When TREMEC and Modern Driveline introduced the TKO five-speed transmission with 500 and 600 lb/ft of torque capacity back in the 1990s, it introduced a new dimension in power capability to the Mustang and other period muscle cars. The TKO was a refreshing improvement over the TREMEC T-5 five-speed transmission. It could take a lot of abuse and come back for more.
Though the TKO has been a terrific high-performance transmission for a long time now, TREMEC knew it needed to develop a better version of this gearset in a package yielding better fitment, durability, and efficiency. TREMEC engineers spent pain-staking time and resources developing the all-new TKX. The TKX is an aftermarket-specific five-speed transmission, not an OEM box reinvented for the aftermarket. TREMEC engineers looked at what they liked about the TKO five-speed, what they didn’t like, and what they could do to make the TKO’s bones even better. They decided to first put the TKO’s gearset in a vastly improved case. In the end, they developed a new five-speed transmission offering better fit, higher torque capacity, and vastly improved durability.
The end result of all this research and development is the all-new TREMEC “TKX” transmission from Modern Driveline, which delivers smooth shifts at high rpm via multi-cone synchronizers and hybrid synchronizer rings. What’s more, noise, vibration, and harshness (NVH) issues have led to a better gearset engineered to control stress levels with structural stiffness in a new, ribbed main case and extension housing. Real durability is further enhanced with wider gear widths, gaskets at all joints, and caged needle bearings in all locations.
We’re impressed with the all-new space-saving, smooth shifting, tough-tested TREMEC TKX transmission from Modern Driveline. From the people who invented five-speed conversion kits for an American icon in the first place comes the new five-speed transmission Mustang enthusiasts have been waiting for.
As vehicle quiet has become more important, noise, vibration, and harshness (NVH) have become TREMEC’s focus. TREMEC engineers designed a ribbed, three-piece aluminum main case, intermediate plate, and extension housing for structural stiffness, which greatly contributed to reduced NVH. Their close attention to detail eliminated the potential for leaks as they perfected flange mating surfaces. Improved durability continues with oversized gear widths, which can now handle high-load shifts and there are caged needle bearings in all gear positions.
A ball detent is located on each shift rail to improve shift feel and provide precise, smooth shifting. Simulation software optimized the size and configuration of the chamfers in the gates and selector finger, so there’s no sticking between gates and shifting stays true in both normal and aggressive driving.
We’re impressed with the all-new space-saving, smooth shifting, tough-tested TREMEC TKX transmission from Modern Driveline. From the people who invented five-speed conversion kits for an American icon in the first place comes the new five-speed transmission Mustang enthusiasts have been waiting for. It is priced competitively, compared with the proven TKO, and what’s more, it will fit your Mustang regardless of generation.
The TKX is truly a better five-speed transmission with a streamlined case to fit any 1965-04 Mustang without transmission tunnel modifications. Here’s what you get for your Modern Driveline dollars:
There’s but one modification issue with the TKX with 1965-66 Mustangs only. The transmission support floor pan brace may have to be moved aft 2.5-inches for proper crossmember alignment with the transmission mount. Modern Driveline is currently working with a 1965 Mustang development mule to refine this swap. Production TKX units will become available by the time you read this.