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[tunnie]

what stops autos rolling back on hills? I know there is a limit, and they cannot hold it to a certain point.

Is it the idle throttle pushing against it?

Reason i ask, would a greased throttle cable be likely to cause an auto to roll back on a small hill?

[dad1uk]

I thought it was down to the oil pressure in the box created by the speed of the tickover. If the tickover is too slow then the car will roll back. I assume this is why most auto's I have driven always had a slightly faster tickover than the manual.

[Andy B]

what stops autos rolling back on hills? I know there is a limit, and they cannot hold it to a certain point.

Is it the idle throttle pushing against it?

Reason i ask, would a greased throttle cable be likely to cause an auto to roll back on a small hill?

You're still stirring the fluid in the gearbx when your car is in D even though you're stopped. On the level there's still enough drive to push your car forward, on a hill gravity is stronger than the drive of your gearbox. Much the same as if it was you pushing your car ... easier on the level but harder going up hill.  

Your 2.2 is DBW isn't it?  :-/

[TheBoy]

drag on gearbox.

Check fluid level.

[Taxi_Driver]

what stops autos rolling back on hills? I know there is a limit, and they cannot hold it to a certain point.

Is it the idle throttle pushing against it?

Reason i ask, would a greased throttle cable be likely to cause an auto to roll back on a small hill?

I agree with the others.......depends what you mean small hill??

If you take 2 autos the same and one rolls back, the other holds or even creeps forward slightly.....it would suggest to me the torque convertor in the one that rolls back is donald.  

There is a 'stall' test you can do with autos.
Handbrake on, foot on brake, select D and floor the go pedal.....for no more than about 5 secs to see what the revs go to.....do the same in another 'the same' car for comparision......If one revs quite a bit higher than the other........its a sure sign of a donald torque convertor.

Note: The no more than about 5 secs is fairly important....do it for longer and you will donald the torque convertor.....it will overheat!

[tunnie]

this is mother tunnies 3.0 Estate, i took it to the section were she said it rolled back, i could not replicate it.

Might top up the fluid tomorrow to be sure  

[TheBoy]

this is mother tunnies 3.0 Estate, i took it to the section were she said it rolled back, i could not replicate it.

Might top up the fluid tomorrow to be sure  

Probably worth changing fluid, as you don't know history.

[VXL V6]

what stops autos rolling back on hills? I know there is a limit, and they cannot hold it to a certain point.

Is it the idle throttle pushing against it?

Reason i ask, would a greased throttle cable be likely to cause an auto to roll back on a small hill?

I agree with the others.......depends what you mean small hill??

If you take 2 autos the same and one rolls back, the other holds or even creeps forward slightly.....it would suggest to me the torque convertor in the one that rolls back is donald.  

There is a 'stall' test you can do with autos.
Handbrake on, foot on brake, select D and floor the go pedal.....for no more than about 5 secs to see what the revs go to.....do the same in another 'the same' car for comparision......If one revs quite a bit higher than the other........its a sure sign of a donald torque convertor.

Note: The no more than about 5 secs is fairly important....do it for longer and you will donald the torque convertor.....it will overheat!

Can you do that with the DBW cars? I thought that if the brakes are engaged then the throttle will not operate on the DBW setup.  :-/

[Kevin Wood]

DBW cars seem to let you do it for a few seconds, then go back to idle. Discovered this when "conditioning" my new brake disks.

Kevin

[theolodian]

this is mother tunnies 3.0 Estate, i took it to the section were she said it rolled back, i could not replicate it.

Might top up the fluid tomorrow to be sure  

Probably worth changing fluid, as you don't know history.

I'm pretty sure of the history on mine, 170K.  

[TheBoy]

this is mother tunnies 3.0 Estate, i took it to the section were she said it rolled back, i could not replicate it.

Might top up the fluid tomorrow to be sure  

Probably worth changing fluid, as you don't know history.

I'm pretty sure of the history on mine, 170K.  

Changed mine at 150k, don't think it had been done before. Fluid looked OK - dark but not that burnt brown. Changing the fluid mad a subtle improvement to the box, feeling more solid, so I'd say its worth doing

[theolodian]

this is mother tunnies 3.0 Estate, i took it to the section were she said it rolled back, i could not replicate it.

Might top up the fluid tomorrow to be sure  

Probably worth changing fluid, as you don't know history.

I'm pretty sure of the history on mine, 170K.  

Changed mine at 150k, don't think it had been done before. Fluid looked OK - dark but not that burnt brown. Changing the fluid mad a subtle improvement to the box, feeling more solid, so I'd say its worth doing

Tried to have 2 places do it last year, both refused.  

[Lizzie_Zoom]

this is mother tunnies 3.0 Estate, i took it to the section were she said it rolled back, i could not replicate it.

Might top up the fluid tomorrow to be sure  

Probably worth changing fluid, as you don't know history.

I'm pretty sure of the history on mine, 170K.  

Changed mine at 150k, don't think it had been done before. Fluid looked OK - dark but not that burnt brown. Changing the fluid mad a subtle improvement to the box, feeling more solid, so I'd say its worth doing

Tried to have 2 places do it last year, both refused.  

Why would they do that?  Were they Vx dealers? :-? :-? :-?

[tunnie]

this is mother tunnies 3.0 Estate, i took it to the section were she said it rolled back, i could not replicate it.

Might top up the fluid tomorrow to be sure  

Probably worth changing fluid, as you don't know history.

I'm pretty sure of the history on mine, 170K.  

Changed mine at 150k, don't think it had been done before. Fluid looked OK - dark but not that burnt brown. Changing the fluid mad a subtle improvement to the box, feeling more solid, so I'd say its worth doing

Tried to have 2 places do it last year, both refused.  

Why would they do that?  Were they Vx dealers? :-? :-? :-?

Its a doddle!! Nothing complicated about it what so ever.

[Phil B]

DBW cars seem to let you do it for a few seconds, then go back to idle. Discovered this when "conditioning" my new brake disks.

Kevin

No burnouts then!