The 4 speed is bulletproof. My car's engine was replaced after neglect before the first clutch was changed. They are definately extremely heavy duty. I can remember taxi drivers in the Azores going like mad, bucking the car, doing various things for quick take offs, extremely hard shifting...amazed the syncromesh lasted a day with their psychotic driving. From what I've heard, European 5spd tranny in the 300D is a totally different machine for reliabilities sake....when it's cold the tranny in my car is a bit stiff...let it idle for 5-8 minutes, and its nice again.