Hard Shifts? Normal or not?

[fattycharged]

I can't understand how the clunk happens in this scenario. On 0 to 1, car stands still so driveshaft speed = 0. To engage 1st gears, the synchro has to stop the spinning input shaft by friction, then the slider can engage the first gear dog teeth without making the grinding noise. So with the clutch disk and input shaft stopped when the gears are engaged, so does the diff input, how does the clunk happen? The only way to have the clunk is the long driveshaft must be rotate or try to rotate, this means the clutch disk and input shaft were rotating when the gears engaged, but this should cause gear grinding inside the tranny box.

When was last time you had the vehicle running and stared at the driveshaft?


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[sapote]

When was last time you had the vehicle running and stared at the driveshaft?


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1. in neutral, rear wheels free in air and no hand brake, wheels are turning by the oil viscous friction in the gear-to-shaft roller bearing and so the driveshaft is rotating. But when wheels on ground, nothing to the driveshaft.
2. car on ground, 0 to 1 shift, driveshaft should not turn when gears engaged on a normal working car at stop, unless the old clutch is about to explode any moment.