Bump starting an automatic

Top Dog

Ok - I know it won't actually work.

My real question is - can/does it do much damage to the transmission if someone is dumb enough to actually try it?

Thinking of installing a remote kill switch on the starter circuit on an automatic so that ignition would still come on as normal when the key is turned, but the starter circut wouldn't actually work unless this switch was on. Just wondering if someone swiped the keys, hopped in, couldn't get the starter to turn so rolled it down a hill to try bump it - would it do any damage?

Oh and before someone suggests installing it on the fuel pump circuit, I've already considered that. Diesel relies on the fuel for lubrication so could do damage if someone was swinging off the starter and no fuel is being delivered.

No auto box lubrication when they're in neutral I think is the biggest issue.

Tropheus

I didn't think it was possible as there isn't really a "neutral". I'm open to correction.

puzzle factory

i tried it before,impossible to bump an automatic.

Top Dog

RoverJames wrote: »

No auto box lubrication when they're in neutral I think is the biggest issue.

Must check the manual actually - I thought automatics could be towed for a limited distance on their wheels

ksimpson wrote: »

I didn't think it was possible as there isn't really a "neutral". I'm open to correction.

puzzle factory wrote: »

i tried it before,impossible to bump an automatic.

I know guys - I'm not asking about it being possible to bump start.

Rovi

It's possible with some (very) old transmissions that have a secondary hydraulic pump mounted at the rear; you need to be doing over 30mph in N before slipping it into D.
Some Borg Warner, Powerglide, and Turbo-Hydramatic auto-boxes from the 1950's were of this type.

Joe 90

Rovi wrote: »

It's possible with some (very) old transmissions that have a secondary hydraulic pump mounted at the rear; you need to be doing over 30mph in N before slipping it into D.
Some Borg Warner, Powerglide, and Turbo-Hydramatic auto-boxes from the 1950's were of this type.

Yes, I remember it was do-able with some of the older autos. I wouldn't be brave enough to try it with any of the modern stuff though, I would expect an expensive nightmare.

Weylin

joe 90.
is the cranbrook bar still there?
the black horse.and the penthouse club.
just wondering.....long time gone i reckon.

Alanstrainor

Weylin wrote: »

joe 90.
is the cranbrook bar still there?
the black horse.and the penthouse club.
just wondering.....long time gone i reckon.

Send a PM man.

jimmyw

ksimpson wrote: »

I didn't think it was possible as there isn't really a "neutral". I'm open to correction.

All autos have a neutral, dont they?

Top Dog wrote: »

Ok - I know it won't actually work.

My real question is - can/does it do much damage to the transmission if someone is dumb enough to actually try it?

Thinking of installing a remote kill switch on the starter circuit on an automatic so that ignition would still come on as normal when the key is turned, but the starter circut wouldn't actually work unless this switch was on. Just wondering if someone swiped the keys, hopped in, couldn't get the starter to turn so rolled it down a hill to try bump it - would it do any damage?

But what would the point of such a switch be then, as you dont need the starter to bump start it? if it were possible.

Top Dog wrote: »

Must check the manual actually - I thought automatics could be towed for a limited distance on their wheels ;)

They used to be able to be towed not more than 30m/k and not over 30 m/k. Modern c.. I mean stuff could be different.

Top Dog

jimmyw wrote: »

But what would the point of such a switch be then, as you dont need the starter to bump start it? if it were possible

The point is, if someone breaks into the house to get the keys, they hop in the car and turn on the ignition, starter doesn't work so they roll it down the hill hoping to bump it, cant get it started so abandon it and flee.

As far as I'm aware on modern(ish) automatics you can't bump start them. Not everyone is aware of this so some may be dumb enough to still try it.

And yeah - handbook confirms that when necessary it can be towed on its wheels for no more than 50km and no faster than 50km/h

jimmyw

Oh so its 50 now.

Yeah but most scumbags who steal cars, would be able to start it if it was in neutral or park but might not be able to move it from those positions into drive, or even able to move the car anyway.

Top Dog

jimmyw wrote: »

Oh so its 50 now.

Tis for this one anyway. But being a selectable 4wd might make a difference in this case.

jimmyw wrote: »

Yeah but most scumbags who steal cars, would be able to start it if it was in neutral or park but might not be able to move it from those positions into drive, or even able to move the car anyway.

I don't follow If they had the keys why wouldn't they be able to move it into drive?

Big Nasty

Not really understanding the point of this thread.............

jimmyw

is there not a button you have to press to move from certain positions?

I am meaning they might not be bright enough to drive an auto:D

jimmyw

jimmyw wrote: »

is there not a button you have to press to move from certain positions?

I am meaning they might not be bright enough to drive an auto:D

........... most "scumbags" stealing cars have fairly decent mechanical smarts.

Top Dog

MCMLXXV wrote: »

Not really understanding the point of this thread.............

Kinda answered my own question by checking the owners manual

jimmyw wrote: »

is there not a button you have to press to move from certain positions?

Yup. But once foot is on the brake pedal the button can be pressed and the lever will shift between positions.

jimmyw

Brake pedal and button ? you do know that men cant multitask .

Dont know about that:P

Tropheus

I'll try and sumarise. A modern(ish) auto box has an "N", but it's not that same as an "N" on a manual.

Unless the car is from the 50s or 60s (at a push - apologies for the pun), you can't bump start it.

Please lock this.

ksimpson

ksimpson wrote: »

I'll try and sumarise. A modern(ish) auto box has an "N", but it's not that same as an "N" on a manual.

Unless the car is from the 50s or 60s (at a push - apologies for the pun), you can't bump start it.

Please lock this.

Why lock it ?
funny how yesterday you were open to correction but now you seem an authority on autoboxes :pac:

dgt

w126's can be bump started and its in the manual how to do it. Push to about 18mph then into D

Tropheus

RoverJames wrote: »

Why lock it ?
funny how yesterday you were open to correction but now you seem an authority on autoboxes :pac:

Yep was open, but not corrected from what I can see.:D

Esel

Top Dog wrote: »

The point is, if someone breaks into the house to get the keys, they hop in the car and turn on the ignition, starter doesn't work so they roll it down the hill hoping to bump it, cant get it started so abandon it and flee.

Nah, they come back to your gaff, boil the kettle and then persuade you to tell them where the switch is......

Top Dog

Esel wrote: »

Nah, they come back to your gaff, boil the kettle and then persuade you to tell them where the switch is......

Hmmm :eek:

I was thinking more along the lines of them coming back, me telling them the starter is screwed, and them leaving.

Mind you, in my fantasy world the dogs would have gone nuts and woken me anyway, so while the lads are rolling down the hill I'm already on the phone to the cops.

Yes, it is nice in my fantasy world :pac: