It is safe to install a used manual transmission because it is fairly easy to inspect and detect any problems with it before installation. Some transmission shops assist customers in locating used manual transmissions from salvage yards or used auto parts and recycled parts suppliers. Other shops indicate that the best option is always a new or rebuilt transmission if the customers budget allows and while shops do install used transmissions, many times there is no warranty on any costs.
The majority of replacement transmissions that auto repair shops install are not new transmissions. Most of the available units are rebuilt transmissions. Typically, professional manufacturers have disassembled and completely refurbished these transmissions and replaced any damaged or worn parts. Rebuilt manual transmissions typically come with a warranty that covers both the equipment and the labor used to install it.
Car owners who wish to save even more money can install used manual transmissions at home. The process is not difficult and only requires a few common tools. The owner needs to raise the vehicle on appropriate jack stands. The owner must use a jack to support the transmission and disconnect or remove all of the attached items, including the speedometer cable, drive shaft, gear shift control, transmission mount bolts and bell-housing bolts. The owner should then lower the unit from the vehicle and replace it.