Did you ever think what will happen if you put the gear from Drive to Shift? The first two questions might be tough cookies, but the last one is tempting enough to make you actually try the feat! After all, the answer is merely a couple of clicks away!
Of course, the act is NEVER recommended since, in theory, the gears moving forward have to come to a complete halt before they are to be reversed. Naturally one would picture ball bearings splattering out and gear fragments grinding into pieces if a full speed car was to be reversed. But is that really what happens?
As it turns out, automotive engineers are clever enough to recognize such wild ideas and have preemptively put safety checks in the cars. For automatic transmissions, nothing happens since automotive engineers place a function called Reverse Inhibit that prevents this selection when on high forward speeds.
Craig Renneker, Ford’s Chief Engineer for transmission, says,
“Putting it into reverse [in modern cars] when going forward has no action at all, the car just ignores the request until you get down to a proper speed,” said Renneker, using Ford’s six-speed automatics as an example; “It’ll just say ‘hey, I know you want reverse pal, but I’m just not going to give it to you until the appropriate time.’”
Manual transmissions come with physical locks in the shape of lockout rings in the gear mechanism that makes selecting reverse an impossible task.
“The main problem you’re going to be fighting is what you’re trying to get the thing to do is something it really does not want to do,” Renneker continued.
As many of us already know, the manual gear set would growl and grind if you mistakenly tried to put reverse when on high speeds. The synchronizer mechanism in manual cars can only change the speed of transmission for smooth engagement and force it to match shaft speeds while putting it in reverse could damage it beyond repair.