatic transmissions. With two overdrive gears, engine rpm is reduced by approximately 9 percent at 60 mph - a reduction
to about 1,500 rpm. GM estimates the wide ratio spread can help cut 0-60 mph times by as much as 7 percent and enhance fuel economy
by up to 4 percent.
Engineering the all-new Hydra-Matic six-speed transmission with a modular architecture enabled engineers and designers to design a
transmission that is easily adapted to a wide range of vehicles. Equally important, the new six-speed automatic’s modular design means any
of the four primary variants can be manufactured in the same assembly plant.
The modular design of the transmission permits several versions of the transmission to be tailored with minimal changes to the precise
performance requirements of different vehicles. As many as 47 percent of all components are common for all four transmission variants. In
fact, the new transmission design is so flexible that different variants theoretically could run sequentially down the same assembly line. The
new six-speed automatic’s manufacturing plan dovetails completely with GM’s Global Manufacturing System strategy to implement a common
manufacturing process and procedure at every worldwide GM assembly plant.
Technically sophisticated clutch-to-clutch operation reduces complexity and packaging. It also enhances the performance feel of the
transmission, as shifts feel more immediate and precise. It is a simple, less complex design that enables the six-speed transmission to be
packaged in a size not much larger than a four-speed automatic.
Notes: Notes:
Notes: GM’s new Hydra-Matic 6L80 & 6L90 transmissions are the first of a new family of modular six-speed rear-drive
Notes: Notes:
transmissions. The transmissions feature two overdrive gears and a wide, 6.04:1 gear ratio spread to improve
performance and fuel economy when compared with conventional four- and five-speed automatic transmissions. With
two overdrive gears, engine rpm is reduced by approximately 9 percent at 60 mph - a reduction to about 1,500 rpm. Lower
engine rpm can bolster fuel economy because less fuel is used. A lower-rpm cruising speed also enhances smoothness
and reduces noise heard in the vehicle’s cabin.
The gear ratio’s are 1st - 4.03:1 / 2nd - 2.36:1 / 3rd - 1.53:1 / 4th - 1.15:1 / 5th .085:1 / 6th .67:1.
The 6L80 uses a 32 spline output shaft in the 4WD and 2WD model transmissions. Transmission length 23.2"
The 6L90 uses a 29 spline output shaft in the 4WD. Transmission length 24.6"
Please verify your spline information before starting any project.
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.
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ADVANCE ADAPTERS INC. P/N: 50-9600
P.O. Box 247, 4320 Aerotech Center Way Old Part No:
Paso Robles, CA 93447 PAGE 2 OF 2
Telephone: (800) 350-2223 Fax: (805) 238-4201 Page Rev . Date: 07-24-14
6L80/6L90 T O A TLAS ADAPTER
6.75" stickout on a 2WD transmission. the shaft will need to be
cut or shortend to 3.80 cut off
This casting is designed for the stock 4WD output shaft. The
6L80 shafts are 32spline and the 6L90 is a 29 spline.
2008 2WD 6L80 output shaft has, approximately 7" of shaft
stick out and 6" of splines. This shaft could be cut and the
casting used at the 3.7" length.
Stock 4WD output shaft with 1.62" of spline. This spline
should be recessed from the casting face .300" once the
casting is installed.
Shaft on the right is a fixed yoke 2WD trans. This shaft must
be modified to work with an Atlas.
On 2WD transmissions the holes located at 12 and 6
o’clock need to be plugged with factory soft plugs.
The output shaft needs to have a seal installed.
Installation:
have included two sets of transfer case holes for the Atlas to offer multiple rotation options for both the right
and left drop case configurations. The 7/16 bolts included are for the factory GM rubber support mount. Your
stock crossmember will need to be modified to connect to the GM rubber support
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.
The new casting is designed to use the factory bolts to fasten the adapter to the transmission. We