Disassembling a manual transmission is a complex job but possible provided the proper steps are followed. Different models of vehicles can vary in their design, so anyone interested in attempting this task should check the repair manual for the model of vehicle they will be working with, but some steps are universal.
Find a workbench or table to work on. Find two blocks of wood thick enough to keep the mainshaft from touching the surface. You will also need a vise for later in the process.
The tools you need include a ratchet set, a plastic hammer, a normal hammer, two screwdrivers, a snap ring expander or a pair of snap ring pliers, a pin punch, a magnetic finger and an adjustable crescent wrench.
Place the transmission on the two blocks. Before you can begin dismantling it, you must first remove the release fork and bearing and the back-up light switch.
Remove the clutch housing from the transmission case. This involves removing a series of bolts from the front of the clutch housing. Using a socket wrench, remove the screw plug. Using a magnetic finger, remove the spring and ball. Using the socket wrench, remove the four bolts around the sides of the transmission shift lever control retainer, and then remove the shift lever control retainer. Remove the two restrict pins around the sides of where the transmission shift lever control retainer was. Remove the transfer adaptor. Some models may require a specialized tool to do this. Remove the eight bolts attaching the front bearing retainer and then remove the retainer. Using a snap ring expander or snap ring pliers, remove the two snap rings. Now stand the transmission so that the transmission case is pointing straight up. Use a plastic hammer to tap the transmission case lightly. Remove the transmission case from the intermediate plate.
Put the transmission case aside. Mount the intermediate plate in a vise. Remove the straight screw plugs, the locking balls,and the springs. Use a magnetic finger to remove the springs and balls from inside the intermediate plate. Use two screwdrivers and a hammer to pop the snap rings out of the fork shaft. Use a pin punch and hammer to remove the slotted spring pins from each of the fork shafts, and then remove the fork shafts. Remove the pins holding in the reverse shift arm, the reverse shift fork, and the shift fork shaft, and remove each of these in turn. Remove the shift fork shafts and the shift forks for all the gears in turn. Remove the splines and flanges in turn. Remove the spacer and ball. Remove the reverse shift arm bracket. Remove the reverse idler gear and shaft. Remove the rear bearing retainer, the counter gear, the input shaft and the output shaft.
