bestbooties:
On many of these modern AMT’s, (Automated manual transmissions), there are no synchro cones as a means of saving weight? but the computer controlling the 'box gets the revs JUST right to make every change smooth and silent, including the burst of revs on a changedown.
Examples like I shift use the constant mesh idea simply because it is better and produces better quality,faster,shifts wether automated or not.On the ( correct ) basis that synchros in heavy truck transmissions are just a pointless obstruction and hindrance and added reliability issue,not a help.
I’ve DDC’d ever since I first stepped into a ‘puddle jumper’ back in 84 (learnt to drive in an old Merc 307D, before that, tutored by the old man) and right up until (mainly) 2 weeks ago when my old manual Scania (and never had any part of clutch or gearbox changed) got the heave-ho for one of these modern auto box contraptions! I still give a blip of the throttle in my 2.2 diesel Mondeo (and every car I’ve ever driven) makes for a much smoother & faster downshift when time is of the essence! And talking about just dumping the clutch during a downshift, what about these ones that approach a junction/lights/roundabout and push the clutch in and let it ‘coast’ for ages…then select the wrong gear and off they scoot, red lining it at almost 30mph!
Conor:
And when you’re stuck in 3 miles of 4 lanes of nothing moving anywhere fast as the entire motorway is funnelled off the next exit and down backroads you’ll be damned glad you have an auto box. I miss having a manual gearbox so much on my truck I’m contemplating getting an automatic for my next car.
At which point if you do decide to buy that auto car be prepared to have to give it away when the time comes to fix it.Or to flog it.Either to someone who intends to break it, or convert it to manual.Bearing in mind that the latter is often now just as uneconomic as trying to fix it because of all the bs over complicated engine and transmission management interfacing.
All that just to save a bit of use of leg/foot and arm/hand.
Well my wife has just sold her automatic 1995 Mitsubishi FTO with 280,000km/175,000 miles on the clock and the autobox never gave any problem at all in the 8 years she owned it and when we did the gearbox test for the new buyer the stall revs were bang in the middle of the range they should’ve been both in drive and reverse. All we did was change the fluid and filter as recommended. If you look after them they will go forever. Most automatic gearboxes don’t actually fail from a mechanical issue rather its a lack of pressure due to the fact the filter never got changed. Change the filter, change the oil and they’re good to go again.
I just bought an automatic car. Ford tell me that the six speed gearbox, which works in a similar way to the truck gearboxes, should be good for at least ten years or 150,000 miles. For a video with some cool exploded drawings, see here: youtube.com/watch?v=K7Q2M2K0V5k
As for Double clutching - I was told not to do it way back in the 60s. I have no idea why not and carried on doing it until I got an auto. The only time I did it in a car was in the Hillman Minx that I learned to drive in. That had syncro on the two top gears but not in first, so DDC was an essential skill.
Santa…is that the Powershift? I’ve heard some bad things about that box and that’s from a ‘overheard’ conversation between 2 service techs when I had mine in for service… Maybe model dependant though as the 3 mentioned were all the same and apparently, it’s a common, known problem/issue
I know someone who drives an 11 plate VW transporter with DSG auto box. Is that what VW call it. Spoke to him yesterday. Has 226,000 miles on the clock and never had a problem with it.
tortoise:
I know someone who drives an 11 plate VW transporter with DSG auto box. Is that what VW call it. Spoke to him yesterday. Has 226,000 miles on the clock and never had a problem with it.
Yes it is Dual Shift Gearbox. It has 2 clutches so the next gear required is already engaged. Gearchanges are faster and the driver does not have to lift off the throttle during gearchanges. Porsche pioneered it and F1 cars have had them for a few years now. VW did have major problems with premature failures caused by original factory filled synthetic oil but have got it sorted now.
Actrosman:
Santa…is that the Powershift? I’ve heard some bad things about that box and that’s from a ‘overheard’ conversation between 2 service techs when I had mine in for service… Maybe model dependant though as the 3 mentioned were all the same and apparently, it’s a common, known problem/issue
That’s the one. Changes are even smoother than the ‘wet’ box on my last car. I have seen reports of problems but they seem to be on the Fiesta’s rather than the Mondeo I have - I certainly hope so. Time will tell I guess.
Santa… That’s ok then! The Techies were mumbling about ‘the mother board’ or some control chip on ‘another S Max coming in under warranty’…only good for 5 years allegedly. Is that a new shape Mondy you have? Think I’ll keep my old Sport for a bit longer and see if they release an RS/ST version of it…dreading telling 'er indoors though that we might not be having any holidays for a few years!
tortoise:
I know someone who drives an 11 plate VW transporter with DSG auto box. Is that what VW call it. Spoke to him yesterday. Has 226,000 miles on the clock and never had a problem with it.
Yes it is Dual Shift Gearbox. It has 2 clutches so the next gear required is already engaged. Gearchanges are faster and the driver does not have to lift off the throttle during gearchanges. Porsche pioneered it and F1 cars have had them for a few years now. VW did have major problems with premature failures caused by original factory filled synthetic oil but have got it sorted now.
I’m from the truck driver generation that never encountered crash boxes so double declutching has never been needed. However, some old worn gearboxes have a few gears that just will not go in on up or down shift without a horrific grind, it tends to only be 12 speed Scanias i’ve found with this problem so far, 4 series and R series and it’s usually 3rd. Double clutching seems to allow you to change gear without the grind, often it only happens when the gearbox is cold, after 20mins you can shift normally with just one clutch movement but some you have to double clutch all day. In terms of damage i’m no expert but i’m sure more damage is done during that horrible grind than by double clutching it.
