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Installing a 4R70W overdrive transmission in an older or classic Ford.

190K views 114 replies 19 participants last post by  CalebTheCarNinja 
#1 · (Edited by Moderator)
have learned a few things about installing a 4R70W overdrive transmission in an older Ford. I was driving to a drag strip with my 64 Fairlane and realized after a couple hours that I needed overdrive. I had street gears but installed some shorter tires for the strip and ran almost 3,500 RPM the whole way. I also wanted to do a Power Tour and I was feeling a need for overdrive. The combination of poor mileage, noise, and engine wear just made it time to do something. I had a PA performance C4 in the car that worked great and I liked how hard it shifted. I wondered about my options and hoped I could get something to work as well as the C4 but have overdrive.

It seemed like the AOD was the obvious choice and I found a good deal on one with a higher stall converter and bought it. Well is it the correct choice? I like many thought you can’t run one of those computer controlled 4R70W or AODE transmissions anywhere close in price to an AOD. Can you? I will keep this to small block Ford engines since that is what I have. Here are some things I found out. This info comes from many sources and is accurate as far as I know but do your homework. The AOD was introduced about 1980 and will need a perfectly adjusted linkage that will have to be purchased and may be good for about 350 HP with stock internals and a shift kit.

An AOD uses a weaker two-piece input shaft for overdrive that is more mechanical and they are just not as strong. If you can find a good one they are also more expensive just due to the demand since they are now becoming more rare and more prone to failure. The 4R70W showed up around 1993 and is an AODE with a wide ratio gear set and some improvements. Newer is better in this case and Ford fixed most of the AOD’s problems with these new transmissions. 1998 on up in good condition should handle 500HP with a shift kit and good controller. The 4R has an electric actuated lock up that uses a solid shaft and offers more options.

That means a high stall converter is no longer a problem with heat going down the road since you can program or switch it to lock up when you want. Electronics also allow programmable shift points, adjusting shift firmness, multiple programs like street strip, and adjustable over drive parameters. I saw transmission controllers over $1,000 and found the Baumann for $400. I had not heard of any problems with the Baumann control so I figured this could make it affordable. I know how much work it is to install a large transmission like this in an older car so I started thinking about all the things involved. Should I just start with the better transmission? Knowing a good quality converter can be over $500 I did not want to buy that twice.

You know where I am going here. The converter, trans mount, yoke, and wiring are all different between an AOD and 4R70W. With all the work involved I went with the 4R to get what I wanted and do it once. One of the best options is a Mustang V6 since the 6 bolt bell housing is the same as Windsor V8’s and the shifter will point down. I wanted a 2001 to 02 trans since they have better valve bodies and still have speedometer gears if you need them. I did a search for used transmissions and found a 2001 with 50,000 miles for $220 and there were many in this price range in my area.



It appears the V6 Stang does not tear up transmissions and the low price reflects that since no one needs one and they get priced to sell. I drained the fluid, pulled the pan and replaced the filter. I also cleaned it up and put new front and rear seals in it.



My car never came with a transmission bigger than a C4 with a small bell housing and that is a sign the larger 4R will not fit without modification. If your car ever came with a big block or larger bell housing you have a better chance. So if I can stuff one of these in an early Fairlane it will fit in any other Ford. I was looking for a core 4R case to use for mock up since I figured it would be in and out a few times. When I was looking I had no luck getting one cheap.

My friend Tony did help me connect with Bob at Bendtsteads and he was willing to loan me an empty AOD case to use. If you ever need an oddball trans adapter check this out. They make very nice parts. [URL]http://www.transmissionadapters.com/index.htm[/URL]



Let’s deal with the issues involved with this swap. There will be electrical work just because a transmission controller will need to be installed and wired. There are exhaust fitment problems in probably every 1960’s small block car. From there it requires some changes to mounting and linkage. I felt I needed to start with the exhaust because it will affect clearance on everything else. If you use stock manifolds you can just have your local muffler shop make some new pipes when you get done. There are no known shorty headers to fit my car or I would have considered it and probably used them to greatly simplify this part of it. I had cut my shock towers to use a modified Hooker 6901. This is a header that fits many 1966 and later small block cars including Mustang, Fairlane, and Maverick. I wanted to use headers and these mods will work for most cars.



These are the 6901’s with the C4. A good amount of clearance but I still modified the cross member to enlarge the exhaust openings. I was fortunate to have a spare engine in the garage to test some fitment of parts. This is the first try of the headers. They could not actually be bolted tight to the heads because the collectors hit the sides. A bit wider than the C4.



There are a few aluminum tabs that will need to be cut off to make things fit. Two are at the front sides and two at the rear top that will hit the tunnel. This was the first try modifying the headers. I cut off the collectors, cut the pipes to the new angle, and fit the parts back together. This would actually work very well and is easy to do.



I was interested in trying to get as much access as I could without totally sacrificing power so I looked at a couple shorter collectors. This is what I ended up using.



I knew they fit on the garage floor so I just needed to be sure there was no problem under the car. They cleared so I welded them up.



I felt the headers were done. Time for my favorite header coating POR 20.



Next is the shifter. I have a Hurst floor shifter that I used with my C4. I really like it since it offers full ratchet shifting along with just put it in gear and go like stock. Also NHRA compliant. I did not find support for a 4R with this shifter or many others. I will show you how to adapt what you have to work. The shift position module is part of the 4R and will need to be used with any shifter.

It tells the controller what gear is selected and also has the start interlock and back up light switches. I did find the shaft is the same size as my C4 shifter arm. I removed my shifter from the car and clamped it to my transmission so I could test my experiments.



This was a test with a C4 arm to find the correct spot for the shift arm pivot point. I needed to do this to be sure the shift position was correct. If you have a shifter that supports the 4R just dismiss this. Next I found I needed to heat and remove the stock plastic bushing in the stock linkage arm. I sliced off a piece of black pipe and it was the perfect size to bush down the original pivot point. I just squeezed it in with a vise grip.


Here it is being tested



These are the brackets in their final form.



Here they are installed. It was tested with the shifter module in place and everything worked fine. This happens to be made of steel but you could do the arm with a 1” piece of aluminum to make it easier. It was all bent up in a vice so yes you can do it. The large hole was made with a unibit and this was at least trial number two. Start with the large hole and work back to the bushing in the stock arm. Just make sure all the detents in the shifter match the transmission and things will be good.



Next it needs to fit in that tunnel. Here is an AOD next to the 4R70W. The bell housing is longer on the 4R due to the converter having a clutch in it. The AOD I borrowed was empty so I used it for all the tests I could before actually putting the 4R in. It was nice to just lift it up and hold it in with one hand. Even when I was young I could not hold one of these up. The trans mount on a 4R is to the rear almost an inch more than an AOD and inches more than a C4.



I guess I could have cut and modified the floor to fit. Then again it is covered with carpet on top and hidden by a trans on the bottom. A two pound hammer will allow all the “clearance” that will be needed to the tunnel to get it in.



It is time for the cross member now that I know where every thing else goes. The stock mounting rails could have a couple inches added to them to move the cross member back a little. The cross member would also probably need a little more exhaust clearance. I was planning on adding sub frame connectors to my car so I figured now was the time. I would use them to support the cross member. I welded some tube into them about in line with the Mustang transmission mount.



The connecters are 1.5 X 3” and the cross member is 1 X 2”. I used a hole saw and exhaust tubing to recess the trans mount bolts.



I originally clamped angle to the sub frames and adjusted it up and down to get the same angle as the rear end flange. When everything was correct I marked the holes for the cross bolts and welded the cross member to the angle.



I added a little extra bracing since this is a heavy transmission. As you can see I also added fittings in the pan for a drain and temp sensor and I am starting to run the exhaust. The low spot in the pan is where the fluid pick up drops down. The stock speedometer cable also bolts right in. Do not let this scare you away. If you modify the stock parts a little you can still get it in.



Physically there are a couple more parts to install. You can use the stock converter on a stock type install. I used a Precision Industries Stallion higher stall lock up converter. When you buy a flex plate you will be choosing between a 28 or 50 oz imbalance on a stock application. Check your application but it was near 1980 that it switched from 28 to 50oz. All will be 164 tooth flywheels for this application. I found a Ford Racing 164 tooth 28 oz flywheel on line and that is what I used.



This does not quite fill up the bell housing and is a billet lock up that is about 20 pounds lighter than stock. This is where you need to decide where you will spend your money. If you do this swap for fuel mileage and reduced wear I would use the stock converter. I used 4.10 gears and with the low first gear the stock converter would still be a big improvement. 4.10’s with over drive is still less than a 3.00 stock ratio with no over drive. With a converter like this it time for sticky tires. Next is cooler lines. If you do not do much of this you may want to farm it out or just get fittings and run braided hose. I used steel lines and managed to squeeze them in in one piece.



Another part to mate this new transmission to the rear is a drive shaft. I wanted an aluminum shaft and my local vender of choice did not do them. I ordered from Shaftmasters. All USA parts and solid U joints if you want strong stuff I would recommend them. Light and the construction is very good. Driveshafts - Custom Made Driveshafts- Aluminum Driveshafts and Steel Driveshafts by Shaftmasters Inc



Not really part of the install but I wanted a drive shaft safety loop. My car does not need one for the times I run but I did buy materials to make it NHRA legal. It spans two seat bolts and connects the tunnel to add a little to the sub frame connectors.



The last little part to install is the throttle position sensor. This is like Voo Doo to old school car guys like me. It does not need to be. If you have a carb here are some simple bolt on examples. If you have fuel injection it looks like you can use that TPS.





I had thoughts of U pull cheap auto parts to do this. After doing it I would just suggest buying a kit unless you want to save a couple bucks and have a lot time on your hands. I pulled a throttle body off an Escort thinking I would cut it down and use it. They look small until you try and make them fit some where. I did end up adapting one. This is my home made shaft.



I ended up using flanged ball bearings and brackets to adapt all this to fit. I would buy a kit with what I know now. Here is my final mechanical linkage install. I used the trans kick down locked in.



Looks like it is time to finish this. The next step is electrical. I have the Baumann harness and if you have questions about your wiring abilities I would recommend buying it. All the wires are labeled so there is no question where they go. The connectors are there from the trans to the controller. The wires are long enough that I could mount it under the rear seat with the wires coming in the fire wall. My transmission did come with a harness and with the wiring diagrams available I would not have had a problem doing my own. Another note would be to be sure you have the correct dip stick. My trans did not come with a dip stick and it turns out I had one from an AOD. The levels are not the same and I was chasing leaks due to over filling.


[URL="http://www.becontrols.com/tech/ch3aodeupgrade.htm"]http://www.becontrols.com/tech/ch3aodeupgrade.htm[/URL]


The new Baumann controllers have a USB port so almost any one can connect to and program this. I have an an older controller and it needs a serial connector. I use a USB to serial connector. If you don’t mind moving a computer into the garage this is easy to do without a laptop computer. You can down load the software and it looks like the graph above. A mouse click will move the shift curves. You will also enter your gear and axle ratio on another screen so the trans knows what to do. I have seen some adds that claim only their product is simple. Does moving your mouse on a graph seem that difficult? It is easy to use and there is help available. A switch can also select two different tunes. From my experience I would never suggest swapping in an AOD over a 4R70W. It is a fair amount of work so start with a much better trans. This trans can totally change a car. With 4.10 gears it locks up and goes down the road at lower RPM’s than my C4 and 3.25’s. This is a great swap. Now I need Baumann to give me a new USB controller for a test. Hint hint . These are good transmissions and this has been one of the best things I have done to the car. The car is faster, gets better mileage, and is much quieter going down the road. Here is a little three gear burn out with the new set up.


[URL="http://www.youtube.com/watch?v=410CMNGu3_E"]http://www.youtube.com/watch?v=410CMNGu3_E[/URL]
 
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#4 ·
Hey great article,

So do all of the 2001-2002 V-6 Mustang 4r70w trans have a mechanical speedo gear? I currently am running an AOD. Love the mileage. Don't like how it shifts. I like the possibility of having different programmable shift points.

Larry
 
#5 ·
I can only go by what I have seen and heard. I know of 2002's with the gear and have heard by 2003 they were gone. I guess if I was going to buy one I would look down the hole and check. It is easy to see it. The new Optishift by Baumann has a display that can show vehicle speed. The trans has its own speed sensor. Mount it in a visible location and it is your speedometer. It is a good swap.
 
#8 ·
I emailed Bendsten's and they said the FE to AOD trans adaptor would work with any small block ford trans and also they had modified it to adapt to any modular motor trans (4.6, 5.4, V10). It's good to know there are some alternatives for the FE, a little pricey but what isn't for an FE.
Mike
 
#10 ·
Larry: if you want to keep the AOD & fix its "shift when i want to " attitude there is a great fix.
Lentech Automatics makes a valve body that totally changes the AOD's character. Gives you full manual control over 1,2,3 shifts & a simple switch you can mount on the shfiter, floor or dash to control OD on/off.
Or leave it in D & it shifts normally,
With Lentech;s valve body & a hardened shaft you have a very sturdy AOD.
 
#12 ·
Got my 4r70w a few months back and purchased the Baumann controller and a 2500 stall converter. Hopefully will be installing it in my wagon in the beginning of January. Wahoo, cant wait. I will be pulling the AOD out of it. Been a good trans. But, looking forward to that first gear.

Larry
 
#14 ·
Larry you should have asked before you bought one. :) Almost two years but you are finally ready. I had my junk yard TPS fail this spring but have had no problems with the trans or the swap. I was going to play around with the tuning a little more but it is one of those things that is not causing a problem so I have not done it. I would start with a new TPS and I did get the wrong trans yoke. I had a slight vibration and it seemed my yoke was a little short. Picked up one from a Mustang that was different, a little longer, and cured the problem with a new bushing. If you run gears 3.73 or lower I would definitely add a pressure feed line to the rear tail shaft bushing. I found that out the hard way when I was chasing down the vibration and found too much play on the tail shaft. I used a brake line from the pressure tap to a fitting feeding the tail shaft bushing. I think it was a 0.050 restriction hole? If I would have known and fixed those problems before I would have had no problems. It may still be the best mod to the car. Good luck.
Mark
 
#15 ·
I hear that the trans yoke is bigger on a 4r70w than on a C-4/aod trans. Not much of a difference but if you go with a C-4/aod it will leak. Is that true? From what I understand the aod/aode/c-4 measures 1.5". Where the 94+ 4r70w measures 1.606". What year trans is yours out of? Mine came out of a '99 Mustang v-6. Most of the stuff form what I understand is the updated stuff in that year. Where can I find that tail shaft mod at?

Larry
 
#19 ·
Great article. I sure wish that I had gone with that tranny instead of the AOD. Even though the Lentech valve body makes it far better than stock, the abilty to control it more, seems the way to go.
 
#20 ·
Well, I had to take my transmission in to have it rebuilt. The guy I bought it from scammed me on it. Oh the joys of craigslist. Should of known better. Oh well. Now I have a freshly rebuilt trans with upgraded components. Going to be fun. Can't wait to see what that first gear is like. Pick it up today.

Larry
 
#22 ·
Cool, eh? Just by making minor adjustments or a flip of a switch (depending on the controller), you can make it shift so hard it will take your teeth out, or so soft it's like Granny's stocker. An AOD-E with upgrades, 4R70W, or 4R75W with the famous "J-mods" outlined by Jerry Wroblewsky (Ford engineer that was part of design and testing) and a good controller - it's so solid and fast they don't even get any handicap for class racing against manual transmissions like autos used to.

Yeah, some stick-shift guys get pretty riled-up when you show them how these autos can be faster and more consistent on the strip than a manual. You simply can't shift any more accurately than a computer. But, if you want to "row" it down the road with the shifter, you can still do that too. ;)

David
 
#23 ·
The controllers are pretty cool. I had the shop put in Alto red eagle clutch packs with kolene steels. I am using the US Shift controller. Nice that I can control the shift points. And can flip a switch and have a totally different pattern. I did not do the j mod. I have heard about it though. I have my trans set according to their normal shift pattern and was surprised. I am running a 2500 stall. Normal acceleration it shifts nice and smooth. Get on it at half throttle wow. To the floor hold on. Haven't programed in the aggressive shift pattern yet. Going to be interesting.

Larry
 
#24 ·
Love the article. Thanks. I am putting a 4R70W behind a new mustang 5.0 in a 67 Galaxie. I haven't gotten to the wiring yet, but I was able to use the original crossmember and mount with no modifications. Even the 46 year old bolts screwed right in to the 4R. Now I am trying to figure out how to use the column shifter to select the gear. It looks like I will be able to use most of the original parts and make an adapter plate.
 
#33 ·
David this is what I was going to use. but it puts my shift arm lower than my pan. So it will not work with what I need it to do. My car is pretty low and I don't want to hit the ground with my shifter. form what I understand the Winters sidewinder will work with my trans for what I need it to do. May make a custom console to mount it in my car. I want it to look somewhat stock looking.

Larry
 
#34 ·
You use what you need and cut off the rest. The arm length to match your shifter is whatever it is. It can't be shorter, and it does not have to be longer. I'm not pushing for you to use this option, just saying that a downward arm for a "push-to-Park" floor shifter has to be a certain length no matter what. Just cut off the excess. The only alternative with that style shifter is to run a longer cable around from the front and bracket it to the bellhousing, to use an "up" shift arm. That's probably what I'll do on the next project with a floor-mount gate shifter I have.

David
 
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