The compilers of this Guide do not recommend car owners to undertake the overhaul of manual transmissions on their own. During the disassembly and assembly procedures, the gearbox has to be removed and then replaced with many small components. It is necessary to make a lot of accurate measurements and, by selecting shims, rings and spacers, clearly set a lot of gaps. In view of the foregoing, it would be wiser to entrust the overhaul of the manual transmission to the car service specialists. Note that in many cases it is possible to purchase a refurbished unit on an exchange basis, which is often cheaper than a complex repair.
Despite the foregoing, the independent repair of the manual transmission by an amateur mechanic is not at all an absolutely impossible undertaking. Indispensable conditions are only the availability of the necessary special tools and accuracy in the approach to the implementation of all procedures.
Tools needed to rebuild manual transmissions include needle nose pliers for removing inner and outer circlips, a bearing puller, a sliding hammer, a set of drifts and center punches, a DTI gauge, and possibly a hydraulic press. In addition, of course, you will need a durable, vise-equipped workbench, or a special assembly stand.
During the manual transmission disassembly procedures, try to remember, or rather write down, the installation order of each of the removed parts.
Before proceeding with the disassembly of the gearbox, it would be wise to try to analyze the symptoms of its failures in order to approximately determine their causes. Many failures are uniquely related to the failure of well-defined components. See also the Manual Transmission Troubleshooting Section at the beginning of the Manual.