4R70W

The 4R70W is a revised version of the famous Ford’s long-running 4-speed AOD (automatic overdrive) transmission that appeared in the ’80s. Experts believe a robust performance transmission adds more power to vehicles like the 4th generation Ford Mustang. In addition, it was a much-needed answer to the fuel efficiency issues that plagued the United States during the 1973 oil embargo crisis. General Motors and Chrysler saw the remarkable success of Ford’s 4R70W performance and followed almost immediately with the unique and respective versions. The nomenclature of the 4R70W breaks down this way:

• 4: Four forward speeds
• R: Rear-wheel drive
• 70: Torque rating x 10 (holds up to 700 lb-ft)
• W: Wide-ratio

You need to know the fundamentals of the 4R70W performance transmission.

Overview of the 4R70W Performance Transmission

As mentioned earlier, the 4R70W transmission is a significantly enhanced AOD with a wide gear ratio and rear-wheel overdrive. In addition, the 4R70W transmission’s first and second-gear ratios are higher. This has given rise to several benefits in vehicles mounted with this high-performance transmission. Drivers of the 4R70W performance transmission will enjoy better mechanical advantage, lower fuel consumption, and even better take-off acceleration. The strength of the gearset is also enhanced. The 4R70W features a ‘wide ratio’ gear set. In 1998, the intermediate one-way clutch was replaced with a mechanical diode.

4R70W Specs and Ratios

The 4R70W transmission’s case material is aluminum and features a Motorcraft FT 105 transmission filter. It has a maximum torque input of approximately 516 lb-ft. The 4R70W transmission’s gear ratios are as follows:

• First gear: 2.84:1
• Second gear: 1.55:1
• Third gear: 1.00:1
• Fourth gear (overdrive): 0.70:1
• Reverse: 2.32:1

The automatic overdrive electronic control transmission (AODE) was launched in 1991. This particular transmission is different from the AOD in several ways. This includes:

• Computer controls
• Torque controller
• Front pump assembly
• Single input shaft
• New valve body

The following are the respective gear ratios of the AODE:

• First gear: 2.40:1
• Second gear: 1.47:1
• Third gear: 1:2
• Fourth gear: 0.67:1

As you can see, their gear ratios are significantly different when compared side by side. Furthermore, note that valve bodies and cases of the 4R70W, AOD, and AODE are also different. This is why it is practically impossible to switch the valve bodies of these units, stipulating specificity. However, it is possible to take the gear train of the AOD and shove it into an AODE and experienced zero issues.

4R70W Facts

The ’70s birthed a slew of fuel-efficient vehicles, but the manufacturers had to sacrifice some performance and speed features exhibited by the older models. At the time, driving fuel-efficient cars was economically and environmentally friendly, making it possible to cover many more miles but with less fuel. Therefore, when oil prices rose by 400 percent, it became crucial to manufacturing fuel-efficient automobiles. Ford rose to the occasion in 1980 by creating the 4-speed AOD. This transmission had several features found in old designs, despite its newness. Nevertheless, it was the perfect replacement for many older transmissions created by Ford, including the FMX, C4, and C5. The AOD was similar to the 3-speed FMX automatics. These transmissions had a few components in common, including the Ravigneaux gear train, etc.

4R70W Pros and Cons

While the 4R70W may be a performance transmission, but it is not without issues. For instance, here are some pros and cons of the 4R70W transmission.

Pros

The 4R70W transmission comes with a significantly boosted overdrive band, including the following:

• Improved pinpoint precision control;
• Solid input shaft;
• Enhanced front pump.

Another significant benefit of the 4R70W transmission is its remarkable compatibility with most Ford automobiles with minimal work or modification. Moreover, this transmission easily fits several older vehicles, furnishing them with magnificent performance and efficiency.

Cons

When you overload the 4R70W transmission, you’re courting problems, as torque and power have a pronounced limit. Exceeding these limits can cause many various transmission problems. Other issues plaguing the 4R70W transmission include:

• Delay in lock-up;
• Intermediate clutch failures;
• Rough 2-3 shifts;
• Significant loss of forward gears and 4th gear;
• Considerable shudder in reverse or delay in reverse;
• Pump noise and leakage of the front seal;
• Significant loss of 2nd and 3rd gears.

Every automatic transmission worth its salt requires consistent maintenance. The 4R70 transmission is included. Maintaining this robust transmission regularly guarantees its longevity. This is why it is highly recommended that a certified expert looks into this robust automatic transmission during installation. If all these issues are eliminated, it will go a long way in boosting the overall reliability of your 4R70W performance transmission while providing the much-needed power boost.

Identifying the 4R70W Transmission

Many need to learn how to quickly identify the 4R70W or know whether or not they have one. However, you can identify the 4R70W transmission by looking at the following:

• Electric plug and cable. Both 4R70W and AOD transmissions come with a plug on their rear housing on the driver’s side. The electronic control cable plugs right into this particular spot in the unit. This differentiates the 4R70W and AODE transmissions from the older AOD units.
• Lightweight components. Compared to their predecessors, 4R70W and AODE transmissions come with an aluminum front pump against the cast iron that the AOD has. The AODE and 4R70W transmissions are also lighter due to their stamped steel clutch packs – which are lighter than the cast steel of the AOD.

These are just a few identifiable aspects that differentiate the 4R70W transmission from its older counterparts.

4R70W Performance Key Takeaways

The 4R70W performance transmission is one of the most outstanding stock transmissions on the market, guaranteed to perform even better in vehicles like the 4th generation Ford Mustang. The 4R70W is best for performance driving or drag racing enthusiasts, and good speed is 100 percent guaranteed.

The Ford 4R70W transmission history and evolution has been an interesting one. It began with more fuel-efficient cars, given the high gasoline cost to run these vehicles. There was also a low supply of fuel, which made it expensive to drive heavy automobiles, large-displacement carbureted V-8s, 2- and 3-speed straight-drive automatics, and other cars.

As such, car manufacturers, including Ford, had to include components that will make cars run longer but with less fuel. One such modification led to the Ford 4R70W transmission launch, an upgrade to the Ford AOD transmission. Here is all you need to know about the 4R70W’s history, evolution, and how it differs from the AOD transmission.

History of the Ford 4R70W Transmission

The 4R70W denotes:

• • Four-speed
  • Rear-wheel drive (RWD)
  • 700ft-lbs (input torque in ft-lbs x 10)
  • Wide-ratio

The history of the 4R70W transmission can be traced to Ford’s automatic overdrive (AOD). AOD was launched in 1980, and it was the first domestic automatic overdrive transmission targeted at providing fuel-efficiency. This transmission featured hydro-mechanicals and direct overdrive lockup to mitigate wasteful slippage. The AOD also featured Ravigneaux geartrain components that made it rugged. However, there was still a need for improvement since the AOD had durability problems, especially in its overdrive unit.

Accordingly, the AOD Electronic Control (AODE)/4R70W was launched in 1991 to tackle these problems. The AODE was also meant to provide a more cohesive functioning of the engine and transmission. It is worth noting that the name AODE was maintained between 1991 to 1992 before introducing the 4R70W (which is also an AODE) in 1993. The 4R70W was fitted behind the 4.6L dual overhead cam (DOHC) V-8 in the new Lincoln Mark VIII and some F-Series trucks launched in the same year.

Functions of the Ford 4R70W Transmission

The 4R70W is also an AODE transmission; as such, its features are like an AODE. Some of these features help to identify the transmission from an AOD, and they include:

1. Gear Ratios

• • First: 2.84.1
  • Second: 1.55:1
  • Third: 1.00:1
  • Overdrive: 0.70:1
  • Reverse: 2.23:1

The 4R70W differs from the AODE in terms of gear ratios. This transmission has lower gear ratios in first and second gears, which brings about improved acceleration. The 4R70W planetary gearset, with its improved first-gear ratio, also offers better acceleration. In line with that, the 4R70W gearset can be swapped into an AOD if you are out to get better 2.84:1 to 1.55:1 1-2 upshift and holeshot.

2. Locking Torque Converter

4R70W uses a locking torque converter, which differs from the split-torque overdrive unit lockup feature evident on the AOD. According to Ford, a locking torque converter was to build a more cohesive engine and driveline package. A throttle tip-in while you are in overdrive, causes the converter clutch to disengage, and the latter leads to improved acceleration and torque multiplication.

3. New-and-Improved Valve Body

You will find a new-and-improved valve body in the 4R70W transmission. There are also two computer-controlled solenoid packages, and these have two shift solenoids and a converter clutch solenoid. Ford claims that this valve body is thicker, which offers more strength and durability. These valves are also made of aluminum, unlike steel in AOD, to offer decrease weight and improved sealing. Other components of the 4R70W are:

4. Front Pump

The 4R70W has a front pump made of aluminum, and it also has a steel rotor to provide better flow at idle and increased lubrication and pressure.

5. Speedometer Drive

Given that the 4R70W is an AOD-based transmission, it also features a speedometer drive.

6. Backup Light/Neutral Safety Switch

The 4R70W transmission has a backup light/neutral safety switch. The output shaft speed sensor is located above the switch, and it functions alongside the PCM to enable the engine and transmission function cohesively.

7. Output-Shaft Speed Sensor and Plug

The 4R70W has its output-shaft speed sensor and plug stationed on the driver’s side. On the other hand, the multiplex plug serves as a backup light/neutral safety switch on the transmission driver’s side.

8. 4R70W Multiplex Plug Connection

The 4R70W has a multiplex plug connection, which enables controlled AOD to operate seamlessly with engine operation. A TV cable is not used to move out of adjustment but electronics to offer precision function.

Evolution of the Ford 4R70W Transmission

Better transmissions are being made from older ones, which does not come as a surprise that the 4R70W has evolved. In 2003, the 4R75W and 4R75E were launched as better variants of the 4R70W. These modified versions have better computer control, given that they use input and output shaft sensors. What is more, better improvements can be attributed to shifting power via the valve body. These enhanced variants also have a more durable overdrive drum, improved front pump, and torque converter.

Other improvements made on the 4R75W and 4R75E include:

• • Improved input shaft sensor.
  • Gearset durability and torque capacity improvement.
  • Refined vehicle speed sensor to fine-tune performance while driving.
  • Twenty-four tabs on the 4R75’s ring gear to offer for more precise shift control.
  • More programming in the powertrain control module (PCM) to allow use in drive-by-wire vehicles.
  • The 4R75W and 4R75E feature two shaft sensors for input and output shafts. However, the 4R75-series transmission comes with a different main case to support both sensors.

The Bottom Line

The Ford 4R70W history and evolution show how far it has come and the updates it underwent to be better than its predecessor. It uses fuel efficiently and makes room for other improvements, which makes your driving experience more enjoyable. Although this is an old transmission, it is still a formidable competitor to newer transmissions from Ford.

The fourth generation Ford Mustang can be made faster and more reliable by carrying out some performance upgrades instead of adding more power. It may involve installing a performance automatic 4R70W transmission in a bid to change the stock unit that came with the vehicle.

While a stock transmission comes directly out of the manufacturer’s warehouse, it may be unable to handle your need for speed. The latter can be tied to the Two Valve it features, which may leave the car struggling to get enough RPM (Revolutions per minute). Remember, if it gets enough RPM without struggling to, it takes it one step closer to being a faster ride.

Accordingly, the modifications or boost you can give the Mustang will provide a nose that is significantly higher than what a stock Two Valve can. The aim is to meet or exceed the original equipment manufacturer’s (OEM) measured standards.

But first…

What Is a 4R70W Transmission?

The 4R70W was launched as an improved version of the AOD-E transmission. And compared to the AOD-E, the 1st and 2nd gear ratios of the 4R70-W are numerically higher. This resulted in:

• • Better gearset strength
  • Lower fuel consumption
  • Better take-off acceleration
  • Better mechanical advantage

This Ford transmission is also an upgrade to the AOD, a 4-speed automatic overdrive transmission, aimed at tackling fuel efficiency issues. Upon its launch, the transmission featured a “wide ratio” gear set, however, a mechanical diode replaced its intermediate one-way clutch in 1998.

Often times, upgrades to the Mustangs with the 4R70W transmission are made possible using 4.10 rear end gears, shift kits, and a performance torque converter.

4R70W Transmission Specs

The 4R70W transmission specs are:

• • Transmission: Ford 4R70W
  • Predecessor: Ford AODE
  • Type: 4-speed overdrive automatic transmission
  • Wide gear ratio
  • Rear-wheel drive
  • Case Material: Aluminum
  • Max Input Torque: ~ 516 lb-ft (700 n-m)
  • ATF Type/Spec: MERCON V ATF (Motorcraft XT-5-QMC)
  • Transmission Filter: Motorcraft FT105

Gear ratios:

• • First: 2.84 :1
  • Second: 1.55 :1
  • Third: 1.00 :1
  • Overdrive: 0.70 :1
  • Reverse: 2.32 :1

4R70W Transmission-Infused Vehicles

Cars that used the 4R70W transmission include:

• • Ford F-150 Series pick-up trucks, E-150 Series vans, Expeditions, Explorers, Crown Victorias, Thunderbirds, and Mustangs
  • Lincoln Town Cars and Mark VIIIs
  • Mercury Grand Marquis, Cougars, Mountaineers and Marauders

Specifically, the years this transmission was used are:

• • 1993–1998 Lincoln Mark VIII
  • 1993–2003 Ford F-Series
  • 1994–1997 Ford Thunderbird
  • 1995–2004 Ford Crown Victoria
  • 1996–2001 Ford Explorer
  • 1993–2004 Lincoln Town Car
  • 1994–1997 Mercury Cougar
  • 1995–2004 Mercury Grand Marquis
  • 2003 Mercury Marauder
  • 1997–2004 Ford Expedition
  • 1997–2001 Mercury Mountaineer
  • 1996–2004 Ford Mustang
  • 2004–2005 Rover 75 V8

On the other hand, the 4R70W was not the only transmission for Mustangs.

This is because Ford had launched a range of transmissions since 1979 for Mustangs, and as such, you can find a wide variety of these transmissions. Other models include:

• • C4 Transmission
  • Automatic Overdrive or AOD Transmission
  • AOD-E Transmission
  • 4R75W Transmission
  • 5R55S Transmission

How to Boost Performance in a 4th Generation Mustang

A performance automatic 4R70W transmission can be used to boost the performance of a fourth generation Mustang. This is because a well-built automatic transmission and a torque converter with the right specs can give you car a good boost.

In that regard, this boost can be made possible by replacing the stock automatic-equipped Two Valves in the ride. Why is that?

The stock transmission is not known to offer an out-this-world performance due to the fact that a stock converter does not really perform to its best when it lacks low-rpm torque. In the same vein, the slushy shifts it makes shows that it is spending more time between gears rather than driving forward.

Nonetheless, some stock 4R70W-equipped light bolt-on New Edge GTs move speedily and even cover the quarter-mile in the low 15-second to high 14-second range. Much more, this performance is carried out seamlessly.

Accordingly, what you need to begin, is the right aftermarket parts to bring out their best performance. It all begins with a transmission upgrade.

Advantages of a 4R70W Transmission Upgrade

An automatic transmission upgrade can help with your ride’s performance, hence, it is a good place to start instead of adding more power. Here are some benefits that can be obtained from this transmission upgrade:

• • An upgrade will enable the car to shift gears faster and hold more power.
  • The performance converter will be able to move the car into the powerband sooner.
  • The upgraded components will be able to withstand the converter being locked under WOT.

Consequently, adding more power is not the most ideal solution since a good number of stock automatics tend to fail in short order once more power has been added. It could mean more problems in the long run, but it can be avoided by starting from the basics through a transmission upgrade.

4R70W Transmission Problems

Asides from upgrading your transmission to get more speed, it can help to improve its reliability. This is because there are certain 4R70W transmission problems that are prevalent with the stock transmission. For starters, the stock 4R70W transmission was susceptible to the following issues:

• • Harsh 2-3 shift
  • Delay in lock-up
  • Loss of second gear and third gear
  • Loss of fourth gear and forward gears
  • An intermediate clutch failure
  • Delay in reverse or shudder in reverse
  • Leaking of the front seal or pump noise

The Bottom Line

The 4R70W is a good transmission, however, it can be made to perform even better in a fourth generation Ford Mustang. In this case, the usual route of adding more power is not employed, instead, a transmission upgrade is carried out to ensure that whether you’re out for drag racing or performance driving, you can get good speed.

What’s more, an upgrade from the stock transmission will eliminate certain issues that were prevalent in it. These issues include loss in gears, delays in lockup, clutch failure, and many others. Once each of these is eliminated, it can go a long way to improve the reliability of your transmission and also help it to offer more power boost.