911 models 1972 - 1986
These cars are equipped with what is known as the 915 transmission. Originally pressed into service when the 911 had an engine capacity of 2.4 litres, it continued in service until 1986, by which time the 911 Carrera had an engine of 3.2 litres.
The 915 transmission is generally considered to be a blunter instrument than the G50 transmission that succeeded it, but it has a heritage that includes endurance racing, and properly maintained, and with new shift mechanism bushes, it’s every bit as good as you’d expect it to be.
Sloppy gear shifts are usually brought back to crispness with a replacement ball socket bush and shift rod tunnel bush. Occasionally the shift rod coupling bushes also need replacement, in which case we recommend using polygraphite bushes which provide a slightly firmer feel.
911 models 1987 - 1989
The G50 transmission-equipped Carrera 3.2 has a similar ball socket bush to the earlier cars, and a different shift rod bush. As with the earlier cars, these parts wear over time, gradually leading to a less precise shift feel.
911 models 1990 - 1998
The manual ‘box 964 and 993 continued with developments of the G50 transmission, but with a revised shift mechanism, which is generally trouble free.
Boxster, Cayman, 996 and 997
These cars have shift cables to operate the transmission. One cable handles left/right movement, while the other looks after fore and aft motions. We’re starting to see cars with shift cables nearing the end of their serviceable life. When that happens, we can offer Numeric Racing shift cables ex stock. The Numeric Racing cables are an improvement over the factory units.
We also carry the Numeric Racing performance shifter. This shifter is a thing of CNC engineered beauty, which includes options for reduced shifter throw. It fits within the centre console or, if you’d like to add some motorsport machismo to the cockpit, it can be mounted on risers to place the shift lever closer to your left hand.