At GCAP we offer complete gearbox overhauls. Everything from bearing replacement to exchange boxes ready to ship.

We are an M32 gearbox specialist found in the Astra, Corsa, Meriva and Zafira VXRs. The box is also found in many of the Alfra Romeo, Fiat and Lotus marques. Some common problems range from gearstick play, whining, popping out of gear and difficulty selecting gear.

Usually the main cause of the issue is bearing wear (more so, the bearing on top of 6th gear). 1st, 2nd, 5th and 6th are all on the same shaft, so issues will manifest over all these gears usually. Reverse, 3rd and 4th gear are situated on the other output shaft, so that group would suffer together collectively as well. The reason for failure is largely due to excessive temperatures inside the box, lack of servicing (as per GM’s instructions), but ultimately, a poor gearbox design.

We do not offer an in-situ repair on any gearbox rebuilds. We prefer to do the job correctly by removing the box, stripping apart, cleaning all internals, installing all new bearings, correctly shimming the box with Kent Moore toolsets and reassembly. We then install the box with better quality gearbox fluid. All this ensures a thorough and extensive repair, in which we are confident it will be stronger than how it left the factory. We only use Timken bearings and offer a no quibble 1 year warranty on all boxes.


We also offer full rebuilds on most manual, semi auto, automatic and DSG boxes.

If your box is in general good health but you would like a complete dealer level service on it we can carry out a full inspection and service using only genuine manufacturer fluids.

We use the latest diagnostic equipment to ensure that once we have changed the filter and fluid, we can monitor temperature and operation of the box to ensure good working order.


With most car manufacturers not building vehicles with the intention of them being pushed to their limit be it on the road or track, they tend to leave the differential to a very modest spec.

We can offer limited slip differentials for most cars from some of the leading transmission specialists such as Quaife, Wavetrac, Gripper etc.



GCAP Performance

6 Powis Mews

Notting Hill


W11 1JN