Here is a summary for those of you considering an AOD. I was initially set on a early non-electric AOD, but quickly decided against it after learning about the benefits of the 4R70W.
4R70W Swap Introduction:
-Updated 3/3/2011
The following is a summary of the installation of a 4R70W into my 1967 Cougar. I was initially set on an early non-electric AOD. After doing some research, I came to the conclusion that early AODs have many weak points. Rebuilt “bulletproof” AODs are available with upgraded parts, but they are very expensive. I was initially looking at a $1,800 rebuilt early AOD. The transmission I was interested in had a wide ratio gear set from a 4R70W. This single upgrade was $300.
I decided to research other, more affordable options. I came across a post discussing the 4R70W transmission. The 4R70W is a computer controlled wide-ratio AOD found in many late model Fords. The wide ratio gearing provides a lower first and second gear to aid in acceleration. Even in its stock form, the 4R70W is a very durable transmission. Unlike the early AOD, the 4R70W already has the good parts.
I was not completely sold on the 4R70W due to the expensive electronics, limited information about the swap, and nonexistent conversion parts. I decided to pursue the 4R70W further after talking to Joe Persad, a member of the All Ford Mustang forum. Joe had already completed the 4R70W swap, and offered to reproduce the conversion parts. I was completely sold after finding many low mile local transmissions for next to nothing. I ended up purchasing a low mile 2002 3.8L 4R70W with torque converter for $200. The transmission even had a 1-year warranty. Keep in mind I was quoted $300 to upgrade a early AOD to wide ratio gearing, and here I purchased an entire wide-ratio transmission/torque converter for $200.
Additional information:
http://www.becontrols.com/tech/tech.htm
http://www.becontrols.com/tech/ch4usedtrans.htm
http://tccoa.com/articles/tranny/index.html
Transmission:
-The conversion requires a 4R70W from a late model 3.8L, 4.2L, 5.0L vehicle.
-1998+ 4R70Ws are recommended due to several mechanical improvements.
-Compatible 4R70Ws are identified by a 2 bolt starter flange. This version will have the proper bolt pattern for small block 289, 302, and 351. See the links above for more information.
-The 3.8L version has one less clutch plate than the 4.2L/5.0L unit. Therefore, the 4.2L/5.0L unit is preferred for high performance engines. However, the 3.8L V6 version is generally less expensive, and easier to find with low miles. Also, the 3.8L version can be upgraded with an extra clutch plate if desired. My research suggests that unlike the early AODs, the V6 4R70W need not be avoided.
-2003 and newer models do not have teeth on the output shaft. Therefore, they cannot support a mechanical speedometer.
Yoke/Driveshaft:
The 4R70W extension housing only accepts a 4R70W slip yoke due to the larger output bushing. You can swap extension housings in order to use a smaller C4, early AOD, or T5 slip yoke. I decided to keep the extension housing and use a 4R70W yoke from a 2002 Crown Victoria P71. The driveshaft had to be shortened to 52” due to the extra length of the AOD.
Flywheel, Block Plate, Starter:
I had to install a larger 164 tooth 28 oz flywheel. I also needed a new block/ inspection plate. These parts were necessary because my previous trans was a small bell housing C4. You may already have the proper parts depending on your application. My aftermarket mini-starter easily bolted to the AOD without any problems.
Cooling lines:
One of the stock cooling lines had to be modified (shortened and bent) to fit the 4R70W. The other line fit fine without modifications. It is highly recommended that you install an aftermarket plate type transmission cooler. I installed a B&M super cooler with braided steel lines.
Torque Converter:
I used the stock 3.8L torque converter. According to my Ford Shop CD, it has a stall speed of 2,207-2,590. Now, I am not sure how Ford determined this number. It is likely calculated as connected to a 3.8L engine.
Transmission Cross Member:
Due to the extra length of the AOD, the C4 cross member cannot be used. I purchased my cross member from Joe Persad, "silver69" from the All Ford Mustang Forum, joepersad@aol.com
Side note, the C4 rubber transmission mount worked fine with the aftermarket cross member.
Electronics:
http://www.becontrols.com
I purchased a Baumann TCS to control the transmission. The TCS allows you to modify the trans shift pattern (and a whole lot more) with a laptop. Pretty cool! The wiring is straight forward with the Baumann full harness. Details are available on the Baumann website. You will also need to install a Throttle Position Sensor (TPS). This takes the place of the TV cable found on early AODs. There are several TPS options. I went with a Holley TPS from Summit Racing. This is the easiest route and bolts right up to most Holley carburetors.
Shifter:
The 4R70W originally had a cable shifter linkage. I decided to use a conventional shifter rod at the recommendation of Joe Persad. Joe was in the process of making the shifter components, but the parts were not quite ready when I required them. As a result, I fabricated my own range sensor bracket and shifter rod based on his photos. I used components from a Lokar Column Shift Linkage. Several modifications to the range sensor are required to use a shifter rod. See my Picasa gallery for more information. The shifter rod and range sensor bracket are now available from Joe Persad, "silver69" from the All Ford Mustang Forum, joepersad@aol.com
Exhaust:
The 4R70W is much larger than the C4. As a result, the stock exhaust pipes did not clear the 4R70W. Modifying the H-pipe section would likely provide enough room. The clearance problem gave me an excuse to upgrade to a complete Magnaflow stainless exhaust (and coated headers too). A full exhaust replacement was not necessary by any means, and will not be included in the cost of the conversion. I would recommend having a muffler shop tweak your existing setup.
Speedometer:
I changed the plastic speedometer gear as the speedometer was not accurate. This was due to different number of teeth on the 4R70W output shaft (in comparison to the C4). Again, 2002 is the last year which supports a mechanically driven speedometer.
Other Transmission Modifications:
-There are two machining locators on the top of the trans case toward the rear. They can cause possible clearance issues and should be cut off.
-The filler tube will require minor bending to fit.
-New longer bolts are required to bolt the trans to the motor.
Optional:
-I performed the “J-Mod” which is a shift kit created by Jerry, one of the engineers who designed the 4R70W. The J-Mod includes removing two springs and enlarging several holes in the separator plate. I ended up reinstalling the lower accumulator spring as the 1-2 shift was far too aggressive. I do not recommend the J-Mod unless you like very aggressive shifts.
-I installed a deep, extra capacity TCI pan.
Cost breakdown:
Baumann Controller and Full Harness $550.00
4R70W $200.00
P71 Yoke $40.00
Driveshaft Shortening $90.00
Hawks Racing flywheel $59.99
B&M aluminum plate cooler $58.25
Holley TPS $99.95
Block plates $28.50
Cross member $99.00
Misc Shifter Linkage Parts $60
Estimated cost to modify stock exhaust $100.00
Total $1,385.69
Again, I am not including the unnecessary items such as the braided cooler lines, TCI pan, or Magnaflow exhaust.
You could save a few bucks by using a trans cooler from a late model F-series truck, fabricating a cross member, and so on...
There is a good chance the entire swap could be done for around $1,000 if you spend your pennies wisely.
Driving Impressions:
As of today (3/3/2011), I have put about 600miles on the transmission. The car gets about 15mpg (3.55 rear), but I think it can achieve 18mpg with a few carburetor adjustments, and a lighter right foot. The car is definitely very fun to drive. I think the wide ratio gearing really helps the little 289 feel powerful. I am very happy with my 4R70W choice!
I hope this information is helpful. Photos are available in my gallery.
Good Luck,
4R70W Swap Introduction:
-Updated 3/3/2011
The following is a summary of the installation of a 4R70W into my 1967 Cougar. I was initially set on an early non-electric AOD. After doing some research, I came to the conclusion that early AODs have many weak points. Rebuilt “bulletproof” AODs are available with upgraded parts, but they are very expensive. I was initially looking at a $1,800 rebuilt early AOD. The transmission I was interested in had a wide ratio gear set from a 4R70W. This single upgrade was $300.
I decided to research other, more affordable options. I came across a post discussing the 4R70W transmission. The 4R70W is a computer controlled wide-ratio AOD found in many late model Fords. The wide ratio gearing provides a lower first and second gear to aid in acceleration. Even in its stock form, the 4R70W is a very durable transmission. Unlike the early AOD, the 4R70W already has the good parts.
I was not completely sold on the 4R70W due to the expensive electronics, limited information about the swap, and nonexistent conversion parts. I decided to pursue the 4R70W further after talking to Joe Persad, a member of the All Ford Mustang forum. Joe had already completed the 4R70W swap, and offered to reproduce the conversion parts. I was completely sold after finding many low mile local transmissions for next to nothing. I ended up purchasing a low mile 2002 3.8L 4R70W with torque converter for $200. The transmission even had a 1-year warranty. Keep in mind I was quoted $300 to upgrade a early AOD to wide ratio gearing, and here I purchased an entire wide-ratio transmission/torque converter for $200.
Additional information:
http://www.becontrols.com/tech/tech.htm
http://www.becontrols.com/tech/ch4usedtrans.htm
http://tccoa.com/articles/tranny/index.html
Transmission:
-The conversion requires a 4R70W from a late model 3.8L, 4.2L, 5.0L vehicle.
-1998+ 4R70Ws are recommended due to several mechanical improvements.
-Compatible 4R70Ws are identified by a 2 bolt starter flange. This version will have the proper bolt pattern for small block 289, 302, and 351. See the links above for more information.
-The 3.8L version has one less clutch plate than the 4.2L/5.0L unit. Therefore, the 4.2L/5.0L unit is preferred for high performance engines. However, the 3.8L V6 version is generally less expensive, and easier to find with low miles. Also, the 3.8L version can be upgraded with an extra clutch plate if desired. My research suggests that unlike the early AODs, the V6 4R70W need not be avoided.
-2003 and newer models do not have teeth on the output shaft. Therefore, they cannot support a mechanical speedometer.
Yoke/Driveshaft:
The 4R70W extension housing only accepts a 4R70W slip yoke due to the larger output bushing. You can swap extension housings in order to use a smaller C4, early AOD, or T5 slip yoke. I decided to keep the extension housing and use a 4R70W yoke from a 2002 Crown Victoria P71. The driveshaft had to be shortened to 52” due to the extra length of the AOD.
Flywheel, Block Plate, Starter:
I had to install a larger 164 tooth 28 oz flywheel. I also needed a new block/ inspection plate. These parts were necessary because my previous trans was a small bell housing C4. You may already have the proper parts depending on your application. My aftermarket mini-starter easily bolted to the AOD without any problems.
Cooling lines:
One of the stock cooling lines had to be modified (shortened and bent) to fit the 4R70W. The other line fit fine without modifications. It is highly recommended that you install an aftermarket plate type transmission cooler. I installed a B&M super cooler with braided steel lines.
Torque Converter:
I used the stock 3.8L torque converter. According to my Ford Shop CD, it has a stall speed of 2,207-2,590. Now, I am not sure how Ford determined this number. It is likely calculated as connected to a 3.8L engine.
Transmission Cross Member:
Due to the extra length of the AOD, the C4 cross member cannot be used. I purchased my cross member from Joe Persad, "silver69" from the All Ford Mustang Forum, joepersad@aol.com
Side note, the C4 rubber transmission mount worked fine with the aftermarket cross member.
Electronics:
http://www.becontrols.com
I purchased a Baumann TCS to control the transmission. The TCS allows you to modify the trans shift pattern (and a whole lot more) with a laptop. Pretty cool! The wiring is straight forward with the Baumann full harness. Details are available on the Baumann website. You will also need to install a Throttle Position Sensor (TPS). This takes the place of the TV cable found on early AODs. There are several TPS options. I went with a Holley TPS from Summit Racing. This is the easiest route and bolts right up to most Holley carburetors.
Shifter:
The 4R70W originally had a cable shifter linkage. I decided to use a conventional shifter rod at the recommendation of Joe Persad. Joe was in the process of making the shifter components, but the parts were not quite ready when I required them. As a result, I fabricated my own range sensor bracket and shifter rod based on his photos. I used components from a Lokar Column Shift Linkage. Several modifications to the range sensor are required to use a shifter rod. See my Picasa gallery for more information. The shifter rod and range sensor bracket are now available from Joe Persad, "silver69" from the All Ford Mustang Forum, joepersad@aol.com
Exhaust:
The 4R70W is much larger than the C4. As a result, the stock exhaust pipes did not clear the 4R70W. Modifying the H-pipe section would likely provide enough room. The clearance problem gave me an excuse to upgrade to a complete Magnaflow stainless exhaust (and coated headers too). A full exhaust replacement was not necessary by any means, and will not be included in the cost of the conversion. I would recommend having a muffler shop tweak your existing setup.
Speedometer:
I changed the plastic speedometer gear as the speedometer was not accurate. This was due to different number of teeth on the 4R70W output shaft (in comparison to the C4). Again, 2002 is the last year which supports a mechanically driven speedometer.
Other Transmission Modifications:
-There are two machining locators on the top of the trans case toward the rear. They can cause possible clearance issues and should be cut off.
-The filler tube will require minor bending to fit.
-New longer bolts are required to bolt the trans to the motor.
Optional:
-I performed the “J-Mod” which is a shift kit created by Jerry, one of the engineers who designed the 4R70W. The J-Mod includes removing two springs and enlarging several holes in the separator plate. I ended up reinstalling the lower accumulator spring as the 1-2 shift was far too aggressive. I do not recommend the J-Mod unless you like very aggressive shifts.
-I installed a deep, extra capacity TCI pan.
Cost breakdown:
Baumann Controller and Full Harness $550.00
4R70W $200.00
P71 Yoke $40.00
Driveshaft Shortening $90.00
Hawks Racing flywheel $59.99
B&M aluminum plate cooler $58.25
Holley TPS $99.95
Block plates $28.50
Cross member $99.00
Misc Shifter Linkage Parts $60
Estimated cost to modify stock exhaust $100.00
Total $1,385.69
Again, I am not including the unnecessary items such as the braided cooler lines, TCI pan, or Magnaflow exhaust.
You could save a few bucks by using a trans cooler from a late model F-series truck, fabricating a cross member, and so on...
There is a good chance the entire swap could be done for around $1,000 if you spend your pennies wisely.
Driving Impressions:
As of today (3/3/2011), I have put about 600miles on the transmission. The car gets about 15mpg (3.55 rear), but I think it can achieve 18mpg with a few carburetor adjustments, and a lighter right foot. The car is definitely very fun to drive. I think the wide ratio gearing really helps the little 289 feel powerful. I am very happy with my 4R70W choice!
I hope this information is helpful. Photos are available in my gallery.
Good Luck,