Tech | Transmission Upgrade
Tremec's new T-56 Magnum six-speed...
Tremec's new T-56 Magnum six-speed manual gearbox, shown here in a cutaway display, is a strong and slick-shifting way to gear up your classic Ford. As with the latest factory-installed gearboxes, even Reverse gear is synchronized.
One need not possess the mathematical skills of Einstein to grasp the obvious advantages of a six-speed gearbox over any old-school three- or four-speed box. With a deep overdrive in Sixth gear, those manly 3.91 or 4.11 axle ratios in your classic muscle-bound Ford will effectively be whittled down to a far more highway-friendly size for economical, low-wear touring. Meanwhile, on the way up, you've got a half-dozen nicely spaced gear ratios to assist in the engine's accelerative efforts.
Till now, the unchallenged king of our six-speed go-to list has been Tremec's faithful and familiar T-56, which was first found in the Dodge Viper and eventually found a Ford home in the '03/'04 supercharged Mustang Cobra. But a new kid in town is ascending to the throne: Tremec's T-56 Magnum, which is both notably stronger and more user-friendly than its predecessor when it comes to classic Ford transmission swaps.
The Magnum's sturdy six-speed...
The Magnum's sturdy six-speed gear-train-basically lifted from the company's TR-6060 as found in the current GT500-is housed in a T-56-style case that has been re-engineered for greater strength. Behind the main case is a Tremec TKO-style tailhousing with its reversible, rectangular die-cast shifter base providing two of the Magnum's three possible main shifter locations.
Directed squarely at the performance aftermarket, the T-56 Magnum stuffs a re-engineered and strengthened T-56 aluminum case full of the latest generation of gear-train internals from Tremec's TR-6060 transmission-the OEM-specific six-speed whose variants roll off the production line in such current heavy hitters as the Shelby GT500, Dodge Viper, Cadillac CTS-V, Camaro SS, and SRT-8 Challenger. The result of this technology cross-breeding is a conservatively rated 700-lb-ft torque capacity blessed with OEM-quality shift characteristics, all in a package intended to be adaptable to many retrofit applications. And yes, we said a 700-lb-ft torque capacity-roughly 60 percent higher than that of the original aftermarket T-56, which itself was hardly limp-wristed.
Part of the T-56 Magnum's application adaptability stems from multiple shifter positioning options on the tranny case itself, as well as from a wide range of Tremec's available shifter bases to suit most any custom installation, all as detailed in our photo captions and sidebar. More flexibility comes from the Magnum's provision for either mechanical or hydraulic clutch actuation, plus the choice of mechanical or electronic speedometer connection.
The original T-56 was a strong...
The original T-56 was a strong gearbox. The Magnum is much stronger, as illustrated by this comparison of countershafts. The drive gears on the Magnum countershaft (left) have a much wider face width and surface area than the regular T-56's, for greatly increased torque capacity at 700 lb-ft. The one-piece Magnum countershaft is also much more resistant to bending or distortion than is the two-piece T-56's, and has notably larger bearings for improved support. Not shown here, the main shaft is also of notably larger girth than that of the older T-56.
Another advantage shared with the "basic" T-56 is that the Magnum is not limited by an integral bellhousing. Instead, its mid-plate bulkhead design means it can be paired with whatever clutch housing is best suited to your project. Currently, the Magnum is available from Tremec paired with either a mod-motor or small-block (5.0L/5.8L) housing, but we've also seen various online outlets advertising matching big-block Ford bellhousings.
OK, we can see that you're ready to pull the trigger on a Magnum, but you still have one more choice to make, because it's available with two different gearsets. The wide-ratio variant has a 2.97:1 First gear mellowing out to a 0.50:1 Sixth. Fans of closer ratios can opt for a version with a 2.66:1 First gear and a 0.63:1 top gear. Full ratio specs are set out in our sidebar. Current retail is around $2,800, which is only about $600 more than the current TKO five-speed.
Tremec T-56 Magnum Shifters
|TUPC9633||Standard upright rear-shifter assembly||Original equipment replacement. Red anodized finish|
|TUPC9650||Standard upright mid-shifter assembly||Includes hardware, cover plate, and instructions|
|TUPC9655||2-inch offset rear-shifter assembly||Includes instructions, uses existing mounting hardware|
|TUPC9656||1-inch offset rear-shifter assembly ||Includes instructions, uses existing mounting hardware|
|TUPC9658||2-inch offset mid-shifter assembly||Includes hardware, cover plate and instructions|
|TUPC9659||1-inch offset mid-shifter assembly||Includes hardware, cover plate and instructions|
|TUPC9643||2-inch rear-shifter offset lever kit||Includes upper & lower levers, link w/hardware, and instructions|
|TUPC9443||1-inch rear-shifter offset lever kit||Includes upper & lower levers, link w/hardware, and instructions|
|TUPC9441||2-inch mid-shifter offset lever kit||Includes upper & lower levers, link w/hardware, and instructions|
|TUPC9442||1-inch mid-shifter offset lever kit||Includes upper & lower levers, link w/hardware, and instructions|
Tremec Magnum Transmission Fitment
|Part Number||Type||Drive Type||Shaft Spline|
Tremec Magnum Transmission Gear Ratios
Available Tremec Bellhousings
|TNCM1078||T-56 Magnum, Ford 4.6/5.4L w/Mechanical Clutch|
|TNCM1078||T-56 Magnum, Ford 4.6/5.4L w/Hydraulic Clutch|
|1386-212-004||T-56 Magnum, Ford 5.0/5.8L w/Mechanical Clutch|
|(Other engine applications can be found in the aftermarket)|
Room for the Magnum's wider,...
Room for the Magnum's wider, stronger gears comes partially from its slimmer synchronizer sliders (left), which also feature fine-pitch tooth angles to decrease the amount of travel for engagement-meaning shorter shifts.
Shift effort is also reduced...
Shift effort is also reduced due, in part, to the synchronizer support system's new spring-loaded, ball-type inserts (arrow) which offer less friction than the hoop-style strut seen on the original T-56 slider at right. The Magnum also utilizes triple-cone synchronizers with a sintered-bronze lining on the 1-2 and 3-4 sliders (whereas the T-56's were dual-cone with carbon-paper lining), helping contribute to both its sophisticated shift quality and much higher torque capacity.
Shift forks are also revised...
Shift forks are also revised on the Magnum, with perhaps the most significant improvement being the cast-in shift links (Z-bars) in place of the separate links found on the original T-56 (right). As you can see, the old links slid into a keyway machined into the shift-rail bore, and it was this keyway that could lead to bending or deflection of either the shift rail or fork, causing shift glitches in the original T-56 during speed shifting. The shift pads on the Magnum forks are also enlarged for better control and longevity.
This comparison of Magnum...
This comparison of Magnum (left) and original T-56 input shafts highlights the Magnum's much larger bearing diameter and gear face width. What doesn't show clearly is the larger diameter of the Magnum's 26-spline shaft-no 10-spline input will be offered. The length of the input splines is also much greater on the Magnum in order to easily accommodate dual-disc clutch setups.
Thanks to a revised manufacturing...
Thanks to a revised manufacturing process, the clutch teeth on the Magnum's wider driven gears (left) are of a more intricate design than previous T-56 versions, having a finer pitch as well as machined-in positive stops. This not only contributes to shift quality but also virtually eliminates the possibility of over-thrown shifts.
The Magnum is very user-friendly...
The Magnum is very user-friendly when it comes to shifter location. On the tailhousing section, the elongated shifter base is reversible to one of two locations (this particular base is cutaway to show the available forward cup position on the shift rail). A third shifter location (called the mid-shift position) is accessible immediately forward of the tailhousing. All told, this provides more than 7.5 inches of fore/aft shifter wiggle room.
Yet more adaptability comes...
Yet more adaptability comes from available offset links, which as seen here, are rotatable through 360 degrees to position the shifter arm precisely where desired. This particular shifter base would be used in the mid-shift position.
A wide range of shifters are...
A wide range of shifters are available to help match a T-56 Magnum to your particular project (our sidebar sets out part numbers and descriptions.) Those with the rectangular bases shown here would be used on the transmission tailhousing, while the smaller square-based models would bolt to the forward "mid-shift" position. All have billet aluminum bases finished in Tremec's trademark red anodizing.
Tremec's short-throw shifters...
Tremec's short-throw shifters employ a unique "adjustable bias" design, having hex screws to allow custom-tailoring of shift lever lateral preload levels. The result, says Tremec, is dramatically enhanced shift accuracy that virtually eliminates 2-3 shift issues.
The offset links can be had...
The offset links can be had in either 1- or 2-inch lengths, and kits are available to convert standard upright shifters into offset units for a fraction of the cost of a new, complete shifter assembly.
As the T-56 Magnum is meant...
As the T-56 Magnum is meant to be compatible with as many applications as possible, a mechanical speedo pickup is provided on the left of the tailhousing, and an electronic pickup on the right, similar to the current TKO series of five-speeds. As mentioned, the input shaft has 26 splines, the output shaft, 31 splines.