In July, 1991 both Mitsubishi and Chrysler (who were selling badge-engineered Eagle Talon, Plymoth Laser and Dodge Stealth) issued a Technical Service Bulletin acknowleging an issue with shift quality and clashing (crunching) on the F5M21-F5M33 series manual transaxles.
According to Mitsubishi TSB 91-22-031 all transmissions built after 11 November, 1991 had modifications made to the 1-2 synchroniser hub and sleeve, the 1-2 synchroniser spring and the 3-4 synchroniser spring. Mitsubishi states that the improvements can be made to gearboxes made prior to 11/11/91 so long as the 1-2 synchroniser hub, sleeve and spring are changed at the same time. The 3-4 syncroniser spring can be changed by itself without affecting the rest of the 3-4 syncroniser assembly.
The 1-2 synchroniser sleeve, 1-2 spring, and 3-4 spring have been modified: the inner groove of the sleeve was made narrower, and the inner diameter of both springs were reduced.
For Australian models this TSB affects TN-TR Magnas with the KM210 (F5M31). The Australian F5M33 is unaffected as it was not introduced until 1993, after the modifications were made (although the modified part numbers below are the same for both the F5M31/KM210 and F5M33).
The parts required for the modification are:
- 1-2 synchro spring (New P/N: MD742455 Replaces: MD739065)
- 1-2 synchro hub and sleeve (New P/N: MD742465 Replaces: MD738868)
- 3-4 synchro spring (New P/N: MD742441 Replaces: MD738050)
Stealth/3000GT Archives - contains a copy of the Chrysler TSB