For starters I want to say hello and thanks for any feedback. I have a 2006 Mazda 3 sport that's been giving me "shakes" in the 1st and 2nd gear when I first launch off. The shakes are worser in the winter (Live in quebec) so I typically let it warm up 5 min before and it seems to help.

It does not do this every time. I'd even say its more on occassion but the shakes are violent enough to merit concern. After the car heats up they go away.

I changed the clutch and flywheel in 2008 because the original failed on me.

I already have a few pieces to change but if the clutch is bad it might be time to retire her. What could this issue be?

 

Worn gearbox & engine mounts maybe?
How's the overall driving & performance of the car?

 

Aside from the rust it performs great. Its not sluggish, has great acceleration, no strange noises from the motor. I know it needs a new alternator because sometimes it "chokes" before turning over. I've put synthetic in it every interval and it has no leaks anywhere.
Oh and its currently at 225k KM

 

I experience the exact same problem on my 2006- bucking in 1st or 2nd especially in the cold weather.

Other than being slightly annoying I don't see it as a huge issue. One person told me that when the engine starts cold, a gasket on the intake manifold can shrink to the point of causing inconsistent vacuum and causing the rpm's to fluctuate.