TREMEC T56 and Magnum Transmissions

Pop Quiz: The difference between a T-56 and a Magnum 6-Speed


1. What was the T-56 originally designed for?

The T-56 was designed by Borg/Warner and GM for the Dodge Viper and then utilized across GM in several other platforms. TREMEC acquired Borg-Warner in December 1996 and continued to produce the transmission for the Big 3 and even a few other automakers. These transmissions vary slightly, as each was tailored specifically for each OE application. In 2007, the T-56 was replaced by the TR-6060 which debuted in the Ford Shelby GT500 in 2007.

2. When did TREMEC start producing Magnums?

TREMEC took note of the classic car market swapping out their old 4-speeds not only with the popular TREMEC TKO, but also with T-56 and TR6060's found at junkyards. The demand was there, so a new transmission was designed specifically for the aftermarket. When TREMEC released the Magnum in 2009, they used the name "T-56 Magnum" because they wanted to "let customers know the trans was not some brand-new, unproven design; the name Magnum signified that this new unit was indeed something special – unique from all T-56 transmissions that came before it."[1]

The name ended up confusing large portions of the market. Not only did people confuse the names, but they didn't realize the Magnum had more in common with the TR-6060 than the T-56. Eventually, TREMEC dropped the "T-56" from the Magnum all together hoping to help clear up the misunderstanding.

3. What are some of the differences between the T-56 and the Magnum?

• Shifter locations - The Magnum comes with 2 stock shifter locations (3 with a front shift kit) and the T-56 comes with one (2 with a front shift kit). Also, the one location on a T-56 will vary depending on which OE application it was originally in. This means the Magnum is much easier to swap in to a wider range of applications, which is exactly what it was designed to do.

• The Magnum has dual (electronic and mechanical) speedometer pickups

• The Magnum has greater torque capacity thanks to substantually different internals. The gears, syncrhonizers, input shaft and clutch forks were all redesigned.  

4. Does SST support or make kits for the T-56?

Our PerfectFit™ and RestoFit™ Kits are designed around the TREMEC Magnum. They do not work with the T-56 because the tailhousings are different between each T-56 model and the T-56 has a skip-shift solenoid protuding from the case. This effects everything from our crossmember, cutting templates, sheet metal, and other components we designed specifically for the TREMEC Magnum.

Additionally, the gears, syncrhonizers, shift forks and other internal components of the T56 are completely different from the Magnum and as pointed out earlier, vary between each application the T56 was used in. We do not carry these parts and we do not repair T56 transmissions or provide warranty repairs to these or the TR-6060 transmissions.

We DO offer a front shift kit for the TREMEC T56, so if you already have the T56 and need the shifter further forward, we have them packed up and ready to ship in our webstore!

If you'd like to learn more about the differences between the transmissions TREMEC offers, they have even more information in their blog.


  1. "The Differences Between the TREMEC T-56 and Magnum 6-Speed". Retrieved September 1, 2017.