7AT question
 

Yesterday I was out on a drive and ran over a small branch. It got kicked up into the undercarriage and got caught on some part of the transmission. It made a grinding noise. Sounded like maybe it got caught where the flywheel/flex-plate was? I was going ~20 MPH as the road was sketchy and pulled over right away. I think it somehow also got caught in the gear shift linkages, as I couldn't move the shifter from where it was in manual mode. I put the parking brake on, fought with the branch a little bit and got it free. Afterwards, the shifter works normally and the transmission shifts fine.

My question is, is it normal for something to be able get kicked up and disable the car like that? Shouldn't there be a protective plate/shield?

Sounds like just a freak occurrence, and not something that is expected to happen often.

I'm with XwChriswX - freak accident.

What confuses me is how it could jam the shifter. The 7AT is "fly-by-wire" and, as far as I can tell from the FSM, no part of the shifter mechanism is outside of the cabin.

There is a linkage from our shifter that connects to the tranny, you have to get completely under and look straight up, it helps to have someone run through the gears while you're under it. But there is one.

Thanks for clearing that up. :tiphat:

Edit: What is the mechanical link for? To make sure it goes into Park?

I've been thinking about it some more and I think the grinding noise was from gears. At first I thought that the branch might have got caught on something spinning, like the flywheel/flex-plate. But since it got caught on the shift linkages, it probably shifted the transmission into a different gear, or to park, or half-way between gears? The car was in gear though when I pulled over.

Never had anything like that happen before, even when off-roading (not in the 370z). Probably a lot better chance of hitting a deer, but I've never hit a deer before.

I believe so. I think there is a lock/pawl/ratchet that needs to be physically engaged. This is what keeps the wheels locked and keeps you from rolling when in park.

There are no "gear linkages" that go from gear to gear, from P to R to D, sure, mechanical

I once ran over a small piece of tire.. not that small. But small.

Anyways, it hit a skit plate or "something" under my car. Next thing you know, I am grinding in lower gears and on deceleration.

Long story short I was sketched out for a couple weeks and then it went away. Transmission was shifting fine though. Just made the grinding noise.

Most likely you got something caught and it was rubbing on the driveshaft. Makes a pretty horrible noise but the car will usually drive fine. Of course removing it as soon as possible is a really good idea, the driveshaft is an expensive piece on our cars.