So here's what happened:

After I'd finally settled in here in NYC after my cross-country trip, I went to pick up a friend at la guardia (I've got a car in New York!! First time!), and hit an epic pothole just over the Triboro bridge. Amazingly, tire and rim seem to be OK...

But. I get the blinking "D" (I'm going about 45), and it feels like the transmission is disengaged. Hit the gas and the engine just revs. I shift to N, slow down-- thankfully I'm headed downhill and there's an offramp. When I'm at about 10MPH, almost stopped, I try to shift back into D and hear some VERY unpleasant noises. I stop, shift into Park.. and cannot shift out of Park. I get the "Gearbox Failure" yellow triangle.

I turn off the engine. Wait a minute. Try again. Engine starts right up, shifter rises.... but can't shift out of Park. Same warning light. I'm screwed.

Now there's a NY State Trooper behind me. He's pissed. (I'm in a tough position). I show him the details, he kindly calls a tow truck, will stay behind me until the truck arrives. Not wanting to wear down the battery, I set the parking brake and step outside the car and lock it.

The tow truck driver arrives (15 minutes) and suggests I give it one more try. It starts. I can shift into D. I take my foot off the brake.... all seems good. No grinding, no nothing. The NY State trooper (very nice, actually) agrees to follow me back to Manhattan, and if I "get over the bridge onto the island" he'll take off.

All works. I nurse the car back-- no problems, it's running fine, I just decide not to push it. No sign of the "gearbox" light.

What should I do? Anyone have this happen to them? It's those few seconds of nasty clunking/grinding noises right before the car stopped (and that gearbox light and the fact that I COULDN'T MOVE THE CAR) that haunt me.

 

Follow up:

Got a space right in front of my building-- let my friend in, and didn't get back to the car for an hour or so.

At that point the car started up fine, drove to my parking garage with no symptoms or problems. (Less than a mile, never drive it over 30, but still.)

 

Did you bottom out when you hit the pothole? Also did you see any transmission fluid on the ground. You need to get the car on a lift and look under it to see if anything is damaged. I would get it checked out.

 

There also may be fault codes stored in the computer module(s) which should be checked out.

 

Sounds like you gave your tranny a concussion, probably jolted the electrical connections and valve body hard enough that it got confused and needed a shut down reset to reinitialize the drive train.

I would consider getting it scanned but I hope they won't be able to duplicate the fault. It seems the ZF trans is one of the tougher components on our cars. Electronics, not so much.

 

I can go with that.
Now explain the grinding.

 

Park driveshaft locking pawl trying to engage while moving makes a horrible world ending grind. Almost as bad as forgetting to double clutch an old Mack dump truck . In a cable operated car the lever disengages the pawl. I'm going to go out on a limb and assume that on a fully electronic shift trans that there's a solenoid that's supposed to hold it in the disengaged position. If the trans puter is confused it may have tried to go into park or 'forgot' to hold the park pawl. it's hard to say.

My best suggestion is to avoid pot holes and keep the car fully charged.

 

That's pretty good.
We should use you as a WH spokesperson and explain every train wreck.

Those damn potholes in Manhattan blew out a front wheel bearing on my 3/4 ton truck.

 

That was pretty cool of the state trooper to fall you like that.

 

Thanks all. Great answers, as always.
I did take a look underneath while waiting for a tow truck. No fluid that I could see.
Ranchero-- love "world ending grinding sound"-- that was it EXACTLY. But is it like the old starter solenoid (I hope)? When you try to start a car that's already running, and everyone within a hundred yards can hear that awful noise of some idiot trying to start a running car-- but it sounds a lot worse than it is?
Have driven the car around town twice since, without incident or warning light. No issues so far...