August 2019

Modern cars have become more complicated from what they were before due to the launch of new technologies. These technologies have led to features such as dual-clutch, CVT’s, semi-automatic, and automatic transmissions, transmissions built with as high as ten gears, among many others.

Unlike manual transmissions that can disconnect the engine from the transmission using a clutch, the same cannot be said for automatic transmissions. The reason is, automatics are devoid of clutches and instead, rely on the torque converter to keep the engine turning while the gears and wheels in the transmission come to a halt.

Thus, the torque converter in cars with automatic transmissions is very important in any vehicle today and if your transmission is blown or you’re experiencing symptoms of a blown transmission, then the culprit could be its converter as we’ll soon take a look at.

What Is a Torque Converter?

A torque converter is a coupling that helps in the transfer of power or torque from the car’s engine to its transmission. Also, this coupling relies on fluid hydrodynamic in a bid to enable an independent spinning of the engine without the help of the transmission. For instance, an idling engine when a driver gets to a stoplight reduces the torque that is passing through the torque converter.

However, this amount of torque is still enough to require pressure on the brake to stop the car from creeping. More power or torque is then transmitted to the wheels when engine’s speed increases and more fluid is pumped into the torque converter as a result of the brake being released, and the gas is stepped on.

Basics of Torque Converters

As already stated above, the torque converter enables power or torque to be transmitted from the engine to the transmission. The torque converter consists of three parts, and these are the impeller, turbine, and stator. Let’s take a closer look at each:

1. Impeller

The impeller or pump is the first significant component of a torque converter. This unit contains fluid, and it spins simultaneously with the engine’s crankshaft. As the impeller spins faster, more force is exerted on the fluid, which enables it to flow through it quicker and harder.

2. Turbine

The next assembly of blades within the torque converter is the turbine, and it is located opposite the impeller. On the other hand, the force exerted by the impeller causes fluid to flow into the turbine, and the latter begins to rotate as the fluid touches its blades.

It is worthy to note that this fluid is moved from the outer part of the turbine to its inner part repeatedly before it is finally transferred to the impeller. This constant movement of fluid from the impeller to the turbine and back to the impeller helps to create a fluid coupling. Also, the cycle of spins between the impeller and turbine helps to create torque.

However, the fluid flows in the opposite direction compared to when it was transferred from the impeller. As a result, this brings about the need for the direction to be reversed and that can be made possible using the stator.

3. Stator

A stator is a set of blades that are located between the turbines on the transmission shaft. The stator blades are positioned at angles that will enable a fluid’s direction to be reversed once it flows through it, and then be resent to the impeller.

A reversal in direction will slow down the fluid while increasing its torque. Also, when the car halts, the one-way clutch of the stator allows it to stop spinning, which stops the hydrodynamic circuit.

Root Cause of a Blown Transmission

A blown transmission can largely be attributed to torque converter problems which should not come as a surprise given how important this unit is in your car. The good thing is, getting a replacement for your torque converter is quite easy even though the bone of contention is being able to spot where the problem is emanating from.

Nonetheless, this should not be something to worry about since the outlined below will give you an idea of the potential issues in your car that can cause your transmission to blow up, leading to expensive repairs. Some of these signs that you need your transmission checked include:

1. Overheating

Overheating is never a good thing for your car since it is the first obvious sign that the transmission fluid is low and torque converter problems. That being the case, it can cause the torque converter to overheat and prevent it from transferring torque from the engine to the car’s transmission.

You’ll know it’s the effect is gradually taking a toll when you experience poor acceleration. On the long run, overheating of the torque converter can lead to a degradation of the transmission.

2. Shaking and Shuddering

Your car is meant to move smoothly and swiftly; however, if it begins to shake and shudder, it calls for serious attention. You can quickly tell when you’re driving on a smooth road, and it still feels like you are stepping on small bumps.

What could be the problem at this point? The shaking and shuddering could be as a malfunctioning in the lockup clutch. That being the case, you need to check that your lockup clutch is not worn out to eliminate any difficulties in moving from acceleration to direct drive.

3. Slipping

Another torque converter problem that could affect your seamless driving is its damaged fin or bearing. Slipping can also be as a result of too much or insufficient fluid in your transmission.

When this happens, there could be delays in transmission shifting it the transmission could slip in and out of gears. These problems can mostly be linked to the inability of the engine torque to be converted efficiently to hydraulic pressure required to shift gears within the transmission.

Conclusion

Advancements in technologies may have led to new features in automatic transmissions; nonetheless, the torque converter has always been an active part of these cars to enable the transfer of torque. That is why a car problem you’re experiencing now, especially a failure in your transmission can be pinned on the converter.

Possible signs such as overheating, shaking, slippage, among others is a dead giveaway that your converter needs to be checked. Consequently, it’ll save you the time, effort, and money, of trying to discover what the issue could be while you spend more time trying to resolve it in the best possible way.

The advent of several transmissions since the launch of automobiles means there are a whole lot of them in 2019 and many more can be expected in years to come. However, some like the Mopar 727, which is known for its strength and easy adaptability in just about any car makes it essential to understand how to identify Mopar 727 performance transmissions. It is needful given the many characteristics and advantages that can still be derived from using a transmission that is three decades old.

The Mopar 727 is also an excellent transmission to install into your Chrysler, AMC, or GM car or truck; thus, it can serve Chrysler and non-Chrysler applications. That being the case, we’ve outlined the unique physical and operational features of the Mopar 727, which will enable you to differentiate it from a wide range of transmissions that are also contending for attention.

What Is the Mopar 727 Performance Transmission?

The Chrysler A-727 transmission, also known as the TorqueFlite 8 units is a three-speed transmission that was launched around 1956. It was mainly used in Mopar cars with larger engine size from 1962 and also found a use case in certain vehicles as their original equipment component.

The A-727 transmission is robust and highly adaptable in several applications which can be attributed to its widespread use in about 30 years. Its strength meant it could be used in Chrysler cars and non-Mopar applications such as work trucks as well as high-performance vehicles like sports cars.

Within these vehicles, the Mopar 727 could handle engines whose horsepower went as high as 450hp which was an attestation of its strength. It can also work well in higher torque or higher rpm, and most notably, cars in which a bulletproof automatic transmission is required.

To that effect, if you decide to use this transmission today, then it will begin with knowing how to identify a Mopar 727 performance transmission.

Easy Ways to Identify 727 Performance Transmissions

Upon the launch of the earliest version of the A-727 in 1956, it featured a cast-iron case. However, from 1962, there was a switch to the use of aluminum cases. Thus, you’ll find one of the latest A-727 transmission using an aluminum case just like the Mopar vehicles between 1962 to the late 1980s. The A-727 is also unique from its oddly shaped oil pan with 14 bolts.

Other features that will enable you to identify the Moper 727 performance transmission are:

1. Transmission Bands and Shift Ratios

There are two transmission bands on the A-727 where one band serves for reverse and the other for kick down. This transmission’s shift ratios were:

• • First gear: 2.54:1
  • Second gear: 1.45:1
  • Third gear: 1.0:1
  • Reverse gear: 2.21:1

2. Adoption

A lookout for when the release year of the Mopar vehicle can help you ascertain if it is using an A-727 transmission or not. For instance, Mopar vehicles between 1962 and the late 1980s began to use the aluminum-cased A-727. The aluminum-cased A-727 was adopted in performance vehicles from other manufacturers from the mid-1960s. Similarly, the Jensen Interceptor and its Chrysler 383 engine took advantage of the Torque Command “8” which was released in 1956 as its automatic transmission.

3. Bell Housing

Depending on the engine you want to install the A-727 transmission in, it is needful to get one whose dimension or bell housing is right for your vehicle. An 18-inch bell-housing bolt pattern was used by small-block V-8s while an 18.875-inch bolt pattern was used by Chevrolet big-block applications. The AMC V-8 engines were drilled to the right small-block bell housing bolt pattern, and their rear output shaft can be a perfect fit to existing Jeep transfer case assemblies.

4. Transmission Upgrades

There were several upgrades to the A-727s which makes it needful to select the correct year of the donor car whose transmission you’ll be installing in your vehicle. That being the case, A-727s were push button shift whose push buttons were located on the dash from 1962 to 1964.

Few units from 1965 were still cable activated, but a majority of transmissions from 1965 and newer ones have a rod-style shift linkage. Between 1962 to 1965, transmissions featured a rear flange instead of a yoke linked to the driveshaft with a universal joint. Transmissions from years above this range featured a standard splined shaft using a basic slip yoke and cross-type U-joints.

5. Flexplate

Minor changes were still made to the A-727 after 1966, and one of such was the modification in flexplates in 1968 as well as the inclusion of a lockup converter in 1978. It is, therefore, important to select the right flexplate since those from 1968 and after came with flexplates with a larger center hole compared to those before 1968. In the same vein, a torque converter from 1966 and years after that, will not interchange into torque converters from years before 1966.

6. Year

An A-727 can also be identified as being a 1978 and newer lockup units just by examining the transmission’s input shaft. It was built with a lockup if the shaft is smooth at its last half inch, on the contrary, if it is splined to the end of the input shaft, then it is a non-lockup transmission. Pre-lockup converters before 1978 are also weighted as A, B, and C weights, and there’s no need to interchange either of these when trying to select the correct torque converter.

Conclusion

After taking a look at the easy ways to identify a Mopar 727 performance transmission, choosing the right one to install in your vehicle becomes a breeze. The A-727 is worth it when consideration is given to the fact that it’s been over 30 years since its first release; however, it can still offer strength and support high-performance power.

Whether its a replacement you’re looking for your Chrysler, AMC, or GM car, the A-727 is easy to find. All it’ll take is to tell it apart from a wide range of transmissions in the market using the specifications we have outlined above.

What’s more, selecting an A-727 that is right for the application it will be used in, takes it the extra step to ensure the level of performance you get is an impressive one. Thus, it is entirely up to you to make a choice from several depending on the year they were made whether they are older or newer versions of the Mopar A-727.

Ford’s C4 and C6 3 speed automatic transmissions are similar in operational characteristics; however, there are still unique differences between the C4 and C6 transmissions. Starting from the year they were produced, their specifications, as well as their applications, these two transmissions are worth comparing side by side.

For instance, while C4 transmissions may have been launched and further designed in different versions between 1964 and 1981, C6 transmissions found application in certain vehicles around 1966 to 1996. The list goes on and on, but there are also similarities between these two and the most obvious is that they are automatic transmissions that change gears automatically unlike manuals.

Nonetheless, let’s take a closer look at the differences between Ford C4 and C6 transmissions.

Differences Between Ford C4 and C6 Transmissions

The Ford C4 and C6 transmission specs show that there are apparent differences between either of these. The peculiar disparity between both include:

• • Year of production
  • Weight
  • Internal components
  • Evolved versions
  • Fluid type

1. Year of Production

The Ford C4 is also called the Dual-Range Cruise-O-Matic, FMX transmission and it was produced around 1964 and was used until 1981. Specifically, the vehicles that came with a C4 transmission were the Ford Bronco between 1973 to 1977, and the Ford F-series between 1965 to 1981. Here’s what it looks like:

• • Ford Bronco (1973–1977)
  • Ford Cortina (1974–1982 )
  • Ford F-Series (1965–1983)
  • Ford Fairlane (1964–1970)
  • Ford Fairmont (1978–1983)
  • Ford Falcon (1965–1970)
  • Ford Granada (1975–1982)
  • Ford LTD (1975–1980)

The C6 automatic transmission, on the contrary, was launched by Ford around 1966 and it found use cases until 1996. It was produced at Ford’s Livonia Transmission Plant, Michigan and in the mid-1980s, its production was transferred to a Sharonville Transmission Plant, Ohio.

Also, the C6 transmission was used in high-performance vehicles as well as trucks with more significant engines such as Ford trucks, passenger cars, and Lincoln cars. The C6 was evident in the Ford F-Series between 1967 to 1996 as well as the Ford Bronco between 1978 to 1991. In the latter version, five bell housings were used, and these are:

• • Diesel bell housing.
  • FE bell housing for the Ford FE family engines.
  • The Cleveland bell housing in the 351M, 400, and Ford 385 engine family.
  • Windsor bell housing for all Windsor engines, 300 “Big Six” I-6, and the 351 Cleveland.
  • Mel 462 used in 1966 to 1968 462 V-8 Lincoln Continental as well as 1968 to 1970 460 V-8 Lincoln Continental.

2. Weight

Ford C4 is a medium-duty transmission judging from its lightweight of 130 lbs dry w/ torque converter and its design with an aluminum case. So, if you’re wondering how heavy is a C4 transmission, then it does not pack so much load at all.

On the other hand, C6 transmission is a heavy-duty transmission that can handle much load. Like its predecessor, it featured a lightweight at 175 lbs dry w/ converter and an aluminum case. It is believed that by today’s standards, a transmission of this nature has a high-level parasitic loss as a result of its weight and size.

3. Internal Components

The C4 can be split into three sections, which are the transmission case, bell housing, and the tail housing.

On the other hand, the C6 identification is the Borg-Warner flexible shift band and the Simpson planetary gearset it features. Within its case are a one-piece casting and a bell housing.

Upon the C6’s launch, it featured 17.4 inches, 7 inches, and 14 inches tailshaft housing lengths for the Lincoln cars, Ford trucks, and Ford passenger cars, respectively.

4. Evolving

A look back at the C4 and C6 transmissions when they were launched shows that there have been other variants since then. An instance is the case of the C4, which featured a 0.788 inch, 24 spline input shaft between 1964 to 1969.

However, upgrades to the C4 in 1979 brought about a 26 spline, 0.839-inch shaft. The same was evident in 1971 when the input shaft was updated to feature 24 splines at the clutch hub and 26 splines on the torque converter side.

5. Fluid Type

Transmission fluid is essential in a car to allow the components to move swiftly while at the same time, ensure there is no overheating or slippage. Accordingly, the kind of transmission fluid the C4 uses is the Type F automatic transmission fluid. In contrast, the transmission fluid supported by the C6 is the Type FA automatic transmission fluid.

6. Modern Use

The contemporary use of the C4 and C6 transmissions are for different purposes. While both are used by hot rod and drag racers enthusiasts, the C6 has gained favoritism when it comes to offroad driving. The C4 is not quite suitable for off-road since it cannot handle as much power as the C6 and as such, it was mostly used in cars and not trucks.

7. Gear Ratios

The C4 gear ratios are:

• • First Gear 46:1
  • Second Gear 46:1
  • Third Gear 00:1
  • Reverse Gear 20:1

The C6 Gear ratios are:

• • First 46:1
  • Second 46:1
  • Third 00:1
  • Reverse 00:1

Similarities Between the Ford C4 and C6 Transmission

While there is a significant disparity between the C4 and C6 transmission, it’s worth noting that there are slight similarities between both. Some of these include:

• • Transmission speed
  • Simplicity
  • Upgrades
  • Gearset
  • Aftermarket support

1. Transmission Speed

The C4 and C6 are both 3-speed automatic transmissions designed by Ford.

2. Simplicity

Both transmissions’ design spoke simplicity and durability. The C6, for instance, was admirable for its simplicity, strength, and reliability. It is even more durable than the C4, which makes it more expensive. As of today, it is still a popular choice for motorsports such as off-road and drag racing vehicles.

3. Upgrades

The C4 and C6 transmissions later had better versions of themselves and what was also noticeable between the duo is that they then featured an overdrive gear.

Thus, if you’re wondering if a C4 transmission has an overdrive, it most certainly does today. The overdriven gears were not present when they have launched as well as a lockup torque converters which are now evident in new transmission for boosting fuel economy.

Similarly, the response to questions like how many gears does a C6 transmission has, would be three. What this boils down to, is earlier versions of these transmissions are entirely different from their later iterations.

4. Gearset

The C4 and C6 transmission upon their launch both depended on a Simpson planetary gearset.

5. Aftermarket Support

Given that it has been decades since the launch of the C4 and C6, a car enthusiast can get excellent aftermarket support for both transmissions.What’s also worthy to note, is that they have been revised to handle torque better than their older versions.

How to Tell a C4 From a C6 Transmission

A closer inspection of the C4 and C6 shows a similarity in physical appearance. However, they can be told apart by considering the following:

• • Determine the number of bolts securing the transmission’s oil pan to the transmission itself. On the C4, there will be 11 bolts while on a C6, there will be 17.
  • Ascertain where the drain plug is situated at the transmission pan. If the plug is at the side of the transmission’s pan, it is the C6 but on the bottom means it’s a C4.
  • Determine where the speedometer driver gear is located. If it is on the driver’s side of the extension housing, it is the C6 but a C4, if it is at the rear of the transmission at the point, then driveshaft is connected to the transmission’s back.

Conclusion

Judging from the internal and external components, there are apparent differences between the C4 and C6 transmissions. These differences will enable you to tell a C4 from a C6 transmission despite their similar appearance. There have also been upgrades to either of these two in order to improve their level of performance from what they could offer as at when launched.

Nonetheless, in the present year and beyond, they’ll still be noteworthy as some of the most popular transmission ever designed by Ford Motors. Their performance also has led to the creation of modern automatic transmissions which car fanatics have come greatly to rely upon.