Omega Owners Forum

Chat Area => General Car Chat => Topic started by: Shackeng on 20 February 2017, 11:02:43

Title: Auto question
Post by: Shackeng on 20 February 2017, 11:02:43
My daughter claims that both her autos, Forester and Ranger crewcab truck, if on a steep slope, in gear with engine running, for example at traffic lights on a hill, do not roll either forward (or back), and require no brake or accelerator to hold them. Now either modern auto boxes have a sensor to lock the torque converter, or there is something wrong with both my Omegas. I suspect she is wrong, and has got used to holding them on the brakes, but please confirm.  :o
Title: Re: Auto question
Post by: steve6367 on 20 February 2017, 11:05:15
My daughter claims that both her autos, Forester and Ranger crewcab truck, if on a steep slope, in gear with engine running, for example at traffic lights on a hill, do not roll either forward (or back), and require no brake or accelerator to hold them. Now either modern auto boxes have a sensor to lock the torque converter, or there is something wrong with both my Omegas. I suspect she is wrong, and has got used to holding them on the brakes, but please confirm.  :o

Depends on the slope, my 3 either creep forward, hold nicely or gently move backwards. There are 2 sets of lights near me where all is balanced and it will hold itself, although I normally put the hand brake on anyway.
Title: Re: Auto question
Post by: Shackeng on 20 February 2017, 11:07:30
My daughter claims that both her autos, Forester and Ranger crewcab truck, if on a steep slope, in gear with engine running, for example at traffic lights on a hill, do not roll either forward (or back), and require no brake or accelerator to hold them. Now either modern auto boxes have a sensor to lock the torque converter, or there is something wrong with both my Omegas. I suspect she is wrong, and has got used to holding them on the brakes, but please confirm.  :o

Depends on the slope, my 3 either creep forward, hold nicely or gently move backwards. There are 2 sets of lights near me where all is balanced and it will hold itself, although I normally put the hand brake on anyway.

Agreed, and why I said steep. :y
Title: Re: Auto question
Post by: aaronjb on 20 February 2017, 11:18:39
They probably have "hill hold assist" (like a lot, if not all, modern autos and semi autos) - on a vehicle with electric handbrake it'll put the handbrake on automatically when you come to a stop on the footbrake, and then release it as soon as you tickle the throttle, with a manual handbrake there is a valve to maintain pressure in the line to the rear brakes.

In fact, my manual Ranger (64 plate) used to do exactly the same though it would release after a set amount of time even if you weren't moving; it was basically there to keep you still until you put the handbrake on.
Title: Re: Auto question
Post by: Shackeng on 20 February 2017, 11:25:04
They probably have "hill hold assist" (like a lot, if not all, modern autos and semi autos) - on a vehicle with electric handbrake it'll put the handbrake on automatically when you come to a stop on the footbrake, and then release it as soon as you tickle the throttle, with a manual handbrake there is a valve to maintain pressure in the line to the rear brakes.

In fact, my manual Ranger (64 plate) used to do exactly the same though it would release after a set amount of time even if you weren't moving; it was basically there to keep you still until you put the handbrake on.

Thanks Aaron, we live and learn, I guess thats why she was caught out yesterday driving an auto hire vehicle here in Grenada. Complained like mad because she had to keep juggling with a foot operated handbrake when trying to set off in reverse up a steep slope. :y Its a girlie thing. :-X
Title: Re: Auto question
Post by: Marks DTM Calib on 20 February 2017, 11:39:07
Its actually done by the ABS module, Hill start assist detects the angle and applies the wheel brakes for a period of time.......after 10 seconds or so it does release so......hence easy to test!
Title: Re: Auto question
Post by: Andy B on 20 February 2017, 11:54:08
.... and applies the wheel brakes for a period of time.......after 10 seconds or so it does release so......hence easy to test!

That depends on the vehicle. Newer Mercs tend to have 'hold', which holds the brakes on forever & a day or till you touch the throttle (I've  only driven one like that) & Mercs SBC brakes apparently used to do the same. My R Class though, just holds the brakes on for 'a short time' when on a hill .... I've  not noticed it do it otherwise. My Smart Roadster holds the brakes on for 0.7secs ..... who decided that?
I just use my left foot  ;) which will confuse the cars sometimes.
Title: Re: Auto question
Post by: Shackeng on 20 February 2017, 11:58:18
.... and applies the wheel brakes for a period of time.......after 10 seconds or so it does release so......hence easy to test!

That depends on the vehicle. Newer Mercs tend to have 'hold', which holds the brakes on forever & a day or till you touch the throttle (I've  only driven one like that) & Mercs SBC brakes apparently used to do the same. My R Class though, just holds the brakes on for 'a short time' when on a hill .... I've  not noticed it do it otherwise. My Smart Roadster holds the brakes on for 0.7secs ..... who decided that?
I just use my left foot ;) which will confuse the cars sometimes.

Exactly. :y
Title: Re: Auto question
Post by: Field Marshal Dr. Opti on 20 February 2017, 12:21:33
They probably have "hill hold assist" (like a lot, if not all, modern autos and semi autos) - on a vehicle with electric handbrake it'll put the handbrake on automatically when you come to a stop on the footbrake, and then release it as soon as you tickle the throttle, with a manual handbrake there is a valve to maintain pressure in the line to the rear brakes.

In fact, my manual Ranger (64 plate) used to do exactly the same though it would release after a set amount of time even if you weren't moving; it was basically there to keep you still until you put the handbrake on.

My XFR has one of these. Even now I'm not really sure what to do with it. Even on steep slopes I never need to apply it.
Title: Re: Auto question
Post by: aaronjb on 20 February 2017, 12:54:27
Its actually done by the ABS module, Hill start assist detects the angle and applies the wheel brakes for a period of time.......after 10 seconds or so it does release so......hence easy to test!

The Skoda doesn't release (ever) on a hill - though you might still be right about it being the ABS rather than electric handbrake as if you switch the ignition off there is a very definite 'release' on to the handbrake now that I think about it (back end rises up slightly).
Title: Re: Auto question
Post by: Kevin Wood on 20 February 2017, 13:03:49
Do these newfangled cars have a "just let me drive the effing thing!" button? ::)
Title: Re: Auto question
Post by: X30XE on 20 February 2017, 14:26:11
AR35 is by far the worst behaved autobox in my experience. Volvo/BMW/Mercedes/Modern Jaguar/ford all buy better boxes.  Unless we're talking a 1:3 gradient I would expect any of my autos to sit still (or preferably creep slightly) until they're told to do otherwise. 
Title: Re: Auto question
Post by: Kevin Wood on 20 February 2017, 14:52:54
Whether an auto box holds on a hill actually has nothing to do with how good the box is!

The box is sitting there with 1st gear engaged waiting for you to drive off, just as a manual gearbox would be in the same situation. The reason that there is any creep or "holding" capability on a hill is because there is some torque coupling through the torque converter to the input of the auto box at idle speed. Unlike a clutch, a torque converter cannot completely disengage. If it happens that enough torque is transferred to hold you on the hill it's an unintended side-effect of how your torque converter works, not a driver aid or a sure sign that you have a "better" gearbox. Go to another hill and you might be creeping forwards or rolling back because the torque converter doesn't "know" how steep the hill is.

Another car will have different weight, rolling friction, idle speed, torque converter characteristics and 1st gear ratio, so it would be very unlikely to behave the same way.
Title: Re: Auto question
Post by: Doctor Gollum on 20 February 2017, 16:48:24
Do these newfangled cars have a "just let me drive the effing thing!" button? ::)
Yes, but it's about fifteen layers down in a random sub menu which apparently also controls the amount of time the boot light remains on after closing and what temperature you wish the passenger front door ashtray to maintain ;)
Title: Re: Auto question
Post by: aaronjb on 20 February 2017, 16:51:05
Do these newfangled cars have a "just let me drive the effing thing!" button? ::)
Yes, but it's about fifteen layers down in a random sub menu which apparently also controls the amount of time the boot light remains on after closing and what temperature you wish the passenger front door ashtray to maintain ;)

Don't be silly.




New cars don't come with an ashtray!  :P ;D

(No, really, optional extra on the Skoda, as standard you get a storage cubby)
Title: Re: Auto question
Post by: Kevin Wood on 20 February 2017, 16:53:22
Do these newfangled cars have a "just let me drive the effing thing!" button? ::)
Yes, but it's about fifteen layers down in a random sub menu which apparently also controls the amount of time the boot light remains on after closing and what temperature you wish the passenger front door ashtray to maintain ;)
So it's about as much fun as the rather windows machine I have to use every day, then? ::)

They will prise the keys to my kit car out of my rigor mortised fingers!
Title: Re: Auto question
Post by: Doctor Gollum on 20 February 2017, 16:55:33
Do these newfangled cars have a "just let me drive the effing thing!" button? ::)
Yes, but it's about fifteen layers down in a random sub menu which apparently also controls the amount of time the boot light remains on after closing and what temperature you wish the passenger front door ashtray to maintain ;)
So if the firstowner didn't specify the Smoker Pack, then Kevin won't get his button... Of course if it isn't fitted with the £3,000 tft sat nav display, sorry user interface, then he will only get the radio presets anyway...

Don't be silly.




New cars don't come with an ashtray!  :P ;D

(No, really, optional extra on the Skoda, as standard you get a storage cubby)
Title: Re: Auto question
Post by: Kevin Wood on 20 February 2017, 17:00:35
Darn! Forgot to steal the smoker pack out of my hired Hyundai in South Africa. (ashtray that fits in cup holder).

The MIL's new i10 self-perambulating ashtray will probably need emptying soon.
Title: Re: Auto question
Post by: X30XE on 20 February 2017, 18:29:21
Whether an auto box holds on a hill actually has nothing to do with how good the box is!

The box is sitting there with 1st gear engaged waiting for you to drive off, just as a manual gearbox would be in the same situation. The reason that there is any creep or "holding" capability on a hill is because there is some torque coupling through the torque converter to the input of the auto box at idle speed. Unlike a clutch, a torque converter cannot completely disengage. If it happens that enough torque is transferred to hold you on the hill it's an unintended side-effect of how your torque converter works, not a driver aid or a sure sign that you have a "better" gearbox. Go to another hill and you might be creeping forwards or rolling back because the torque converter doesn't "know" how steep the hill is.

Another car will have different weight, rolling friction, idle speed, torque converter characteristics and 1st gear ratio, so it would be very unlikely to behave the same way.

Alright Mr Pedant  ::) xyz cars all have torque converters that actually transfer energy from the engine to the gearbox unlike every AR35 I've ever driven which just heats fluid below lock up speed. ;)
Title: Re: Auto question
Post by: TheBoy on 20 February 2017, 18:49:21
The Omega auto does seem to have more slip than more modern autoboxes.  Not sure if this is because its a 30yr old design, or because virtually all of them have well over 100k on them, and are all 14yrs old.

I suspect a bit of both, though I do recall other autos in the 1990s needed an awful lot of throttle to get them rolling...
Title: Re: Auto question
Post by: 2boxerdogs on 20 February 2017, 18:50:11
No hills round here so don't know about the Merc.😂😂
Title: Re: Auto question
Post by: Kevin Wood on 20 February 2017, 19:16:18
The Omega auto does seem to have more slip than more modern autoboxes.  Not sure if this is because its a 30yr old design, or because virtually all of them have well over 100k on them, and are all 14yrs old.

I suspect a bit of both, though I do recall other autos in the 1990s needed an awful lot of throttle to get them rolling...

Probably because most modern auto boxes have more ratios, so can have a lower 1st gear and a lower lockup speed on the torque converter. :y
Title: Re: Auto question
Post by: Andy H on 20 February 2017, 19:16:58
The Omega auto does seem to have more slip than more modern autoboxes.  Not sure if this is because its a 30yr old design, or because virtually all of them have well over 100k on them, and are all 14yrs old.

I suspect a bit of both, though I do recall other autos in the 1990s needed an awful lot of throttle to get them rolling...
I suspect it is by design, old school 3 speed boxes needed lots of slip to bridge the gap between the ratios, the Omega has 4 ratios so doesn't need quite as much slip.

Some modern cars have 7 or 8 ratios so very little slip is required (particularly as they are bolted to diseasal engines that have no desire to get up and go and much prefer to keep bonking away at tick over munching gearboxes).
Title: Re: Auto question
Post by: STEMO on 20 February 2017, 19:46:05
Even wifey's French craptur has hill hold. Lasts about two seconds, just enough to get from brake to clutch.
Title: Re: Auto question
Post by: Andy B on 20 February 2017, 19:49:50
...., just enough to get from brake to clutch.

What's  a clutch?  ;)
Title: Re: Auto question
Post by: STEMO on 20 February 2017, 20:00:35
...., just enough to get from brake to clutch.

What's  a clutch?  ;)
Something that people who know how to drive use. If you can drive using a clutch, you get a full driving licence. If you cannot use a clutch, you get a kind of 'junior' driving licence.  :)
A bit like the diffence between a proper car and a dodgem car.  ;D
Title: Re: Auto question
Post by: Andy B on 20 February 2017, 20:21:43
If you can drive using a clutch,
I can ..... just choose not too. I can be in control with 2 pedals as I can with 3

Quote
you get a full driving licence.
Got one thanks & for a bike
Title: Re: Auto question
Post by: Shackeng on 20 February 2017, 23:02:35
There have been some interesting points made here and I have certainly learnt something. :y
Title: Re: Auto question
Post by: Lazydocker on 21 February 2017, 01:25:30
Darn! Forgot to steal the smoker pack out of my hired Hyundai in South Africa. (ashtray that fits in cup holder).

The MIL's new i10 self-perambulating ashtray will probably need emptying soon.

Do you want one? Sure I've got a couple knocking about somewhere :-\
Title: Re: Auto question
Post by: Kevin Wood on 21 February 2017, 10:33:58
Darn! Forgot to steal the smoker pack out of my hired Hyundai in South Africa. (ashtray that fits in cup holder).

The MIL's new i10 self-perambulating ashtray will probably need emptying soon.

Do you want one? Sure I've got a couple knocking about somewhere :-\
I'll double check, as she may have sorted it, but that might be handy. Thanks. :y
Title: Re: Auto question
Post by: STEMO on 21 February 2017, 15:03:04
Darn! Forgot to steal the smoker pack out of my hired Hyundai in South Africa. (ashtray that fits in cup holder).

The MIL's new i10 self-perambulating ashtray will probably need emptying soon.

Do you want one? Sure I've got a couple knocking about somewhere :-\
I took mine out of the Astra. Scumbags know that people fill them up with change for car parks etc., and will break a window to snatch it.
Title: Re: Auto question
Post by: Marks DTM Calib on 21 February 2017, 15:11:02
AR35 is by far the worst behaved autobox in my experience. Volvo/BMW/Mercedes/Modern Jaguar/ford all buy better boxes.  Unless we're talking a 1:3 gradient I would expect any of my autos to sit still (or preferably creep slightly) until they're told to do otherwise.

AR35 as was fitted to 5 series BMWs? (named the 4L30E)
Title: Re: Auto question
Post by: X30XE on 21 February 2017, 16:01:37
AR35 is by far the worst behaved autobox in my experience. Volvo/BMW/Mercedes/Modern Jaguar/ford all buy better boxes.  Unless we're talking a 1:3 gradient I would expect any of my autos to sit still (or preferably creep slightly) until they're told to do otherwise.

AR35 as was fitted to 5 series BMWs? (named the 4L30E)

Pass, quite possibly; I've never owned a 5. (although that would nicely explain why the 528i touring I drove a couple of weeks ago seemed to have torque converter slip... maybe it was just an AR35  :-\ )

Personally I much prefer the ZF 5HP in the 728i...  Or the 5G-tronic in the S class... Or walking...  ;D
Title: Re: Auto question
Post by: Doctor Gollum on 21 February 2017, 16:43:23
No noticeable slip on my 5 speed 525 box... That said I haven't driven it for nearly a week :-X

We have a tiptronic '53 Sprinter at work and the box in that is horrific... Try a standing start on a steep slope and in D it will roll back about 20' before the slop comes out of the drivetrain :D
Title: Re: Auto question
Post by: X30XE on 21 February 2017, 17:36:27
No noticeable slip on my 5 speed 525 box... That said I haven't driven it for nearly a week :-X

We have a tiptronic '53 Sprinter at work and the box in that is horrific... Try a standing start on a steep slope and in D it will roll back about 20' before the slop comes out of the drivetrain :D

What model year?
Title: Re: Auto question
Post by: Doctor Gollum on 21 February 2017, 18:11:51
'51
Title: Re: Auto question
Post by: X30XE on 21 February 2017, 18:26:54
'51

Surprise of all surprises.... ZF5HP19.   ;)
Title: Re: Auto question
Post by: Doctor Gollum on 21 February 2017, 22:24:15
Why the surprise?
Title: Re: Auto question
Post by: X30XE on 21 February 2017, 22:49:47
#sarcasm ::)

You report it doesn't slip and it transpires not to be an AR35 (by any other name). ;)
Title: Re: Auto question
Post by: Doctor Gollum on 21 February 2017, 22:51:34
#oh...

I never said it was ;D
Title: Re: Auto question
Post by: X30XE on 21 February 2017, 22:54:29
Keep up at the back Gollum  :D