5.0 swap? Consider using the 4R70W !! | Ford Explorer Forums - Serious Explorations

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5.0 swap? Consider using the 4R70W !!

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For those of your considering swapping in a 5.0L V8 and AOD in your explorer, consider using a 4R70W (aka: AODE-W) wide ratio electronic controlled transmission instead of a traditional AOD.

For those of you who don't know, I used a AOD (automatic Overdrive) in my Explorer V8 project. The AOD's torque conveter locks up in 3rd and Fourth gear by the use of a one piece lockup shaft in the transmission. This means that the torque multiplying effect only exists in 1st and 2nd gear. After completing my 5.0 swap, I wish I could have used an A4LD rather than the AOD. lol. The AOD is controlled by a mechanical linkage called a throttle valve cable. This cables tells your transmission how to shift......and it does a clunky job at best. I tend to drive in 3rd (D) instead of (OD) to avoid the constant "Hunt" that this inconsistent transmission resluts in. Imagine your racing somebody, as soon as you hit third gear, Your torque converter manually locks, shooting your RPM's down, which allows you to only build RPM dependent on your speed. This 3rd gear lockup is also bad for driving around in the city. Say, your driving in stop and go traffic, You get up to 25 MPH, and the cars start braking in front of, you let off the gas. At this point, the low TV pressure will enter the transmission in to a "Coast" mode, causing it to shift in to 3rd gear locked "CLUNK" Now, if the traffic starts accelerating, you would have to press the gas pedal down causing the motor to bog, to get it back in to 2nd gear.......
AOD = CLUNKY SHIFTS. The mechanical linkage can not predict the your future actions.

Now some people who live and die by the AOD have some fixes for this problem.
Fix #1: Install all the internals from a 4R70W in to the AOD to make it wide ratio & give it the 2in OD band. While this is a nice little mod, it still doesn't address the Torque Converter lockup issue.

Fix #2: Switch over to a NON-Lockup torque converter and one piece input shaft. Well this is just super!! Now I have to drive on the highway with an open torque converter at 5,000 RPM........ Good for RACING, not for the daily driver.....No thanks on this one.

But fear not......... THERE IS LIGHT at the end of the tunnel. And it is known as 4R70W.
The 4R70W looks just like the AOD and AODE, except for the slightly larger Bellhousing. The 4R70W has an Electronic Lock-up converter. This means it has the ability to lock and unlock allowing you to maintain the "torque multiplying effect" in any gear you want.

Here is an example of the 4R70W shifts:
1st gear: OPEN Torque COnverter
2nd gear: Optional Locked torque converter
3rd gear: Open torque converter
3rd gear: Optional locked torque converter
4th gear: (OD BAND) Open torque converter
4th gear: (OD Band) LOCKED torque conveter

This gives the versatility of seven different shift points compared to the AOD's four.

The 4R70W utilizes the Engines Throttle Postion sensor to more precisely and electronically control line pressure. It can even be used on a carburated 302 if a aftermarket sesnor is installed. In Conversions using a EEC-IV computer system, you can use a Baumann TCS from Baumann Engineering to operate the unit. Also, Since the 4R70W is the same shell as the AOD, you can use the Advanced Adapter tailshaft conversions made for any year AOD. The Baumann TCS computer that controls the 4R70W allows you to even input your tire size and rear axle gear ratio to further customize your shift points with the use of a labtop or desktop computer. Instead of using a mechanical governor, the 4R70W instead utilizes an output shaft speed sensoe seperate from the tailshaft/transfer case VSS sensor to further predict shifting.

So, my suggestion for anyone wanting a smooth shifting transmission to be used in a "road" or daily driver vehicle, look in to the 4R70W.

Think a 4R70W is expensive? Nope. I got a brand new model year 2000 4R70W with new torque converter for $699. If you plan on searching for an 4R70W here is soem advice for finding one. Try and stick to a model year 1998 and up 4R70W.......Ford upgraded to a mechanical diode and made a few other revisions that compliment the tranny. Do not get a 4R70W that came behind a 4.6L V8. This will not bolt up to a 5.0 "windsor bolt pattern. The 4R70W is used in many Ford Hi-performance applications including the new GT-40 concept, Cobra Mustangs, 4.6 Expeditions, 4.6 F-150's etc. You can find 4R70W's with the 5.0 windsor bolt pattern on 1996-2001 Explorer V8's and 1994+ F-150 V8's and on some other 3.8 V6 models....... Unless you are running a wiring harness that orignally had a 4R70W behind it, you must use a Baumann TCS computer, it is very SIMPLE to hook up (no complex wiring, just hook it up to your TPS and cehicle power and your set) Information on the computer can be found at www.baumannengineering.com
Hope this Helps!

Al - Phoenix, AZ asp84@earthlink.net

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Standard Ratio AOD Wide Ratio 4R70W

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

:redexp: :D :redexp:

too bad its not a computer controlled lock up like the A4LD, I plan to wire my A4LD up so I can controll the convertor lock up, I took get sick of the :CLUNK' around town when that sucker lokcs/unlocks all the time...

errrrr........lol! The 4R70W is COMPUTER CONTROLLED LOCKUP! A switch is used to manually lock and unlock the Torque Converter as needed. The switch can also be used to switch different user defined programs,

4R70W is = Electronic computer Controlled
AOD= Mechanical

asp84, I cann't believe that your having so many problems with your tranny. I have personally found my transmission quite nice and very easy to drive. I am using the the modified AOD with the wide-ratio gear set, so maybe this is where the difference lay. I have not found my tranny clunky or tough to drive when the torque converter locks up. I have plenty of power when I need to excellerate in traffic, and it shifts with firmly.

The problems with my tranny is a result of having it re-built at Ford. The AOD is at the top of my Sh*t list!
My AOD is standard ratio, but it does have the A+ OD servo, Alto direct clutch packs, Kevlar OD band, newer valve body, etc,, etc.

The transmission is not really clunky, I should say.....it shifts firm from all the increased clutch packs and band.

The 4R70W kit in your AOD probably makes a big difference. But still......... I would rather have the ability of an auto un-locking torque converter. That ability gives the 4R70W a "feel" of 7 different shifts, compared to the AOD's four. I really feel that there are a lot of times where it would be beneficial to have the torque converter un-locked during city driving or when climbing a steep mountain pass. (in third and fourth)Don't you??


Yes I would agree with you there. It would be nice to unlock the converter on a long steep hill or in the city. I need to find a hydraulic diagram for the AOD. there has to be a way to modify it so that the torque converter lock up can be controlled.

I have the same AOD tuning issues


Great post! Now I know I'm not the only auto 5.0 conversion out there :)

I'd have to agree with all your statements. I too have been trying to "tune" a JET built AOD to be a daily driver. I have one last trick to use a Mustang HO governor to try and help with shift points. I suspect I will still have the issues between D and OD. I also drive in D most of the time.

After reading about many original bronco 302 conversions the AODe-W and the bauman computer sound like the way to go.

I've already got $2,500 in my JET trans. I may sell it and try to recoop some of my $s and go with an AODe-W aka 4R70W.

I'm running 5.0 HO with AOD from an F150 and 33x12.5 and 4:10 gears.

Lesson learned.

Thanks.......My 4R70W is sitting waiting for me to find some time to install it!......I can't wait1

asp84 How goes the tranny swap?

I wanted to get some feedback from you before I
go the AOD-E route.


OH man here we go.....

Joe let me help you, let me know when you are gonna drop that sucker, we dont need it falling on your forehead........

Brett and I will help.......

Joe, I still don't have it in yet. ( I have kinda got delayed) Today I am going to my garage to start taking apart my 4R70W. It needs to be dissasembeld before installing the Advanced Adapter Output shaft.

I have made some progress with the computer system though. I just installed my explorer front accesory dress and camshaft trigger wheel/sensor, in preperation for the EEC-V computer system, which will control the 4R70W. Hopefully I should be looking to install it later this week or weekend. Stay tuned.


I want a bigger engine in my sport maybe down the line ill throw in a 5.0 ?!?!


Ya, I don't want to crack my bell housing again. You will be involved. I wanted to see how Al's goes then make some decisions.

Hey Al,

Can you explain the need for the AA output shaft? Does the original AOD AA transfer case tail shaft work on the AOD-E or do I need to replace it?

Well just let us know....and happy thanksgiving! I am shooting for Moab in the spring..........

As luck would have it, you don't need to replace the AA output shaft to swap in an AOD-E for an AOD. The output shafts are interchangeable. (there are some extra oil passages on the AOD-E but the AA shaft is already modified)

I maybe wrong on the oil passages of the AA shaft if it is older, I know that my shaft had the extra oil passages. But then again mine was only purchased last year.

Here is an excellent source of AOD and AOD-E information. AOD information


Ok, not sure I have this down...
I have an AOD with the AA adaptor for the 1354 transfer case. Can I re-use the AA AOD tail adaptor from the AOD on the AOD-E. Also, does the AOD-E shaft inside the tail need to be swapped with and AOD shaft?

Ya, I'm a bit slow...

I reread my post and found that I wasn't too clear. The AA tailshaft that you have in your AOD should work fine in the AOD-E. But to be on the safe side I suggest refering to AA to make sure. I know that the shaft I purchased was adaptable for either tranny, but I can't say if the older shafts are capable or not. This is the only shaft that needs to be changed to adapt to the 1354 transfer case.

Yes, you can re-use any year Adavanced Adapter tailshaft for the AOD and 1354 in any 4R70W and AODE. You will need to purchase a special pin and sleeve to block the oiling passages.

On Tuesday I tore down the 4R70W and re-assembeled it. Not to hard.

Good Luck.

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He guys what rpm torque converter are you using? I understand the stock unit is 1600rpm stall. Does the stock converter work well?