Introduction to The Greasy Hands Garage Guide to Rebuilding the Triumph TR Transmission and Overdrive
Larry Young and Sam Clark, Green Country Triumphs Revised: May 5, 2006
The following documentation was gathered during the rebuild of the three transmissions shown below: (1) TR3 s/n TS24066 with overdrive model 22/1374 (2) TR4 s/n CT21820 with overdrive model 28/1447 and (3) TR6 s/n CC109568 without overdrive. These transmissions encompass most of the variations throughout the productions of the Triumph TR2-6. They are also typical of the rebuilds we encounter at the Greasy Hands Garage. The TR3 tranny came from a parts car that our club purchased from an estate. It had several large holes drilled in the main housing, so we used a replacement housing TS65635. Those from the TR4 and TR6 were donated to the club by members. The overdrive unit from the TR4 must have come originally from an Austin Healey, since Triumph never fitted this model at the factory.
I should make a statement about our qualifications. We don’t have any, other than that we’ve rebuilt about a dozen transmissions and worked on a half dozen or so overdrives. We make no claims about any of this material. These methods work for us.