Automatic gearboxes - Dave H
Not being used to automatic cars and having recently borrowed one, could some kind soul tell me whether the handbrake needs to be on when the gearbox is in Park?


Dave H
Automatic gearboxes - frostbite
Well, my handbrake only gets used at MOT time, but I bet there will be plenty expressing horror at that!
Automatic gearboxes - Ian (Cape Town)
best thinking:
foot on brake, put into Park, pull up handbrake.
Also, when stopping in traffic: foot on brake, wait until car behind is stationary, pull up handbrake to avoid brake-light blind.
when parking on a hill, turn wheels away from kerb full lock. (if facing up), or towards kurb full-lock (if going down)
Automatic gearboxes - Martin Devon
best thinking:
foot on brake, put into Park, pull up handbrake.
Also, when stopping in traffic: foot on brake, wait until car
behind is stationary, pull up handbrake to avoid brake-light blind.
when parking on a hill, turn wheels away from kerb full
lock. (if facing up), or towards kurb full-lock (if going down)

I was always told NEVER to leave a vehicle with power steering on full lock when parked ??

Regards.
Automatic gearboxes - Rebecca {P}
think so - well I always do.

When else would you use it? (apart from preventing brake light dazzle)
Automatic gearboxes - edisdead {P}
www.howstuffworks.com/automatic-transmission5.htm
Did you get all that? ;-)

Certainly if I'm parked on a hill, I prefer to rely on the combined effect of handbrake and parking lock, instead of putting *all* the stress on the box.

Ed
Automatic gearboxes - Mark (RLBS)
I've driven only automatics for pretty much 20 years.

On the flat it gets no parking brake. On a slope it does, since as edisdead says, I prefer not to rely on the 'box only.
Automatic gearboxes - matt35 {P}
Mark, I have also had automatics for 30 years but always use the handbrake when in Park.
No one has hit me up the back so far, but theres always tomorrow...hope I have the handbrake on to give some possible protection to the gearbox?

Matt35.
Automatic gearboxes - SjB {P}
When I drive my brother's auto, I always:

1 Stop
2 Leave foot brake on
3 Put the hand brake on
4 Put gear selector in neutral
5 Release foot brake
6 Put foot brake on
7 Move gear selector to park
8 Release foot brake

Why?
Out of mechanical sympathy to ensure that the gearbox is never left under load. The car often moves slightly during step 5. This especially applies when parked on a steep hill, and makes an audible difference to starter motor cranking speed, and resultant vibration when running.

Automatic gearboxes - SjB {P}
Footnote to the last post:

"makes an audible difference to starter motor cranking speed"

I should have added "In very cold weather"
Automatic gearboxes - No Do$h
Having just come out of an Auto I would make the following observation:

If you are hit from behind when on the handbrake, parked or otherwise, the car may move and damage will ensue. But not to your gearbox.

Not so if you are reliant on "park". A disabled friend had his converted Toyota Auto slammed from behind whilst parked outside my house, causing relatively light body damage but moving the car. The resultant damage to the "dear"box put an end to it.

I've never really understood the "Park" function except when parked on a slope, exactly like leaving a manual in gear under the same circumstances.

NEVER have I sat at a junction in Park. Neutral, with hand well away from the lever to prevent accidental engagement in the event of an impact, combined with Handbrake.

N D
Automatic gearboxes - Dynamic Dave
On a similar note it's best to only engage park when you've "parked" up the vehicle. Leaving the engine running whilst in park for any length of time can damage the gearbox by overheating it.
Automatic gearboxes - frostbite
No-one owning up to being as sloppy as me?

I will admit to additionally using the handbrake if parked on a steep slope.
Automatic gearboxes - Martin Devon
No-one owning up to being as sloppy as me?
I will admit to additionally using the handbrake if parked on
a steep slope.

If I had frostbite I might be a little sloppy!

Regards.
Automatic gearboxes - Dizzy {P}
On a similar note it's best to only engage park when you've "parked" up the vehicle. Leaving the engine running whilst in park for any length of time can damage the gearbox by overheating it.


DD,

I believe I'm right in saying that the Park function is purely mechanical and the hydraulic circuits in Neutral and Park are identical except that, when Park is engaged with the engine running, fluid pressure is applied to a brake band solenoid to hold the pinion carrier stationary.

I could understand the fluid measurably warming if the car was left in Park with the engine running for a very long time but I don't believe the gearbox could be overheated to the point of damage in other than very extreme circumstances. I have certainly seen no warning of this in owner's handbooks in the various automatics I have owned and driven over the past 30+ years.

I personally always use Park on the flat or very gentle slopes and supplement this with the handbrake on more severe slopes. At level crossings, etc., I select Neutral and apply the handbrake as it is then a simple matter to nudge into Drive when the time comes to move off. This occasional use of the handbrake also helps keep it in working order.
Automatic gearboxes - lauriew
When "park" is selected, a steel peg locks the output shaft indirectly to the gearbox case.This is why you must only select "P" when vehicle at rest.
Automatic gearboxes - Dynamic Dave
Dizzy,

I'm only going on advice the Vaux dealer gave me. They mentioned something about the hydraulic circuit in Park being different than when other selections are used.

I must admit to being one of those people that keeps their foot on the brake at traffic lights - only because the gearbox drops itself into neutral electronically.

I still use the handbrake when I've parked up though - whether on the flat or slopes. I don't want to get out of the habit of using the handbrake as I still drive with manual gearboxes as well, and I just know one day I'll forget to apply the handbrake if I get into the habit of not using it on a regular basis.
Automatic gearboxes - Dizzy {P}
DD,

Thanks for the explanation. I don't know enough about modern Vauxhall automatic boxes to say that the dealer is definitely wrong -- but I'll bet he is. I will try and find the facts from another source (I assume the box in question is the Japanese make whose name always escapes me!).

When selecting Park on the gearboxes that I've seen, the brake band is operated to stop the pinion carrier turning so as to let the housing-mounted parking pawl engage a tooth on the ring gear without crunching. Obviously the gearbox pump is continuing to pressurise the fluid so long as the engine is running and that will gradually warm up the fluid ... but overheat? Maybe if you left it running in Park for several hours but surely not while you are sitting at traffic lights or level crossings.

Getting back to Dave H's original question, the Park mechanism is extremely strong and very reliable so I don't think it is *essential* to use the handbrake as well but, like DD says, it's undeniably good practice to do so.
Automatic gearboxes - Dynamic Dave
I assume the box in question is the Japanese make whose name
always escapes me.


The one in my old Cavalier was manuafactured by Aisin AW Co, Ltd, and was the AF 20. No idea about the Vectra. However the dealer mentioned the same thing about both cars - not to leave in park with the engine running for too long. It's the gearbox with the dipstick, as opposed to the one they fit in the Omega that hasn't got a dipstick to check the oil level.
Maybe if you left it running in Park for several hours but
surely not while you are sitting at traffic lights or level
crossings.


True, it probably won't overheat in that instance, but I'm very lazy and can't be bothered to drop it in park all the time. To get it out of park again you have to engage the foot brake to release the gearstick lock. I'd sooner leave it in neutral with the handbrake on and then drop it into drive when I need to move away again. [1] If I'm feeling in an even lazier mood, I'll sit there with my foot on the brake and leave it in "D", as I mentioned earlier - the box drops itself into "N" after a couple of seconds, and then back into "D" once your foot is off the brake pedal.

[1] I know you're supposed to press the brake pedal before shifting the gearstick, but I gather this is only taught so that you're in full control of the vehicle, and to stop it moving unintentionally forward - which is what I want it to do anyway!
Automatic gearboxes - Dynamic Dave
to stop it moving unintentionally forward - which is what I
want it to do anyway!


That came out wrong. I want to intentionally move forward. Oh you know what I mean.

 

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