I went up to 6 rpm and then tried to shift to second gear aggressively and unknowingly the clutch was not fully depressed I think and the gear change failed of course I heard the gears grinding but I also felt something stop moving in the gear knob while holding it. The car drove fine after that but how much damage did I do to the transmission?

2 Answers 2


By failing to fully disengage the clutch, you mashed the very fast spinning input shaft gears with the not as fast spinning second gear. While the synchro will have helped lessen the difference in speed, there's only so much it can do, and you probably damaged some of the teeth. Considering that the car still shifts and drives fine, I would go ahead and change your transmission fluid, and don't be surprised when you find some metal flakes in there. You should also make sure you have a magnetic drain bolt, which will help collect any metal shavings that break off when miss-shifts occur.


Probably Nothing

I don't know what your car model and year are but most modern vehicles have what is called a rev limiter.

Rev limiters are typically electric in nature and cut out the ignition spark on cylinders when the RPM's exceed the manufacturers max limit on the engine.

This prevents the engine from getting damage due to excessive RPM's.

IF (and I know you didn't) you went from 4th gear to 2nd at 70mph, or something like this, the rev limiter would do you know good because you engine RPM's would not be controlled by combustion at that time. They would be controlled by the rotation of the tires and a direct connection to your engine via the transmission.

I have seen young people put their foot on the gas and take it to the floor in neutral and just run their engine against the rev limiter a few times, just to make the noise. I will say this isn't good for you car and I don't recommend doing it.


You have a safety mechanism that prevents damage to your vehicle when you encounter a situation like you did. Missing a shift won't hurt a modern vehicle with a rev limiter. You should have nothing to worry about.

  • 1
    You misunderstood me. I was at first gear trying to shift to second very aggressively and failed the ahift
    – method
    Feb 11, 2016 at 3:14
  • no, I understand. I put out a scenerio that would damage your car. If you went from 4th to 2nd, you would be screwed. Missing a shift just makes your engine hit the rev limiter, it's fine. Feb 11, 2016 at 3:31
  • I added stuff to clarify. reread it. Feb 11, 2016 at 3:33
  • I don't see how the rev limitter affects my case when up shifting my rpm would drop not go higher so why would I hlbe concerned about the motor revolutions in this case what I am asking about is to what extent I damaged my transmission from failing to shift with the clutch not being fully depressed very aggressively and at such high RPM
    – method
    Feb 11, 2016 at 3:39
  • 1
    Usually when a person shifts he releases the throttle, I don't think RPM is related to the question. As I understand the problem here is failing to engage a gear because of not fully depressed clutch and the damage that could cause (because of unsynchronized gears trying to engage). Feb 11, 2016 at 8:18

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