Models 4.2 l
On 4.2 liter carburetor models, the FS5R50A manual transmission is installed with five forward gears and one reverse gear, all of which (including rear) synchronized.
All driven gears are helical and are in constant mesh with the countershaft gears. Gears of the first, second, third and reverse gears are mounted on roller bearings on the driven shaft. The fifth gear is also mounted on a roller bearing on the intermediate shaft. The reverse intermediate gear is mounted on a separate shaft by means of roller bearings.
A spring-loaded gear ring is installed in front of the intermediate shaft in order to minimize the backlash of the gear set.
Gear shifting is carried out by articulating the gear with the synchronizer assembly by introducing the internal splines of the synchronizer clutch into engagement with the synchronizer teeth of the corresponding gear. Synchronization is achieved when the synchronizer ring comes into contact with the cone on the gear wall, which causes the gear and synchronizer assembly to rotate at the same speed, ensuring smooth shifting.
The input shaft rotates in a ball bearing located at the front of the gearbox and contains a roller bearing, which includes the front pin of the driven shaft. The rear part of the input shaft is supported by two ball bearings, one of which is located in the box crankcase, and the second in the extension housing.
A removable cover is fixed on the left wall of the transmission housing, which serves to remove / install the power take-off unit (RTO).
Later 4.2L EFI models use a modified FS5R50A transmission with revised gear ratios (see tables of sizes and adjustments at the end of the guide). Here, the number of teeth of the input shaft drive gear is increased to 27, and the countershaft driven gear is reduced to 34. First and third gears are equipped with synchronizers with double blocking rings.
Models 3.0 l
The 3.0L model also has a fully synchronized FS5R30A manual transmission with five forward gears and one reverse.
The forward gears are helical and are in constant mesh with the countershaft gear group. The gears of the first, second and third gears on roller bearings are mounted on the driven shaft of the box, the gear of the fifth gear is also mounted on the intermediate shaft on a roller bearing. The reverse intermediate gear is located on a separate shaft and is equipped with two roller bearings.
Synchronization when shifting gears is achieved in the same way as in FS5R50A boxes of 4.2 liter models.
The input shaft rotates in a ball bearing located at the front of the gearbox and contains a roller bearing, which includes the front pin of the driven shaft.
The driven shaft rotates with bearings located in the carrier plate and extension housing, while the intermediate shaft bearings are located in the clutch housing and carrier plate.