There are all kinds of reasons for removing the manual transmission in a Chevrolet vehicle --- for repairs, replacement, or to change the manual vehicle into an automatic. Starting the process, however, can be rather difficult without training and reliable information. Although transmission removal is a tricky process, it can be done by the amateur mechanic with the right tools and information.
A number of tools will help the removal process go much more smoothly. The most important tools are sockets, wrenches, and lifts. A full mechanic's socket set with varying socket sizes is an absolute necessity. Wrenches ranging in size from 10 mm to 17 mm will usually suffice. Removal also necessitates a quality jack and set of lifts to ensure that the car stays elevated during the job. A transmission jack will help move the piece into and out of place. Of course, depending on the job (clutch or transmission replacement, etc.), you will need the necessary replacement pieces. Gear oil, grease, duct tape, and other essentials should be prepared beforehand --- even if they're not needed, it's easier to have them around while the job is being done than to have to run out dirty in the middle because you've forgotten them. As transmission removal is an involved process, a helpful buddy or two wouldn't hurt to have around.
All of the codes and transmission actions should be written down beforehand, so as to avoid confusion later on. If the vehicle is equipped with airbags, the system will have to be deactivated before attempting to remove the transmission. Airbag deactivation varies from Chevrolet vehicle to vehicle, so factory instructions must be followed to the letter. Finally, the battery must be disconnected in the vehicle to proceed. Because the vehicle's computer and memory can lose information through this process, it is important to look at the vehicle's Computer Relearn Procedures in the owner's manual to see if data can be backed up or replaced after transmission removal.
The transmission shift lever must be removed first and should be covered with a rag during the job. Next, transmission oil must be drained: this can be accomplished by raising the vehicle. Disconnect the battery cables and move the gearshift into a neutral position. Remove all skid plates, struts that connect the engine to the transmission, and any exhaust components connected to the transmission. This may include mufflers and catalytic converters. The drive shaft, shift linkage, control cables and appertaining wiring must be removed next --- leaving any connected may result in costly repairs just for the car to begin running again. For certain Chevys, transfer cases and speed sensors will need to be disconnected or removed. The two bolts on the clutch release cylinder must be disconnected, and heat shields removed. Starter and converter inspection covers should be unbolted and removed. Clear any additional lines --- wires, cooler lines, filler tube --- and the transmission must be harnessed into the jack and lowered slowly. Do this 1 to 3 inches at a time, making sure that it's clear from any connections. If done properly, the transmission should now be free and clear.
