Autohous Hamilton has got gearbox parts for six cylinder Porsche cars from 1972 to 2012.

We have deep knowledge of every model and we know all the tricks when it comes to improve gear shifting.

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 have proved remarkably trouble free over the years. However, these cars are now reaching an age where their shift linkages are starting to wear, which means replacing the shift rod and its front bushing.

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 to maintain standard appreaeance 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.