Well, that's not completely true, you can shift fully without hurting the transmission, it just takes too long for an effective shift. When you shift into neutral you are just releasing the attachment from the transmission to the differential. When you shift into gear you are connecting the selected gear with the differential. If their RPMs don't match up you can get grinding.ManualShifterHopefulMz3s said:
If a clutch goes out in a car and you need to drive it somewhere (which is hard to do if you can't idle) then you need to be able to shift without the clutch. If you are in 1st and want to shift to 2nd, put the car in neutral and ease up on the gas. Start shifting into second, but very carefully as you are back down on the accelerator. Keep a little pressure on the stick toward 2nd gear without causing grinding and when the RPMs of the driveshaft and 2nd gear match up you should be able to slide it into gear. This doesn't hurt the car, but this is very easy to do wrong so if you have a working clutch this process is not recommended.