# SHifting automatic into P while driving - what happens **URL:** \ **Category:** Factual Questions\ **Created:** [January 4, 2005, 11:15pm UTC](https://boards.straightdope.com/t/shifting-automatic-into-p-while-driving-what-happens/283105 "2005-01-04T23:15:56Z")\ **Posts on this page:** 15\ **Page:** 2
**Author:** ![cornflakes](https://avatars.discourse-cdn.com/v4/letter/c/9d8465/32.png) [@cornflakes](https://boards.straightdope.com/u/cornflakes)\ **Post date:** [January 5, 2005, 3:20pm UTC](https://boards.straightdope.com/t/shifting-automatic-into-p-while-driving-what-happens/283105/21 "2005-01-05T15:20:12Z")
> [@ntcrawler](#): > > Curious though, about shifting into R while driving. I know that on manuals you can’t do it because of the planetary gear system. You’ll hear a lovely grinding sound until the car is almost stationary, at which point it’ll click in. I would think that there would be a similar arrangement with automatics? Or is there a delayed reaction? Like **Gary T** said, it’s not a planetary gear. It is a nonsynchronized gear. The forward gears are designed so that their rotational speed matches up during shifts, causing smoother shifts. The reverse gear spins at whatever speed it likes until it is fully engaged. ---
**Author:** ![racer72](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/racer72/32/3075_2.png) [@racer72](https://boards.straightdope.com/u/racer72)\ **Post date:** [January 5, 2005, 3:59pm UTC](https://boards.straightdope.com/t/shifting-automatic-into-p-while-driving-what-happens/283105/22 "2005-01-05T15:59:43Z")
One of my first race cars was a 1966 Dodge Coronet, it was powered by a 383 and a 727 automatic transmission. During a race, I was hit from behind and started to spin out. While sliding at an angle, engine racing so it wouldn’t die, I knocked the shifter into park. Click, click, click, WHAM. I put the car back in gear and off I went to rejoin the race. After the race I pulled the car on my trailer, put it in park and started to climb out. The car started rolling backwards and I realized I have broke of the parking pall in the transmission. From that point on, park was just like neutral. I dropped the oil pan a few weeks later and the parking pall was laying in the pan. ---
**Author:** ![Mr.Goob](https://avatars.discourse-cdn.com/v4/letter/m/c77e96/32.png) [@Mr.Goob](https://boards.straightdope.com/u/Mr.Goob)\ **Post date:** [January 5, 2005, 4:55pm UTC](https://boards.straightdope.com/t/shifting-automatic-into-p-while-driving-what-happens/283105/23 "2005-01-05T16:55:17Z")
A friend of mine had a 1987 Grand Prix with the shifter on the console between the seats. Driving and having a fight with his girlfriend and she slammed it into park. He described it as the click click click sound of the pawl -then WHAMMMO it jerked to a to a stop while it was still rolling. I don’t remember what he said how fast it was going when it finally engaged, but it was enough to bounce him off the steering wheel. No long term damage to the tranny, unlike the windshiled she kicked out another time. Yes they eventually got married. ---
**Author:** ![Lemur866](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lemur866/32/434_2.png) [@Lemur866](https://boards.straightdope.com/u/Lemur866)\ **Post date:** [January 5, 2005, 5:10pm UTC](https://boards.straightdope.com/t/shifting-automatic-into-p-while-driving-what-happens/283105/24 "2005-01-05T17:10:23Z")
> [@Mr. Goob](#): > > No long term damage to the tranny, unlike the windshield she kicked out another time. > > Yes they eventually got married. There’s a really funny joke someone could do with this straight line. Too bad I’d be too naive and unsophisticated to understand it. ---
**Author:** ![gotpasswords](https://avatars.discourse-cdn.com/v4/letter/g/c57346/32.png) [@gotpasswords](https://boards.straightdope.com/u/gotpasswords)\ **Post date:** [January 5, 2005, 7:23pm UTC](https://boards.straightdope.com/t/shifting-automatic-into-p-while-driving-what-happens/283105/25 "2005-01-05T19:23:12Z")
> [@Tuckerfan](#): > > All I heard was a loud clicking sound and the car didn’t slow down a bit. Clicked once? You probably snapped off the parking pawl. They’re not the sturdiest part of the car, by any stretch of the imagination. In San Francisco, it’s not unheard of for some fool to forget about curbing their wheels on a hill and having the pawl snap off and the car rolls downhill. If they’re lucky, it just goes a couple feet and smacks into the downhill car. \* I once had to make an emergency brakes-out stop in a Chevy Citation. “It’s the first Chevy of the Eighties!” \* Shifted the tranny into Park, and nothing happened until I let go of the lever (Column shift, where pulling towards you is the equivalent to pressing a button on a console shift) and the pawl apparently hit at just the right instant and the car came to a very hard, tire-blowing stop. No, I don’t know how fast I was going as I was concentrating on how fast I was stopping. ---
**Author:** ![Gary\_Robson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gary_robson/32/3448_2.png) [@Gary\_Robson](https://boards.straightdope.com/u/Gary_Robson)\ **Post date:** [January 5, 2005, 8:13pm UTC](https://boards.straightdope.com/t/shifting-automatic-into-p-while-driving-what-happens/283105/26 "2005-01-05T20:13:12Z")
> [@The Cat](#): > > In every car I’ve driven after you turn the key into the on position and shift it into drive, you can’t shift it back into park until you turn the key back to the off position. What country are you in? I’ve been driving for almost 30 years now in the U.S., and during my travels I’ve rented cars in Canada, Mexico, and several European countries. I’ve _never_ encountered a car that wouldn’t go back into park with the engine running, as long as you stopped moving first. > [@Bryan Ekers](#): > > An erstwhile but short-sighted constable is trying to prove a semi-retarded woman knows how to drive a car (if she can, it’ll lend evidence that she’s the masked assailant of local dwarves - it’s complicated). He puts her in the driver’s seat of a standard-transmission police car… What is an erstwhile constable doing with a police car? Did he steal it? Keep it when he left the force? ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [January 5, 2005, 8:14pm UTC](https://boards.straightdope.com/t/shifting-automatic-into-p-while-driving-what-happens/283105/27 "2005-01-05T20:14:44Z")
I have noticed on one car in particular (80 Dodge Omni) that when in park and the wheels elevated (w/ jack stands) that if you turn one wheel by hand the other spins in the opposite direction. I think if the car is in N this doesn’t happen, but can’t recall. Also applying the parking brake has not cause any lockup or sudden stops in any car I tryed it with (on dry pavement, snow is another story), which is most. Usually it causes a very slight braking effect. ---
**Author:** ![Tuckerfan](https://avatars.discourse-cdn.com/v4/letter/t/eada6e/32.png) [@Tuckerfan](https://boards.straightdope.com/u/Tuckerfan)\ **Post date:** [January 5, 2005, 10:06pm UTC](https://boards.straightdope.com/t/shifting-automatic-into-p-while-driving-what-happens/283105/28 "2005-01-05T22:06:35Z")
> [@gotpasswords](#): > > Clicked once? You probably snapped off the parking pawl. They’re not the sturdiest part of the car, by any stretch of the imagination. In San Francisco, it’s not unheard of for some fool to forget about curbing their wheels on a hill and having the pawl snap off and the car rolls downhill. If they’re lucky, it just goes a couple feet and smacks into the downhill car. Didn’t click once, it kept on clicking until I janked it out of gear. Certainly didn’t snap the pawl as I had no trouble with the car staying in park after that. ---
**Author:** ![Bryan\_Ekers](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bryan_ekers/32/183_2.png) [@Bryan\_Ekers](https://boards.straightdope.com/u/Bryan_Ekers)\ **Post date:** [January 5, 2005, 11:15pm UTC](https://boards.straightdope.com/t/shifting-automatic-into-p-while-driving-what-happens/283105/29 "2005-01-05T23:15:00Z")
> [@InvisibleWombat](#): > > What is an erstwhile constable doing with a police car? Did he steal it? Keep it when he left the force? Everybody’s a comedian. I meant to type _earnest_. Though I suppose if he _used_ to be that way, he’d be earnestwhile. ---
**Author:** ![spingears](https://avatars.discourse-cdn.com/v4/letter/s/ebca7d/32.png) [@spingears](https://boards.straightdope.com/u/spingears)\ **Post date:** [January 6, 2005, 2:41am UTC](https://boards.straightdope.com/t/shifting-automatic-into-p-while-driving-what-happens/283105/30 "2005-01-06T02:41:25Z")
> [@The Cat](#): > > In every car I’ve driven after you turn the key into the on position and shift it into drive, you can’t shift it back into park until you turn the key back to the off position. As I’ve always owned manual car i’m constantly trying to shift automatics into park before i turn the car off. This is true for all cars I’ve driven, but the oldest car I’ve driven is an 81 riviera, so I’m not sure if it would be possible in older cars. I drive a 94 Buick Rgeal. When parking I shift into neutral while holding the foot brake, set the parking brake, put the shift into park and shut off the engine. When the engine is off the shift lever is locked. ---
**Author:** ![Bryan\_Ekers](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bryan_ekers/32/183_2.png) [@Bryan\_Ekers](https://boards.straightdope.com/u/Bryan_Ekers)\ **Post date:** [January 6, 2005, 3:24am UTC](https://boards.straightdope.com/t/shifting-automatic-into-p-while-driving-what-happens/283105/31 "2005-01-06T03:24:16Z")
> [@spingears](#): > > When the engine is off the shift lever is locked. If your car is anything like my '90 Camry, you can turn the ignition key to first position (i.e. before starting the engine) and release the gear shift (though you have to press the brake before leaving “park”), allowing you to roll as gravity suggests. ---
**Author:** ![Sunspace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sunspace/32/1250_2.png) [@Sunspace](https://boards.straightdope.com/u/Sunspace)\ **Post date:** [January 6, 2005, 3:35am UTC](https://boards.straightdope.com/t/shifting-automatic-into-p-while-driving-what-happens/283105/32 "2005-01-06T03:35:16Z")
> [@Martin Hyde](#): > > Firstly I was under the impression that pulling the parking break while you’re travelling causes very rapid and dangerous stopping (locking wheels et cetera.) Well as I learned one day many years ago, it does not. I discovered if you find yourself moving down a hill in a manual and can’t stop yourself your best bet is to move it into neutral and apply the parking break over and over again. When I was at university my friend had a Fiat. We went out on the freeway, whereupon he started to use the parking brake to slow down. It was at this point that he announced that his regular brakes weren’t working, and the careful use of the parking brake was all that stood between us and fiery doom… ---
**Author:** ![jasonh300](https://avatars.discourse-cdn.com/v4/letter/j/46a35a/32.png) [@jasonh300](https://boards.straightdope.com/u/jasonh300)\ **Post date:** [January 6, 2005, 11:01pm UTC](https://boards.straightdope.com/t/shifting-automatic-into-p-while-driving-what-happens/283105/33 "2005-01-06T23:01:57Z")
> [@kanicbird](#): > > I have noticed on one car in particular (80 Dodge Omni) that when in park and the wheels elevated (w/ jack stands) that if you turn one wheel by hand the other spins in the opposite direction. I think if the car is in N this doesn’t happen, but can’t recall… Refreshing this thread to see if anybody has an explanation for this. I think it has to do with the differential and the drive shaft being locked by the parking pawl…if the drive shaft isn’t turning the back wheels (RWD) will rotate in opposite directions. And I also think that on a car with positraction, this won’t happen. Anybody know for sure? I noticed this once on an old Datsun 280ZX that was being pulled onto a flatbed tow truck while it was in park…the wheel closest to me was turning the wrong way. ---
**Author:** ![Richard\_Pearse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/richard_pearse/32/13144_2.png) [@Richard\_Pearse](https://boards.straightdope.com/u/Richard_Pearse)\ **Post date:** [January 7, 2005, 5:17am UTC](https://boards.straightdope.com/t/shifting-automatic-into-p-while-driving-what-happens/283105/34 "2005-01-07T05:17:33Z")
I think it is common to all cars, not just automatics, and it is a function of the differential. ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [January 7, 2005, 9:12am UTC](https://boards.straightdope.com/t/shifting-automatic-into-p-while-driving-what-happens/283105/35 "2005-01-07T09:12:18Z")
> [@InvisibleWombat](#): > > What country are you in? I’ve been driving for almost 30 years now in the U.S., and during my travels I’ve rented cars in Canada, Mexico, and several European countries. I’ve _never_ encountered a car that wouldn’t go back into park with the engine running, as long as you stopped moving first. Neither have I, and I’ve driven around quite a bit, too. It seems rather dumb to only let your car shift into park if the engine’s off. Turning off the car while it’s still in gear seems so unnatural. [Previous page](https://boards.straightdope.com/t/shifting-automatic-into-p-while-driving-what-happens/283105.md?page=1)