I’m driving down the freeway and I decide I want to slam the transmission into reverse or park. What will happen? Will I need a new transmission?
This didn’t happen, I’m just wondering.
You’ll at least shear off the pin that fits in place to stop the car from moving when parked.
Wasn’t this a Mythbusters episode? They did shear off the pin in park, but I don’t remember what happened with shifting into reverse.
I did it in my '64 Ford Falcon, shifted into reverse while moving that is. I needed to keep my RPMs up because of a faulty oil pump (low oil pressure), so I’d just shift into neutral at stops. I was going about 20 miles an hour or so, and accidentally shifted into reverse instead while coming to a stop sign. Some shuddering and screeching of tires occurred, but I made it out all right. That 2 speed slushbox could probably take a lot of abuse, though.
I am always tempted to do this while zooming down a highway. I don’t know why this is.
-FrL-
The tapering of the gear that the nub lands in is spinning too fast to ever lock over 5mph. It will just click (in pain) until you slow down enough.
It would take hours of abuse for the nub to become ineffective and there is zero possibility of one shearing off unless there is some gross metallurgical flaw or factory defect.
I am too young to know if a “pin” was ever used, but I would hazard to guess that whoever may have implemented an unforgiving pin in the past instead of a tolerant nub-on-taper in a transmission would be a legend… and not a good legend like MacPherson, but more of a legend like Yugo motorcar corp.
The Mythbusters episode that covered this was on yesterday. They used two cars: an automatic and a manual transmission. All tests were run at 50mph.
For the automatic car, nothing happened when they threw it in reverse, and nothing happened when they threw in it park. Aside from some warning lights coming on, the car just kept going down the track. It seems cars have safety features that cover these scenarios.
For the manual transmission, they tried to shift into reverse but couldn’t. He was grinding the gears like crazy, but it wouldn’t go. Turns out you can only get it into reverse when the car is stopped (or pretty close to it).
I don’t recall the makes/models/years used in the tests. Your mileage may vary. Not available in all areas. Check your local listings. Professional driver on closed track.
About 39 years ago or so when I was taking driving lessons the instructor had both me and another student in the car. Believe it or not, the other student pushed the gear lever when he meant to push the turn signal :eek:. He did manage to get it into reverse and the car came to a very jerky stop in 1/2 a block or so. No idea what kind of car it was other than it was an automatic. The car seemed to work OK afterwards.
I have a 94 Thunderbird and this is my story. Years ago, I was driving down the highway. I was passing someone doing about 40 MPH and pulled the shifter down to 2. (I was young.) When I passed them, I intended to put it back in drive. However, I just reflexively went all the way forward into park. I realized this immediately and within a split second, pulled it back down to drive. It was enough to lock up the tires momentarily. I’ve been told they more likely locked up from crossing reverse than being in park. I don’t think the car suffered any damage from my faux pas.
And just for your information, when you hit the speed limiter in neutral going down a hill, the engine dies. Not a good time to lose power steering and brakes…
The answer is it depends on the car.
On some cars putting the car in reverse, the car will go into reverse, and probably lock the rear tires, and possibly stall the engine*. Putting it into park will result in the parking pawl clicking along as it tries to engage the slot on the output shaft. It is possible to shear off the parking pawl by doing this at a few miles per hour, the pawl engages and is stressed past it breaking point. Over the years I have seen several cars that have had the parking pawl sheared off. When I would get one of these cars, I often wished that cars had black boxes like airplanes. I really wonder just how people do some of these things.
On other more modern cars, the electronic control module won’t allow the engagement of reverse when the car is in motion. R is the same as N on these cars. Park is still a mechanical connection, and you would have a repeat of the above scenario by putting the car in park.
The third variation is there is a solenoid that prevents the shift lever from going past N to R or P if the car is in motion.
I have never seen a car that allows the shifter to go to P but doesn’t engage the parking pawl mechanically. I don’t doubt it is possible, but I am not aware of such a system.
*Been there done that. Probably not good for the transmission either.
There used to be a lot of legends floating about concerning what happened with old Dodge/Chrysler “typewriter” transmissions when you accidently pushed the reverse button, since the design made it likely to happen. Those are so ancient now that you don’t hear anything about them anymore.
Once while traveling down the freeway at approx 55mph, I put the car into reverse just to see what would happen (I was young and irresponsible, plus it was a rental). Anyway the car just stalled. Not sure if it damaged the transmission or not.
I’ve dumped an automatic transmission into reverse while doing about 30 MPH before. (Accident, as I was unfamiliar with the vehicle I was driving and grabbed the wrong thing. I was trying to adjust the steering wheel.) The vehicle (a Suburban) stalled out, and didn’t have any significant transmission problems afterwards.
I’ve also thrown a car (65 Ford Ranchero) into park at low speed. (Brakes failed, and I was trying to stop the car.) Lots of clicking, but no damage to the transmission. Didn’t even stop the car, I had to shut the engine off, and do a Fred Flintstone.
See my post above, the tires lock and sometimes the engine stalls.
It was my father trying to put the car in low for a hill, and hit the R button instead. Honest.
See my 64 Ford Falcon post above (Same damn car, practically). Shoulda gone to reverse!
This would strike me as being against the principle of P in the first place, in that it’s a fail-safe should (all) other mechanisms fail. For this reason, its operation should be isolated from all others, and adding a cut-out contradicts this.
My pontiac Bonneville a few years ago would, when switched to reverse, feel like it’d stall out and then reverse, up to about 3 mph. Over that, it’d just stall. From reverse to drive, it’d engage up to about 9 MPH.
It’s the imp of the perverse. Mine is throwing the steering wheel hard right while doing 60 MPH. A sideways flip ×10 would be my guess on the result.
Anybody want to go for a ride?
They need a 77 Datsun b210 5 speed manual…not sure if they even came in an auto.
anyway the shifter was all kinds of jacked up with first in the second gear spot and reverse in first gears normal spot with absolutely ZERO safety systems in place, going into reverse was just like any other gear. yeah one time I shifted wrong on the freeway and hit reverse…it just popped right into the slot with a bit of resistance but not much, I didnt drop the clutch because I knew something strange had happened but it was in place…
Being an “old-guy”, I drive so slow that my teenagers claim I get bug splats on the rear window of my car so… What on earth is a speed limiter?
(sorry 'bout the hijack, just curious)
I am not completely sure in this context but some cars have a computer override that won’t let you go past a certain RPM and/or a certain speed. My BMW had one that kicked in at 118 mph and I hit it a few times. It feels a little strange to know your car is going all parenty on you you.