What You Need to Know Before Swapping a TR6060 Gearbox

In Summary

  • The TR6060 replaced the T56 in 2008 and is the stronger of the two, with wider two-piece gears, a single-piece countershaft and triple-cone synchros on the lower gears, rated between 430 and 650 lb-ft depending on the gearing inside it.
  • Gear ratios vary widely between donor cars, so an HSV box and a Corvette box will make the same car feel completely different before you touch the diff.
  • Most of the work in a TR6060 swap sits around the gearbox rather than in it, in the shifter position, the tailshaft flange, the speedo signal and the clutch hydraulics.

How Does the TR6060 Differ From a T56?

TREMEC replaced the T56 with the TR6060 for the 2008 model year. The architecture stayed familiar, with six forward gears, a double overdrive layout and aluminium alloy used for the main case, extension housing and clutch housing. Almost everything inside was strengthened.

The TR6060 runs wider two-piece gears with machined clutch teeth, a single-piece countershaft, triple-cone synchros on the lower gears and double-cone synchros elsewhere, including a fully synchronised reverse. The shift forks carry removable wear pads.

The result is a gearbox that shifts more easily, holds more torque and tolerates abuse better than the T56 it replaced. That is why so many Australian builds go looking for one.

For components used in TR6060 and T56 conversions, see the TR6060 and T56 shifter relocation range from Malex Motorsports.

Which Gear Ratios Will You Get?

This is the part builders skip, and it decides how the car drives.

An HSV E Series or Gen-F box runs 3.01, 2.07, 1.43, 1.00, 0.84 and 0.57, the same set fitted to the 2010 to 2015 Camaro SS. A C6 Corvette box runs 2.66, 1.78, 1.30, 1.00, 0.74 and 0.50, which gives a much taller first gear and a far longer sixth.

Both work. The HSV set suits a heavy street car with a moderate diff ratio, while the Corvette set suits highway cruising and a shorter diff behind it. Work the ratios out alongside your diff and tyre diameter before you buy, because changing them afterwards is expensive.

How Much Torque Will It Actually Hold?

TREMEC rates the TR6060 between 430 and 650 lb-ft, roughly 580 to 880Nm, depending on the gearing in the box. There is no single number that covers every version.

The boxes fitted behind the larger GM V8s sit at the upper end of that range and will handle a healthy cammed LS without complaint. Add boost and sticky tyres and the picture changes. Plenty of Australian builds have run a TR6060 well past 700 horsepower at the wheels, and the usual warning signs are gear whine and a reluctant third gear under hard acceleration.

If the combination is heading a long way past the rating, budget for an upgraded gear set or a T56 Magnum from the start.

What Goes Wrong With a TR6060?

Worn synchros are the common complaint, felt as a crunch into second or third on a quick change.

Shift fork wear is the other one. The removable wear pads make the TR6060 more serviceable than the T56, though the pads still wear, and the symptom is vague engagement and the occasional missed gear.

The concentric slave cylinder deserves its own thought. It sits inside the bellhousing, so replacing one means pulling the gearbox back out. Fit a fresh unit whenever the box is already out.

When you are inspecting a used box, judge it on shift feel, noise in every gear and the condition of the input shaft splines rather than the kilometres on the paperwork.

What Does the Swap Actually Involve?

Bolting the gearbox to an LS is the easy part. The work sits around it.

The TR6060 is long and wide, so most older Australian chassis need tunnel work and a new gearbox crossmember. The input shaft is 26 spline, which means a matching clutch disc, and the hydraulic release bearing lives inside the bellhousing, so the crush between the bearing and the pressure plate has to be measured and shimmed before the box goes in for the last time.

The factory VE and VF gearbox uses a bolt-on output flange in place of a slip yoke, so a 1350 tailshaft flange adaptor is needed to run a conventional 1350 yoke.

There is no mechanical speedo drive either. The box sends an electronic signal, so a cable-driven speedo needs a conversion to read correctly. Reverse lights and the reverse lockout also need wiring in.

For applications that need both shifter relocation and the 1350 flange adaptor, Malex also offers a 770mm TR6060 shifter and 1350 universal joint adaptor kit.

Why Does the Shifter Position Matter So Much?

The shifter catches more people than anything else on this list. The factory VE and VF TR6060 uses an external remote linkage that places the lever well back over the tailshaft, which is correct in a VE Commodore and wrong in almost everything else.

Drop that box into a Torana, an HQ, an early Falcon or a VB to VL Commodore and the lever lands behind the seat or through the wrong section of tunnel. Cutting the floor to suit is the expensive way out of it.

A shifter relocation kit replaces the factory remote linkage with a direct mechanism that brings the lever forward to roughly where the original shifter sat. Malex designs and manufactures its TR6060 shifter relocation kits in Australia and offers them in several lengths, so the lever can be placed where the driver expects to find it.

For VL, VN, VG, VP, VR and VS applications, the 770mm TR6060/T56 shifter relocation kit is designed for these applications. For earlier VB to VK Commodores, Toranas and other retro conversions, the Malex retro swap shifter kit provides a different mounting position.

Sort the shifter, the flange and the speedo early and the rest of a TR6060 swap comes down to measurement and patience. Talk to the team at Malex Motorsports about your chassis before you commit to a box.

FAQ

Yes. The TR6060 fitted to GM applications uses an integral aluminium clutch housing that bolts to the standard LS bellhousing pattern. You still need the correct flywheel, a 26 spline clutch disc and the right hydraulic release bearing setup.
It is. The TR6060 uses wider two-piece gears, a single-piece countershaft and improved synchronisers, and TREMEC rates it between 430 and 650 lb-ft depending on the gearing. It also shifts more easily than the box it replaced.
The VE and VF HSV boxes are the most common here and carry the 3.01 first gear set, which suits a heavy street car. Corvette and later Camaro boxes run taller ratios and pair better with a shorter diff. Choose on the ratios rather than on availability alone.
Usually not without work. The TR6060 is longer than most gearboxes it replaces, so the tailshaft normally needs shortening and rebalancing, and the factory VE and VF output flange needs an adapter to run a conventional 1350 yoke.
In a VE or VF, no. In almost any older chassis, yes. The factory remote linkage puts the lever a long way back, so a relocation kit is the straightforward way to get the shifter into the right position without cutting the floor about.

Glossary

TR6060: The six-speed manual TREMEC introduced in 2008 to replace the T56, fitted to HSV E Series and Gen-F, Camaro SS, C6 Corvette, Cadillac CTS-V, FG Falcon, Dodge Viper and others.

T56 Magnum: TREMEC’s aftermarket version of the same design, sold as a complete unit for swaps and offered with a choice of shifter positions and speedo drive options.

Double overdrive: A gearbox with two ratios above 1.00 to 1, in this case fifth and sixth, giving relaxed highway cruising behind a short diff ratio.

Synchroniser: The cone-shaped clutch inside the gearbox that matches gear speed during a change. Triple-cone units on the lower gears give the TR6060 its lighter shift.

Shift fork: The component that slides the synchro hub into engagement. TR6060 forks use removable wear pads, which are a service item rather than a whole fork replacement.

Concentric slave cylinder: The hydraulic clutch release bearing mounted around the input shaft inside the bellhousing. Its crush against the pressure plate must be set before assembly.

Remote shifter linkage: The external lever arrangement fitted to VE and VF gearboxes that moves the shifter position rearwards over the tailshaft.

Shifter relocation kit: A replacement mechanism that moves the lever forward from the factory remote position to suit an older chassis, avoiding major floor modification. See the Malex Motorsports shifter relocation range for TR6060 and T56 applications.

Output flange: The bolt-on tailshaft mounting used on factory VE and VF boxes in place of a slip yoke. An adapter converts it to a conventional 1350 yoke.

Crush: The preload between the hydraulic release bearing and the clutch pressure plate fingers, set with shims and checked before the gearbox is fitted for the final time.

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