Manual Transaxle
Manual Transaxle
Overview
The MTX-75 manual transaxle is a "2-shaft transaxle". MTX-75 means:
- M: Manual.
- T: Transaxle
- X: Transaxle (front wheel drive).
- 75: Distance between input and output shaft in mm.
The aluminum transaxle housing consists of two closed sections. The reinforcing ribs on the transaxle housing have been revised to reduce noise and vibration. As a result, the preload on the shafts and differential bearings has also increased.
To improve the lubrication of the third gear wheel, an additional drip plate has been fitted to the selector fork, allowing more transaxle fluid to drip onto the third gear synchronizer rings.
With the "2-shaft transaxle", all the gears are in permanent mesh. In each gear the required transaxle ratio is achieved by means of a pair of gears.
When the reverse gear is selected, the direction of the output shaft is changed by an idler gear.
The input and output shafts turn on taper roller bearings.
To further improve stability and gearshifting, the selector mechanism has been revised to incorporate a maintenance-free cable operating mechanism.
All the gears, including reverse, are bevel-cut, synchronized and turn on needle roller bearings.
First, second, and third gears have double synchronization. The advantages of this are that the transaxle operates quietly, gearshifts are smooth, and the assembly is compact and light weight.
Input and Output Shaft
Input and Output Shaft Overview
In neutral, none of the gears are connected to the input or output shaft via the relevant synchronizer unit. No torque is transmitted to the differential.
The input and output shafts are each seated in one taper roller bearing in the transaxle housing section on the clutch side and one taper roller bearing in the transaxle housing section on the transaxle side.
The output shaft drive pinion is in constant engagement with the differential drive annulus.
The third and fourth gears and the third/fourth gear synchronizer are located on the input shaft. The teeth for first and second and reverse gear are an integral part of the input shaft.
The first, second, fifth and reverse gears and the first/second gear synchronizer and fifth/reverse gear synchronizer are located on the output shaft. The teeth for third and forth gear are an integral part of the output shaft.
Differential
The main components of the differential are:
- Output gear wheel
- Spur gear
- Four pinions at right angles to one another
- Differential housing with two taper roller bearings
The transaxle and differential are installed in a two-part aluminum housing which is flange-mounted to the engine.
The driveshafts have serrated teeth and are secured with a snap ring.
The torque is transmitted from the spur gear to the driveshafts via two differential pinions mounted on the differential pinion shaft and the driveshaft pinions.
When cornering, the drive gears need to turn at different speeds as the road wheels travel different distances. This is achieved by means of the differential pinions which turn on their own shaft and mesh with the driveshaft pinions turning at different rates.
Power Flow
First gear
Second gear
Third gear
Fourth gear
Fifth gear
Reverse gear
Reverse gear idler
The reverse gear idler is driven by the input shaft. Its function is to reverse the direction of rotation of the output shaft in reverse gear.
The reverse gear idler is seated in a needle roller bearing on the idler shaft and also in a mounting.
Selector interlock mechanism
The selector interlock mechanism and the selector finger are mounted on a sleeve in the selector mechanism housing and keep the selected gear engaged with the aid of a spring-loaded ball until another gear is selected.
The selector interlock mechanism has three positions.
The reversing lamp switch is mounted on the side of the selector mechanism housing.
General Illustrations
Input shaft
Output shaft (right-hand side shown)
Output shaft (left-hand side shown)
Selector mechanism
Selector mechanism housing
Selector gate