MDL TREMEC GM TKX 5-Speed | 1968-1982 C3 Corvette | 2.87 First, 0.68 OD | 2” Left Side Shift Rear, Straight Up No Offset
Key Features
- 600 lb-ft torque capacity with 7,500 RPM shift capability and 8,000 RPM engine speed rating
- Gearing ratio (2.87, 1.89, 1.28, 1.00, 0.68) - deep overdrive drops highway RPM for improved cruising
- 26-spline input shaft (1-1/8 in. diameter) and 31-spline output shaft for added strength
- Compact end-loaded aluminum case fits most GM tunnels without floor modifications
- Ribbed 3-piece housing (main case, intermediate plate, rear extension) for structural stiffness
- Multi-cone synchronizers with sintered carbon/bronze hybrid rings for smooth high-RPM shifts
- ASTM 4615 special-grade steel gears and shafts with caged needle bearings in all gear positions
- GM Muncie bellhousing bolt pattern - direct swap for 3-speed and 4-speed applications
- GM 0.590-inch pilot tip with 1.375-inch OD throwout bearing guide tube
- Built-in reverse light switch and cruise control safety switch
- Dual speedometer outputs: mechanical 7-tooth Ford gear (adaptable to GM) plus OSS two-wire analog sensor
- 99 lbs dry weight; 2.7-quart fluid capacity
- High-performance short-throw billet aluminum shifter included
- MDL side shift modification with a straight up offset stub - precise shifter placement without compromise
- Shifter Stub Location: 2” left of center line, 19.52” back from the bellhousing face
- MDL Exclusive - not available through TREMEC
Description
C3 Corvette owners swapping from a factory four-speed face a frustrating tradeoff: modern five-speed performance usually means an awkward shifter location that doesn’t align with the original console cutout. MDL solved this problem with an exclusive modification that relocates the TKX shifter stub to the OE four-speed position — a solution not available through TREMEC.
This isn’t a bolt-on shifter or adapter plate. MDL carefully machines the transmission case and integrates new internal components to move the shift mechanism forward. The result is a close-ratio custom-made shifter that becomes an integral part of the transmission. Each unit is hand-prepared at MDL’s facility in Caldwell, Idaho to ensure quality and precision. Many hours of R&D went into developing this modification, and no upgraded TKX leaves unless it’s right.
The foundation is TREMEC’s proven TKX platform with 600 lb-ft torque capacity — ideal if you’re making over 400 horsepower and need an upgrade from your four-speed. All gears and shafts are made from special-grade ASTM 4615 steel for the increased demands of modern engines. The three-piece ribbed aluminum housing provides outstanding structural stiffness while the end-loaded design keeps the compact case within the C3’s tight tunnel. Tapered roller bearings on input, output, and countershafts improve performance and reduce noise, while caged needle bearings on the mainshaft optimize durability. The single-piece countershaft provides increased torque carrying capacity, and the rear mainshaft support bushing is moved closer to the gearbox for better support.
This TKX uses the GM TKO bolt pattern with a 7.2-inch input shaft, 0.590-inch pilot tip, and 1.375-inch OD throwout bearing guide tube. Short input shaft options allow it to bolt to GM close-pattern three or four-speed bellhousings. Built-in electronics include an OSS two-wire analog speedometer sensor, reverse light switch on the left side, and cruise control safety switch on the right. Fluid capacity is 2.7 quarts using TREMEC HP-MTF, GM Synchromesh, Amsoil ATF, Mobil 1 Synthetic ATF, or Dexron III. All mating surfaces are sealed with gaskets for leak-free operation.
Kit Includes
- TREMEC TKX 5-speed transmission (TCET17805) with 2.87/1.89/1.28/1.00/0.68 gear ratios
- High-performance short-throw billet aluminum shifter (2” left side shift front, straight up no offset stub)
- Gaskets for all mating surfaces
- Built-in reverse light switch (left side)
- Built-in cruise control safety switch (right side)
- Mechanical speedometer drive gear (7-tooth Ford pattern, adaptable to GM)
- OSS two-wire analog speedometer sensor
- MDL extended warranty: manufacturer warranty plus 1 additional year with 1-year grace period
- Lifetime technical support