See Figures 1 through 8
The 1983-95 Monteros and Pick-up trucks came equipped with a possible number of 6 different manual transmissions, with the differences being whether the vehicle has 2- or 4-wheel drive, what engine the vehicle came equipped with, or what years the vehicle was manufactured in. The six transmissions are as follows: KM 130 (2-wheel drive/2WD), KM 132 (2WD), R5M21 (2WD), V5M21 (4WD), KM 145 (4WD), V5MT1 (4WD).
The KM 130 and KM 132 transmissions are internally identical, with the basic difference in the shifter assemblies. The KM 145 is the KM 132 transmission with a transfer case attached for 4WD vehicles. The transfer unit is removable. These transmissions incorporate 5 (4 for the KM 130) forward gears (the fifth gear being an overdrive gear) and a reverse gear. They are fully synchronized in all forward gears and reverse. All gear changes are accomplished with the assistance of synchronizer sleeves. Reverse gear uses a reverse idler gear which is in constant mesh with the countershaft gear.
The top mounted shifter operates the shift rails through a set of shift forks. Shift forks mounted on the rails operate the synchronizer sleeves that allow shifting of the 1/2, 3/4 and overdrive/reverse.
A shift interlock system, located in the side of the transmission case, prevents the shift rails from engaging 2 gears at the same time.
The transmission assembly is composed of 5 major components: a front bearing retainer, a transmission case, a transfer case adapter and a control housing, all of which are cast aluminum. The fifth component is the under cover which is made from stamped aluminum.
The Mitsubishi KM 130, KM 132 and KM 145 can be identified by an identification code. This code can be found on the transmission identification tag located on the side of the transmission case.
The R5M21, V5MT1 and V5M21 are the newer replacements for the KM 130, KM 132 and the KM 145. These transmissions are in the Monteros and Pick-up trucks from 1990-95. They are essentially the same, also being five speed transmissions. The V5M21 and the V5MT1 are 4-wheel drive transmissions and, therefore, have a transfer case attached to them.
Due to the large number of alloy parts used in the transmissions, torque specifications should be strictly observed. Before installing cap screws into aluminum parts, dip the bolts into clean transmission fluid as this will prevent the screws from galling the aluminum threads, thus causing damage.