Changing from reverse to drive without stopping

[User33678888]

Years ago I was told to come to a complete stop when changing from reverse to drive on an automatic, for instance when backing out of a driveway.
More recently I was told that modern autos can deal with it, as long as its not above about 3mph. Is this correct?

[fat freddie]

You're still supposed to stop but modern autos won't engage D from R when on the move or vice versa, there's some safety gizmo inside the transmission that prevents it.
Think one of the car shows did a mythbuster-type test on one a few years back at 50mph and nothing happened.

[littleredrooster]

When Ford launched the Zodiac auto in the 60s, IIRC they did a demonstration for the press where they had Jackie Stewart driving a brand-new Zodiac on the Pit-straight at Brands. His instructions were to select D, floor the throttle, accelerate to 20mph and, without lifting the throttle, select R and come back to the starting point, then into D without lifting, then R...

If memory serves, he did this for over an hour before the press got bored and wandered off for 'refreshments' in their usual way.

[Clark3y]

The torque converter will allow for the slip yes, that's what they do.

[jamoor]

fat freddie said:

You're still supposed to stop but modern autos won't engage D from R when on the move or vice versa, there's some safety gizmo inside the transmission that prevents it.
Think one of the car shows did a mythbuster-type test on one a few years back at 50mph and nothing happened.

I tried doing it in a 1998 honda, it just clicked, I didn't try accelerating or anything though.

[vdp1]

My dad managed to put a Granada in park on the move once, albeit we were traveling quite slowly at the time. It was better than an emergency stop. Seemed ok after as well.

[B'stard Child]

I wouldn't do it in a manual - can't see why you would want to do it in an auto - regardless of it's ok or not according to the manufacturers a bit of mechanical sympathy goes a long way

PS Manufacturers say longlife oil in an autobox means no need to change it and I don't trust that either

[quiraing]

Just don't do it. If it's an older car you'll break it. Why would you want to do that??

[Willy Nilly]

I used to cart bales from a farm a few miles from here. He loaded me in the field with his telehandler. This if you don't know is a machine designed to go backwards and forwards all day every day. They have a powershuttle and torque converter. Just move the switch or lever to change direction. It is good practise to slow up and let off the power before shifting.

While the guy was loading me I noted he got in the cab, and put his foot hard on the floor and never let off. When he changed direction the wheels would be going forward and the machine would be going backward. He then proceeded to tell me what a piece of junk the machine was because he had no end of transmission problems with it. You don't say.

[redtwin]

quiraing said:

Just don't do it. If it's an older car you'll break it. Why would you want to do that??

To get proper tyre melting burnouts.

Well that's why I did it when I was 17.