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The Best Mopar Transmissions Of All Time
Here is our list of the most excellent transmissions produced under the Mopar family.
TorqueFlite Automatic A-727
The Chrysler TorqueFlite A-727 has to be one of the finest automatic transmissions ever built. This transmission backed up some of the most iconic muscle cars of the 60s and 70s, including the 1962 Candymatics, Dick Landy’s ‘68 Dodgene , and many others. The 727 was considered reliable, indestructible, and easier to work on. Even today, it is a preferred transmission for drag strips and off-road racers.
The key to the 727 lay in the fact that it wasn’t complicated, with three simple forward gears and a parking lock pawl so that the car would not roll after being shifted into Park. Every version of the TorqueFlite A727 had the same gear ratios (which are listed below). With two transmission bands, the 727 used an essential Simpson planetary gear set with a free-wheeling clutch, adding to its durability. (The A727 was one of the first transmissions to use these heavy-duty clutch parts, both Ford and Chevy would eventually use similar systems to design the C6 and TH400 automatics)
The A727 had an aluminum case (unlike the A466’s cast iron), which reduced the weight, and made the car faster for the strip. Another consideration was that the tranny would bolt to almost any crankshaft Mopar made, which meant that it could be swapped between vehicles easily. Again, an advantage for a racing application where mechanics often have strict time guidelines to get cars ready to race.
When the TorqueFlite first came out, it was operated as a push-button transmission. After a couple of years, Mopar shifted away from the push-to-shift mechanism to cable and then to direct linkage. Over the years, the transmission received updates and some modifications, but the basic internals that made the A727 what it is stayed true for almost three decades.
Mopar produced the TorqueFlite into the nineties when it made its last appearance in the Jeep Grand Wagoneer. The transmission didn’t just appear in drag racing. It was a mainstay of Dodge, Chrysler, and Plymouth cars for nearly 30 years, appearing in everything from sedans to muscle cars to pickup trucks.
Chrysler A-833
Chrysler’s attempt to back the new 426 Hemi engines with a Borg Warner’s T-10 transmission failed miserably, and it soon became apparent that something had to be done. (Mopar continued to offer the BW T-10 for a couple of years on V8s with smaller displacements, but it was a poorly built transmission with a bad design). Mopar needed a four-speed manual that was durable and strong, that could handle the loads that larger V8s were producing. To rectify this problem, Mopar turned to New Process, and the Chrysler A-833 was born. It found its way into plenty of Mopar A - B - C and E models, as well as plenty of race cars, most notably the 1970 Ronnie Sox’s Plymouth Hemi ‘Cuda, which might be one reason he was nicknamed “Mr. Four-Speed.”
The A833 was a heavy transmission with a cast iron case, but NP built it this way intentionally to provide added strength and durability. For the first year of production, the A-833 had a ball and trunion setup to connect with the driveshaft, but this was modified to the more efficient spline output that accepted a slip-yoke. Over the years, the A-833 was manufactured with various spline counts and shaft lengths depending on the type of engine they were to be used for.
The most significant change to the A-833 occurred in 1975 when the transmission received an aluminum case and added overdrive (the third gear was reduced to .73:1 so that it could be used for cruising, and the fourth gear became the new third gear). The changes increased the A833’s usage, as fuel economy became a concern for manufacturers and the shell-shocked buying public (having just gone through an oil embargo). Mopar used the transmission over a broad section of its cars and for Dodge trucks and both Dodge/Plymouth cars and vans.
The transmission was so popular that GM used a version of it in some of their two-wheel and four-wheel drive pickups and Suburbans. Eventually, the A833 was phased out in the mid-eighties.
Borg Warner T56
If you develop a high-speed sports car, like the one in the V10 Viper, it stands to reason that you might want to think about creating a transmission capable enough of handling the punishment that the motor is likely to inflict. That was the quandary that Chrysler faced in the late 80s. They had developed the Viper with an engine powerful enough to push 198 mph but didn’t have a manual transmission to back it up.
Enter the BW T56. First developed to support the load of a monstrous V10, the transmission was soon adopted for use in Camaros and Corvettes, and the Ford Cobra. Dodge used the T-56 in its Ram SRT10 and Dodge Vipers until the Tremec TR-6060 replaced it. Many of the transmissions that are in use today, including the new Dodge Challenger SRT Demon 170 and the current Dodge Viper, are based on the T-56.
The T56 is a six-speed manual with a hydraulic clutch assembly (other than the Cobra) housed in an all-aluminum casing. The aluminum case was a key to the strength of the transmission (it could hold the robust internals) and was light enough to find use in various high-performance vehicles.
Early versions used a 30-spline output shaft to handle the 550 lb-ft of torque the Viper put out (Chevy used a 32-spline in their short-lived SSR). The transmission used internal stops rather than stop bolts inside the shifter mechanism. The T56 was designed with a two-piece counter shaft, where the main shaft housed gears 1 - 4 and an auxiliary shaft with 5th and 6th gears and reverse spliced into the main. Two overdrive gears and stainless steel synchros (the GM and Ford versions used brass) helped give the T56 an advantage in boosting fuel economy, which tended to surprise both owners and reviewers alike.
In the late 90s, BW sold the transmission to Tremec who continued to produce it. The trouble with the T56 is that it had limits, and when Dodge reintroduced the Challenger in 2008 with only an automatic transmission, the T-56 just didn’t fit in with the future plans it wanted to take the vehicle. So, Tremec came to the rescue (it had already been working on the T-56’s replacement). It was decided that the new 2009 Dodge Challenger SRT8 and R/T should get an optional Tremec 6060 six-speed manual introduced on the Viper the previous year.
Tremec TR-6060
While the Tremec 6060 has a lot to do with the T56, there isn’t any question that it's still a very good transmission currently used in various Dodge, Chevrolet, and Cadillac vehicles. (Not to mention its use in many other cars over the years, like the 2009 - 13 Corvette, the ‘08 - 16 Ford Falcon, 2010 - 14 Ford Shelby GT500, just to name a few).
While the 6060 does resemble the T56, there are some differences that are important to note. The 6060 has a higher torque capacity, which helps it handle the stress of the higher-powered engines that Dodge seems to have loved so much (at least until this year). The increased torque ability means better initial acceleration, which as any drag racer will tell you, is where races are won or lost. In addition, the Tremec has a wider gear ratio, which improves the car’s ability to accelerate and reach massive top speeds without burning up.
The 6060 is a double overdrive transmission with six forward gears and a reverse. Tremec discovered that by making the gear train wider and the synchronizers narrower, they could increase the torque capacity of the transmission and provide smoother shifting at higher rpms, while at the same time keeping the internals small enough to fit into a transmission case that wasn’t any bigger than the T56 had been.
Other improvements were the use of aluminum on the clutch case and extension housing as well as the main casing, further lighting the transmission. The use of a single-piece counter shaft provided durability. The increase of the synchromesh where the ring diameter with the first and second gears uses a triple cone, while gears 3, 4, 5, and 6 receive double cone treatment helping reduce shift travel. The reduction is shift travel allowed for larger internals which only added to the transmission's integrity and increased torque capacity even more.
ZF 8HP90 8-speed
How could we ignore the transmission that will finish the illustrious run of Hemi engines as we know them? The ZF 8HP70 (Dodge Charger) and the 8HP90 (Challenger) have a reputation for being excellent transmissions because the new Demon 170 is putting out around 945 bl-ft of torque.
The advantage of this eight-speed automatic transmission is its versatility. It is compatible with a wide variety of rear-wheel drive vehicles and can be used in four-wheel drive and all-wheel drive applications. Most luxury models use some form of the ZF gearbox, including Aston Martin, Dodge, Chevrolet, Ford, Alpha Romeo, and BMW (along with many others).
The emphasis of the ZF transmissions is not to increase power ratios but improve fuel efficiency. By reducing the transmission weight and increasing the internal components' flexibility, the designers struck the mother lode of how to build a transmission that is as home in a Jaguar as it is in a Ford F150 or Dodge Durango.
The ZF 8 speed uses multiple planetary gear sets with five shift elements, two brakes, and a trio of clutch packs. ZF created these internals to be more efficient. Since only three of the five shift elements are used in any one gear, the internals waste less energy in producing the necessary rpms for the engine's demands.
ZF didn’t stop with just redesigning the main part of the transmission, it changed the way the torque converter works. By using flexible lock-up clutches and a twin-torsional damper to minimize vibrations and allow the transmission to select gears earlier (reducing shift lag) and thereby helping with both fuel economy and efficiency.
