Installing an AODE transmission into a 1969 Bronco
The following describes the steps required to install a late model AODE type transmission into an early model Ford Bronco. This transmission replaced the original 3 speed manual transmission.
The Bronco is a 1969 model with a 302 ci V8 engine. The vehicle is stock except for the recently installed 3.5 inch suspension lift. The transmission being installed is an AODE/W transmission. This transmission has 4 speeds, the fourth being overdrive, and the torque converter has a lock-up clutch. The "E" in the name indicates that the transmission's shifting is electrically controlled. The "/W" indicates that the transmission has a wide ratio set of gears. The wide ratio gears compared to the standard gears are listed below.
|
Standard |
Wide |
|
|
First Gear |
2.40-1 |
2.84-1 |
|
Second Gear |
1.47-1 |
1.55-1 |
|
Third Gear |
1-1 |
1-1 |
|
Fourth Gear |
0.67-1 |
0.7-1 |
The AODE/W is the same as the "4R70W". These are all electrically controlled and contain the wide ratio gear set. The transmission started production around 1993 as the AOD was being phased out; these had the standard ratio gears. By 1996 all the transmissions had the wide ratio gears. There is not a big demand for these late model transmissions yet. I was able to get mine for $500.00 with virtually no mileage on it.
Electrically controlled transmissions have many advantages. One is that the controller can easily modify the shift points and performance characteristics. To control this transmission I choose the TCS controller from Baumann Engineering. This controller allows the shift points to be reprogrammed using the graphical software. Contact Baumann for more information.
The AODE transmission is about one inch longer in length than the predecessor AOD is. This added length comes from the lockup clutch in the torque converter. Internally the transmission is the same except for some minor improvements made through its evolution. The shifting and pressure control is now done using solenoid valves. The governor and several items in the valve body have been removed compared to the AOD.
All small block Ford engines since 1966 have the same bell housing bolt pattern. This opens up a large selection of transmissions.
The transmission for this project is from a 1996 Ford F150. The tail housing for the transmission is for a 2WD truck, but this did not matter. The tail housing is discarded and replaced with the adapter from Advanced Adapters.
Using a book from Haynes, dismantle the transmission and inspect the clutch disks and plates. The tail shaft must be removed and replaced with the tail shaft supplied by Advanced Adapters. Note that the tail shaft supplied in the kit is made for an AOD. Since the AODE does not have a governor the supply line must be plugged. This supply line is inside the output shaft and comes out between the slip rings on the shaft. It seems that Ford must have used the original AOD shafts in early AODEs. They created a pin and ring to plug this hole. The part numbers are:
391-231S The Pin
F2VY7B176-A Sleeve to keep the pin in the shaft
RC-388104-S2 Governor snap ring to hold the sleeve on.
Pictures 4,5, 6, 10, 11 show the pin and output shaft. Picture 4 shows how the pin is inserted into the shaft. Image 6 is the AODE output-shaft that is much longer than the replacement shaft shown in 5. The ring to keep the pin in the shaft is shown on 10 and 11.
While the transmission is apart upgrade the intermediate clutch to a "Mechanical Diode" from Raybestos. The original roller style intermediate clutch is a "weak" link in this transmission. The upgrade to a mechanical diode is simple and does not cost much. To improve the shift firmness and torque handling capability of the tranny install a shift recalibration kit from Baumann Engineering. This kit has 5 levels of performance in one kit. After completing the valve body recalibration the transmission is closed up.
To mate the torque converter to the engine, a flex plate with an 11.4-inch bolt circle is needed. B&M has several to choose from. For a 1969 Bronco with a 302 V8 use the flexplate #50237. The starter must be changed to a starter for an automatic transmission. The flex plate is pictured in 14 and 15.
To support the rear of the transmission, Adaptec suggests notching the original support bar to clear the bottom of the adapter. This will not work with an AODE transmission because of the added length. It appears that the modifications would be to extreme. Instead I will manufacture my own support brace. See the enclosed pictures 19, 20, 21, 22,and 23. The brace is made using 2-inch angle iron, 1-inch square tubing and 3 inch steel bar stock. The cuts are relatively easy to make, and everything welds together nicely. Rubber mounts can be fabricated from left over urethane bushings from a suspension system. I picked these up free from 4 Wheel Parts Wholesale. The new bushings are 2 inches long. Cut them down to 1.5 inches and cut the steel sleeve inside shorter to allow for compression. This new brace bolts up to the original frame mounts.
The transfer case attaches to the adapter without any problem. The transfer case is now approximately 3 inches farther towards the rear of the vehicle. The front and rear drive shafts need to be modified. The driveshaft length measures as follows:
Front drive shaft: 27 inches
Rear drive shaft: 32.5 inches
My vehicle has a 3.5-inch Wild Horses suspension lift. Make your own measurements. One concern after installation of the front driveshaft is the clearance between the shaft and the transmission oil pan. The clearance is very small. To increase clearance I "modified" the oil pan with a hammer. The point closest to the drive shaft can be flattened; clearance inside the transmission is not a problem. The hole in the floor for the transfer case needs to be extended back 3 inches (picture 28).
The transmission cooling lines are on the passenger side. With exhaust headers, a sharp bend has to be made over the top of the collector. I used high-pressure rubber hose and 90-degree brass fittings to join the transmission to steel tubing running along the frame. To further shield the rubber hose from heat slip a piece of firesleeve over the hose.
At this time there is not a shifter designed to work with the AODE transmission. I decided to take a B&M Quick Silver shifter and modify it for my transmission. The shifter arm for the transmission is fabricated by using the part included in the kit for GM applications. The hole for the shaft needs to be enlarged to fit over the Ford shaft. The original cable shifter for this transmission entered from the front. This mounting plate can not be used, but a simple mount can be fabricated by welding two pieces of angle iron perpendicular to each other (picture 24). The shifter is installed according to the instructions using the fabricated arm and cable mounting bracket (picture 27).
Now that the mechanical parts are installed the wiring harness can be created. The end of the wiring harness that connects to the transmission should be supplied by the salvage yard. Use this piece of the harness to create the custom harness for the controller. For the TCS controller from Baumann, their computer comes with it's own cable. The TCS cable is spliced together with the Ford wiring harness. Another set of wires is spliced in from a throttle position sensor. For the TCS controller to work it needs feedback from a throttle position sensor (TPS). A carburetor typically does not have a TPS so a custom bracket must be fabricated. I used a 2 x 2 inch angle piece of aluminum to hold a TPS in front of the linkage. The TPS and linkage are linked together with a spring so that over travel or binding will not interfere with the linkage or break the sensor. With a recommendation from Baumann I used a TPS made for an 86 Buick. This TPS is easy to mount and cheaper than most. Picture 32 shows how the TPS is mounted beside the carburetor. The connection is made using a spring shown in picture 34.
Borg Warner EC3001 Throttle Position Sensor
Finished! Fill up the tranny and test it out. I am enjoying the ease of driving on the trails with an automatic transmission. The second advantage is the electronic control. I can adjust all shift points and the lockup clutch behavior through an easy to use windows program. A nice software feature found in the vehicle setup screen is where the gear ratio for the differential and the tire diameter is entered. The transmission has a sensor to measure the output RPMs of the output shaft. The computer can use the output RPM, gear ratio and tire diameter to calculate the speed of the vehicle. If the tire diameter or gear ratio is changed the software can be adjusted for this. With a non-electronic transmission the valve body must be removed to adjust the shift points. With the TCS controller two different shift profiles are stored in the computer. A toggle switch selects which profile is used. This can be used for "On road / Off road" driving or maybe "4 Wheel High / 4 Wheel Low". With a computer controlling this tranny, your imagination is the limit.
Image Index
Reference
Ford Automatic Transmission Overhaul Manual, Haynes Publishing Group: http://www.haynes.com/
Use this link to purchase the book from Barnes and Noble:
HAYNES FORD AUTOMATIC TRANSMISSION OVERHAUL MANUAL
Baumann Engineering: http://www.baumannengineering.com/
