Need advice (auto transmission)

Swedishmoose · 04-07-2016, 07:13 PM

Hi guys,

I tried to find information about my issue (if it is an issue) but couldn't find anything.

So i'm hoping that somebody here might have a light bulb moment.

I started our 2000 Falcon Futura in our garage this morning when it was kind of cold (5 C). The garage is levelled.

When I put the auto in reverse i moved about one meter backwards and then i put the auto back in neutral because i forgot something in the house.

The moment i put it in neutral and lift my foot of the foot brake, i noticed that the car was still creeping forward just slightly.
When I prodded the throttle the car was reacting to it even though it was in neutral.

I repeated it again but put it in drive (D) this time, rolled forward a bit, put it back in neutral and it was again creeping forward just slightly.

Could it have something to do with the thicker cold transmission fluid in the morning?
When the car had reached operating temperature, everything was fine.

The gears are definitely not engaged which would mean that the shifter linkage would need adjustment.

I also noticed when it was so cold this morning, that when i put the auto in gear the RPM didn't drop instantly from 700(N) to about 500(R, D). It was a bit inert and slowish.
Same when I put it back in neutral. Usually the RPM goes back up from 500 (in gear) to 700 (in neutral) instantly, but it was also a bit inert.

When operating temperature is reached everything is fine.

I also don't know if these two things (car slightly creeping forward in neutral when cold) and RPM adjusting very slowly when cold in neutral and in gear have something to do with each other.

Hopefully it wasn't too confusing.

Anyone an idea ????

**gregaust** · 04-07-2016, 09:27 PM

There is still a little drag in the clutch packs even with them disengaged . The slightly colder oil possibly contributing also . Nothing to worry about IMO .

Crazy Dazz · 04-07-2016, 11:13 PM

There are no gears to engage, so it won't be anything to to do with linkages. Automatics change gear by hydraulically opening and closing clutches and bands.
As Greg said, when in neutral one of the clutches is open, but there will still be some fluid drag, acting almost as a (very poor) fluid-drive. And as you correctly suspected, its exacerbated by the higher viscosity of cold fluid.
Only other thing I would ask, is when was the last time you have it serviced, or checked the fluid? (Unfortunately it s a PITA, but if it's probably never been done, it might pay to check the fluid level and condition. There's no dipstick on an AU, just a plug.)

And yes, in cold weather it will idle a little higher until it warms up a bit.

Swedishmoose · 05-07-2016, 01:19 AM

Thanks guys for the replies.

I know the transmission uses bands and clutches and oil to operate but as i am not a tranny guy i have just a basic understanding of it.
We bought the car in 2009 with 125000 km on it, did a tranny service at 140000 km and now we are sitting at 171000 km. Should be still alright although i haven't checked the fluid level ever since last service.
I also noticed when i approach a roundabout and the car is rolling slowly in whatever gear it is in at that moment just before the car stops and i want to quickly make use of a gap in roundabout traffic, i step on the accelerator, the RPM goes slightly up and then the gear engages slightly rough.
It shifts very smoothly and i never lost drive in lets say a roundabout due to low fluid.

But thanks for the info.
I would not have guessed that there is so much friction that a car could still creep forward when cold.

With regards to the idle i guess i explained it wrong.

When the car is warm, the RPM adjusts almost instantly when i move the auto lever between N and D or R.
When cold , it does it a bit lazily not that instantly.
Couldn't quite make sense of it.

meanfalcon · 05-07-2016, 07:00 AM

Hi there im not a tranny either (Ha Ha)

Keep it serviced regular. Dirty old oil stuffs up the operation of the solenoids and the filter is paper and will fail in time.

Don't worry about the idle the computer has sensors all over the place and is making certain the engine won't stall when cold. A good thing, its working.

Mike

Swedishmoose · 05-07-2016, 10:51 AM

I might add that I always put the auto in neutral at the traffic lights out of habit.

I wonder if i should leave it in drive.

some say the clutches wear out more in N so no one should put the auto tranny in N at the lights...

others say you should put it in N to relieve pressure in the auto tranny.

By the way....the car is even creeping forward in N when its cold even though i had it in reverse before putting it in neutral.

But its all good again when car is warm.

Crazy Dazz · 06-07-2016, 01:28 AM

Quote:

Originally Posted by Swedishmoose

By the way....the car is even creeping forward in N when its cold even though i had it in reverse before putting it in neutral.

Its not like a manual box, where you depress the clutch and the car stays in gear. When you shift to neutral it doesn't stay in reverse. The default is always forward.
I'm not saying it should be doing what it is, but it is explainable.
Its possible the clutch or band isn't opening far enough, so there is just enough drag when the fluid is thicker.

IIRC there are 4 clutches. One of those is engaged for all forward gears, but open in neutral, it would be this one I suspect is dragging.

Shifting to neutral at the lights is usually not recommended. It probably does no real harm, but each time you do it, you're opening and closing a clutch that doesn't need to be. Its conceivable that over many years that might add up.
You're certainly NOT straining your tranny by leaving it in drive.

The idle issue you describe, ie it is slower to drop the revs when you engage drive, could most likely be one of two things. Either the ECU is giving it a bit more juice in cold weather, or your tranny is a bit slower to load up.

I don't recall what the service interval is, but it wouldn't be a bad idea to check the level and condition of the fluid.

Swedishmoose · 06-07-2016, 08:42 AM

Thanks again for the reply.

It makes all sense and i guess i'll keep on monitoring.
It has probably done it every winter but i just found out this week when i forgot something in the house and put it in neutral and not park.

And the thicker viscosity of the tranny fluid seems to influence the tight tolerances in an auto tranny.
It is not a lot of drag because i can stop the car creeping by putting my foot on the garage floor.

And as you said, it seems to be the ECU which is injecting a richer mixture and therefore it feels all bit different to what i was used to.

Both characteristics that i have discribed vanish with incresing operating temperature and are gone when the car is warm.
Allready after idling in the garage for 3 minutes made a change.
And as i said it shifts smoothly when cold and warm.

I wish there was a dip stick because i can't be bothered to put the car on stands.

Maybe i can reach the filler plug without stands.

The fluid level is ok, when the fluid is level with the bottom of the filler hole, right?

Maybe i just worry too much.

Cheers

Mr Hardware · 07-07-2016, 01:10 PM

Quote:

Originally Posted by Swedishmoose

Maybe i just worry too much.

Speaking as kindly as I can, I do believe this to be the case.
From the threads you have started in the past I conclude that you are extremely perceptive, and as a result, it might do you well to dismiss some things for your own benefit.

I say this as kindly as possible and also as someone who gets very finicky about his own car, and has had to learn to brush off many things.

Absolute worst case scenario in all of this is that your trans will crap itself and you'll need a $1600 rebuild. Which seems bad, but that's an every day possibility in a 16 year old car.

**George V** · 07-07-2016, 07:52 PM

Swedishmoose,

Re delay in gears engaging, especially when turning before warm up, I would check fluid level with engine running / gear in P.

The rest, if these worry you then a routine filter & oil change may help.

We do find stuff to fix in our cars just because it is our "hobby".

Regards,
George V

Swedishmoose · 19-07-2016, 10:03 AM

Quote:

Originally Posted by Mr Hardware

Speaking as kindly as I can, I do believe this to be the case.
From the threads you have started in the past I conclude that you are extremely perceptive, and as a result, it might do you well to dismiss some things for your own benefit.

I say this as kindly as possible and also as someone who gets very finicky about his own car, and has had to learn to brush off many things.

Absolute worst case scenario in all of this is that your trans will crap itself and you'll need a $1600 rebuild. Which seems bad, but that's an every day possibility in a 16 year old car.

That is probably true to some extend. I might even be OCD.

On the other hand....if I can prevent an expensive rebuilt, I would prefer that of course.

In order to do so, I have to be finicky and analytical and have to gather as much information as possible and i always thought that a forum like this was especially created for these kind of issues.

I have opened up so many threads like that in the past because I couldn't find satisfactory answers in all my search efforts.

So be it.

But I thank you for replying as well and that a possible rebuilt might come to 1600 Dollar was a valuable piece of information for me which I would have asked at some stage anyways.

Cheers

The Moose