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HVDA 5 Speed Conversions

Reduce noise and lower top-end cruising revs by as much as 22 percent when converting your Triumph to a 5-speed transmission. With the HVDA 5-speed conversion kits, bolting on a reliable, fully synchronized, Toyota 5-speed transmission is easy! Overdrive transmissions were rare before freeway driving was common. Today, we find ourselves spending a lot of time on the freeway, and without overdrive, your engine has to work a lot harder at these speeds. The HVDA kits resolve this issue, and fit all TR-2 through TR-6 engines by utilizing the following 5-speed gearboxes:

  • -Toyota 1982-85 Celica or Supra
  • -Toyota 1984-96 Pickup Truck
  • -Lexus 1992-97 SC300

Smoother shifts combined with a shorter throw make the ease of shifting, especially downshifting, one of the biggest advantages over stock. Compared to a Triumph gearbox with an A-type overdrive, the full conversion weighs 50 lbs less and doesn't leak like one either! The conversion was also designed in a way to retain the stock shift-lever location that allows you to keep your interior looking original!


Another great advantage of installing this 5-speed conversion kit is that it requires no cutting, drilling, or welding. If you know how to remove and install a transmission and clutch, you're qualified to do this job. No special tools are required.



The HVDA Triumph Transmission Conversion Kit contains the following components to make the conversion:

  • -Custom bell housing that adapts the Toyota transmission to your engine
  • -Gear shift lever adapter mechanism and housing
  • -Speedometer cable and mounting bracket
  • -Transmission output flange/slip yoke and a locking collar for the driveshaft
  • -Transmission mounts and brackets for your specific model of Triumph
  • -Clutch disk and alignment tool
  • -Pilot bushing and sleeve
  • -Hydraulic clutch release throw out bearing with steel braided hoses



  • -Toyota/Lexus 5-speed transmission NOT included.
  • -Refer to the "Instructions & Resources" tab for additional info on inspecting and sourcing a transmission.
  • -Pressure plate NOT included. All cars, TR2-TR6, require the TR6 pressure plate. Moss part # 593-010, TR6 pressure plate, has been tested and known to work well with this conversion. The older coil-spring style pressure plates are not compatible with HVDA kits.
  • -If you have a W58 transmissions with a remote mounted shifter that hangs off the rear of the transmission, such as one on the Lexus SC300, you will need to replace the shift lever housing (Toyota # 33502-14100), which can be very difficult to source. However, Moss has developed an alternative that can be used. See Shift Lever Housing by HVDA.
  • -Some 4-cylinder cars may require driveshaft modifications. See instructions for addition info.
  • -The conversion is straightforward, but just in case you are hesitant, we recommend professional installation.



The Longest in the Business

  • All Classic British products are warrantied to be free from defects in material and workmanship for 2 years from the date of invoice.
  • All superchargers, supercharger components, and supercharger hardware are warranted to be free from defects in material and workmanship for 1 year from date of invoice.
  • Moss Motors, Ltd. will, at its discretion, repair or replace any part that fails in service within the warranty period. This warranty does not cover labor, failure of related components, normal wear of brake or clutch components or failure resulting from alteration, misuse, accidental damage, faulty installation, or faulty repair.
  • Warranty requests should be submitted to our sales department and must be supported by the original Moss Motors purchase invoice and documentation of the failure.
Product Name: HVDA 5 Speed Conversions Make: Triumph Model: TR2, TR3, TR4, TR4A, TR6, TR250 Year: 1952, 1953, 1954, 1955, 1956, 1957, 1958, 1959, 1960, 1961, 1962, 1963, 1964, 1965, 1966, 1967, 1968, 1969, 1970, 1971, 1972, 1973, 1974, 1975, 1976