I am a mecanician and a change my clucth (pressure plate, clucth disc, resurfaced the flywheel and pilot bearind and clucth bearing) on my suzuki swift 2000 last winter. Since 2 or 3 month l have some rattle in the powertrain, only when the car is cold. The rattle is on the 1 2 and thrid gear. l change cv joint and wheel bearing, and the rattle is still there. After that l think that might be the differential in the transmission. l try another transmission and the rattle is still there.

When l bolt the flywheel to the crank l remember l use my impact gun to bolt the flywheel. l do not tork the bolt with a tork wrench.

The rattle can be cause by that? It is a clicking noise and some times we can feel the noise under the car in the middle. Just where the radio is but on the floor. It is not the engine mount l check it.

What do you think of that?
My next step is remove my other transmission and remove the clutch and flywheel, and tork ALL the bolts to spec, inspect all clutch component for dammage, and test the car after.

But l doubt that the presure plate have a broken sprink, or a broken spring on the clutch disc.
Do you mean the clutch bearing????

l drive normaly.

l remove the transmission and the clutch, and l see that one of the spring on the clucth disc is slack.
The flywheel have no crack, and the pressure plate is in perfect condition. The rear middle engine mount do not have slack. Next step bolt ALL the bolt on the clucth at the spec, and try the car.

Noise not in trans if you changed transmissions, has to be something else.

could be a cracked flywheel

maybe your clutch thrust bearing. Do you drive aggressively?