KM210
The KM210 (also known as the F5M31) represented a significant leap in engineering for Mitsubishi’s mid-sized sedan range. Replacing the experimental design of the KM164, the KM210 served as the workhorse manual transmission for the TN through TS four-cylinder Magna models.
The primary distinction of the KM210 was the move to a conventional constant-mesh architecture. While the predecessor (KM164) was essentially a "4+1" setup that relied on a vacuum-actuated high/low range on the input shaft, the KM210 utilized a dedicated 5th gear set. Gone were the vacuum servos and electrical switches of the previous generation. 5th gear was now engaged via a direct mechanical link from the gear selector, improving tactile feedback and long-term reliability. By integrating 5th gear onto the main output shaft alongside gears 1 through 4, the transaxle achieved a more compact and robust internal configuration.
Because it was designed with a higher "torque ceiling" than the KM164, the KM210/F5M31 was a global platform component. While Australians saw it in the naturally aspirated 2.6L Astron engines, overseas markets utilized this gearbox in high-performance applications:
- Turbocharged Applications: It was commonly paired with Mitsubishi’s turbocharged 4G63 engines in models like the Galant VR-4 and the Eclipse.
- Robust Housing: The casting was reinforced to handle the increased torsional stress of forced induction, making it one of Mitsubishi's most durable manual transaxles of that era.
Despite its strength, the KM210 has a reputation for gear crunching on downchanges, normally when going into 2nd and 3rd gear. The problem was caused by a faulty 1-2 syncroniser assembly and a faulty 3-4 syncroniser spring. This problem was acknowledged by Mitsubishi in a Technical Service Bulletin.
Technical data
| Lubricant | 75W/85W Hypoid Gear Oil | |
| Capacity | 2.5 Litres | |
| Clutch Plate Diameter | 225 mm | |
| Clutch Operation | Hydraulic | |
| GEAR RATIOS | ||
| Final Drive | 3.411 | |
| 1st | 3.166 | |
| 2nd | 1.833 | |
| 3rd | 1.240 | |
| 4th | 0.896 | |
| 5th | 0.666 | |
| Reverse | 3.166 |
