Neutral Safety Switch Continuity - Torqueflight 904

[RAGNAR]

Just a quick one.

Currently I can only start in neutral, not park. I have tested continuity across the switch to the transmission casing and I get continuity on the centre pin in neutral, but not park and also continuity across the outer pins. My reverse lights also come on when I'm in reverse. Is my safety switch knackered, or is there some adjustment to be done somewhere?

Many Thanks!

[Dave999]

i have never had an auto so i don't know

but either that's how it is supposed to be or, and this is a guess, switch in upside down?

but on basic and simple clue is in the name.... neutral safety switch

if you start it in park and rev it won't you bust the park functionality in the trans? i imagine input or output shaft is locked in some way or 2 sets of gears are meshed in a way to act like a extra hand brake. so sticking a load of torque through it from the motor would be a thing to avoid...it has nowhere to go but into bending something further than it ever should be bent

if its in neutral and you start and rev it you go nowhere, which is the aim.... hence only start in neutral and be safe


if its in 1st 2nd or reverse and you start and rev it you go out of one end of the garage or the other at speed and without warning and potentially without thinking to remove a wall or open the door before you do it


hence neutral----safety---switch

but never having ever owned anything automatic i could be talking tosh.. i often do.....

switch is just a press switch that gets pressed by a lump on something that moves in the trans. simple and unlikely to go wrong unless you Bananarama! on something i'd guess



dave

[mygasser]

They should work in park and neutral. When in park the box is also in neutral so can be revved without issues.
You've never had an auto Dave, wow
Neil.

[ScottyDave]

You've never had an auto Dave, wow
Neil.

My thoughts as well

[Super Sloth]

if you start it in park and rev it won't you bust the park functionality in the trans?

"park" is just a pin that locks the output shaft at certain points so the car can't go anywhere. I've heard of the pins being sheared by folk just slamming the shifter into park before coming to a complete stop. No harm will come to the 'box by revving the engine. I suppose if you rev it to the moon and dump the shifter into drive you can flash stall the converter which isn't good.
I've been in a car when someone has thrown a car into park whilst it's still moving and the sound is much like you hear when you have a playing card on bicycle wheel spokes until the pin finally finds it's home and the drive train locks up.

There's plenty of storys out there where people have tried to be clever and bypassed these switches, started engines and vehicles have driven off 4 post lifts and that sort of thing. It's the same effect as turning the engine over in a manual car with the clutch up and first gear engaged - it moves.

[Dave999]

see told you i can talk tosh...

brings me back to is the switch in the right way round? i.e is the bit that gets pressed offset or wider on 1 side then the other?

stick has two positions and whatever presses the switch isn't pressing it in park

but you knew that

right its breakfast time..... post up when you discover what it is...


i have got an auto just remebered

got one of these on my goped

[Matt74]

I thought Dunc mentioned on another thread not leave the engine running whilst in park?

I've tried to find the thread but can't.

[db]

Yes, he said there's a bearing that fluid doesn't flow around when it's in park so it wears out.

My trans sometimes won't start in park but it's always fine in neutral.
Usually it's when I'm parked outside my ex's house. random!

[Pete]

I thought Dunc mentioned on another thread not leave the engine running whilst in park?

I've tried to find the thread but can't.

I think this is correct as it affects the fluid circulation to bearing surfaces. I always us "N".

I think there are 2 different styles of neutrals switch, and there are 2 different styles of quadrant in the transmission and they are not interchangeable....

[Dave999]

that'll explain it

wrong switch.....yay!

Dave

[RAGNAR]

The switch just screws in, so there's no real way you can fit it the wrong way round! I guess you could put the connector on the other way round, but as the two outer pins only connect the reverse lights, I'm not sure it would really matter anyway.

[John]

Whenever I've had this problem its been down to adjustment of the shifter linkage

[MattH]

I've had the "starting in drive" issue with my 904 in the Challenger, on the way to Le Mans
Started it up and then after a nanosecond once the torque convertor started doing its thing the car suddenly lurches forward towards the 69 Mustang in front of me.
Luckily lightning quick reactions saved an embarrassing collision. I now always start the car with my foot on the footbrake.