There sure as [censored] IS forcing of synchro's. See my post above.
How well will a DCT survive stop and go traffic
- Thread starter WhyMe
- Start date
- Status
And I do not double-clutch for saving fuel. Sorry, I mis-read. You did not talk about fuel-mileage; rather long service life.
The reason I double-declutch down - is that for me that butter-smooth synchro action is important to me. For a car where the 'box is NOT double-clutched down... well, most of the used cars I've bought have lost that butter-smooth action they had when they were new.
For me, I want to preserve that.
The reason I double-declutch down - is that for me that butter-smooth synchro action is important to me. For a car where the 'box is NOT double-clutched down... well, most of the used cars I've bought have lost that butter-smooth action they had when they were new.
For me, I want to preserve that.
Last edited:
Please see attached... comment re the brutally-fast nature of (internal) DSG (or DCT) shifts.
Originally Posted by KrisZ
The VW Jetta I drove with a TDC rev matched all downshifts, so it should not be a problem, but if Hyundai uses dry clutches, they are much less tolerant to heat than wet clutch setups.
If there is any lesson to be had, just look at Ford. I highly dount Hyundai made a better unit.
From what I read , the Ford dual clutch transmissions have been a disaster ! Not sure that Ford ever solved / fixed the problems . Not sure Ford is still useing them ?
The VW Jetta I drove with a TDC rev matched all downshifts, so it should not be a problem, but if Hyundai uses dry clutches, they are much less tolerant to heat than wet clutch setups.
If there is any lesson to be had, just look at Ford. I highly dount Hyundai made a better unit.
From what I read , the Ford dual clutch transmissions have been a disaster ! Not sure that Ford ever solved / fixed the problems . Not sure Ford is still useing them ?
Sure, in those rare cases when the transmission has to drop two or more gears, there will be some additional stress on the synchros, but in general driving it should not even be a worry.
Just like most people don't downshift at high RPM during normal driving conditions.
I agree with you that with these automated manual transmissions the driver has no control with how the transmission shifts, so you have to trust the engineering behind it.
Personally, having experienced their operation, my biggest worry is clutch wear, as these transmissions slip the clutch a lot during slow speed maneuvers. I guess one would have to adjust their driving style to minimize that slippage as was suggested in this thread.
Most people however don't even know how to drive a manual transmission so how would they know when the clutches are slipping excessively?
Just like most people don't downshift at high RPM during normal driving conditions.
I agree with you that with these automated manual transmissions the driver has no control with how the transmission shifts, so you have to trust the engineering behind it.
Personally, having experienced their operation, my biggest worry is clutch wear, as these transmissions slip the clutch a lot during slow speed maneuvers. I guess one would have to adjust their driving style to minimize that slippage as was suggested in this thread.
Most people however don't even know how to drive a manual transmission so how would they know when the clutches are slipping excessively?
Last edited:
Originally Posted by PimTac
Originally Posted by RayCJ
Originally Posted by Kira
What are some of those considerations/driving habits when driving a DCT?
No creeping and crawling. If you're in stop/go traffic, don't inch along slowly but rather try to move in discrete distances of at least 1 car length at a time.
BTW: the reason I purchased a Mazda3 instead of a VW TDI was because of the higher maintenance transmission in the VW. The Mazda3 has a 6 speed auto that has a lock-up torque converter. When speeds are stable, the torque converter has a clutch that locks up. When transitioning thru gears, it unlocks and lets the converter handle the transition smoothly. It has a long history of being pretty bullet-proof and needs no special maintenance.
Ray
My understanding is that the TC locks up around 5mph and the transmission is pretty much direct.
I don't know the exact details but, based on performance that could very well be true. I can say that certain conditions (when slowing down then suddenly needing to speed-up a little) I can feel a slight upward rev followed by a lockup. The sensation is very slight and doesn't happen very often at all. My gut feeling was that the TC was unlocking and locking once the computer figured-out what to do next. I could be wrong about this... Anyhow, I rate this transmission very highly in terms of performance in both "economy" and "sport" modes. The shifts happen exactly when my phantom clutch mentality thinks they should. My car does not have steering wheel paddle shifters but, the gear selector can be slap-sticked. I never bother with that because the natural operation does everything right when it's supposed to.
Ray
Originally Posted by RayCJ
Originally Posted by Kira
What are some of those considerations/driving habits when driving a DCT?
No creeping and crawling. If you're in stop/go traffic, don't inch along slowly but rather try to move in discrete distances of at least 1 car length at a time.
BTW: the reason I purchased a Mazda3 instead of a VW TDI was because of the higher maintenance transmission in the VW. The Mazda3 has a 6 speed auto that has a lock-up torque converter. When speeds are stable, the torque converter has a clutch that locks up. When transitioning thru gears, it unlocks and lets the converter handle the transition smoothly. It has a long history of being pretty bullet-proof and needs no special maintenance.
Ray
My understanding is that the TC locks up around 5mph and the transmission is pretty much direct.
I don't know the exact details but, based on performance that could very well be true. I can say that certain conditions (when slowing down then suddenly needing to speed-up a little) I can feel a slight upward rev followed by a lockup. The sensation is very slight and doesn't happen very often at all. My gut feeling was that the TC was unlocking and locking once the computer figured-out what to do next. I could be wrong about this... Anyhow, I rate this transmission very highly in terms of performance in both "economy" and "sport" modes. The shifts happen exactly when my phantom clutch mentality thinks they should. My car does not have steering wheel paddle shifters but, the gear selector can be slap-sticked. I never bother with that because the natural operation does everything right when it's supposed to.
Ray
My understanding is that DCT doesn't wear well in SnG traffic. It's akin to riding the clutch all the time, especially in rush hour traffic.
Dry clutch (ex, VW 7 spd DSG) are apparently worse for wear when compared to wet clutch. I really can't fathom why these units are in anything other than high performance cars
Dry clutch (ex, VW 7 spd DSG) are apparently worse for wear when compared to wet clutch. I really can't fathom why these units are in anything other than high performance cars
Originally Posted by BMWTurboDzl
My understanding is that DCT doesn't wear well in SnG traffic. It's akin to riding the clutch all the time, especially in rush hour traffic.
Dry clutch (ex, VW 7 spd DSG) are apparently worse for wear when compared to wet clutch. I really can't fathom why these units are in anything other than high performance cars
They have no place in non-performance cars!
My understanding is that DCT doesn't wear well in SnG traffic. It's akin to riding the clutch all the time, especially in rush hour traffic.
Dry clutch (ex, VW 7 spd DSG) are apparently worse for wear when compared to wet clutch. I really can't fathom why these units are in anything other than high performance cars
They have no place in non-performance cars!
Originally Posted by BMWTurboDzl
My understanding is that DCT doesn't wear well in SnG traffic. It's akin to riding the clutch all the time...
...I really can't fathom why these units are in anything other than high performance cars
Driven by a person who knows how to drive a manual trans the clutch wear in city traffic is likely a bit better than the typical manual transmission alternative 'cuz the logic module barely raises engine rpm when letting out the clutch... typically much better than most manual transmission drivers do- or could do. Having said this.... who out there still knows how to drive a manual - and therefore recognizes this and drives accordingly?
Also, left to its own devices (i.e. not typically driven in manual mode) I suspect the synchro's will not wear terribly over time. Downshifted at speed repeatedly: not so much.
I agree: why put 'em in anything but performance cars. Modern "tight" torque converter automatics offer few downsides, probably will last longer, and offer torque multiplication at start-up.... so really, they are well nigh comparably quick.
In a non-performance application I'd try to get a conventional A/T and I'd do frequent pan filter changes / fluid drops.
My understanding is that DCT doesn't wear well in SnG traffic. It's akin to riding the clutch all the time...
...I really can't fathom why these units are in anything other than high performance cars
Driven by a person who knows how to drive a manual trans the clutch wear in city traffic is likely a bit better than the typical manual transmission alternative 'cuz the logic module barely raises engine rpm when letting out the clutch... typically much better than most manual transmission drivers do- or could do. Having said this.... who out there still knows how to drive a manual - and therefore recognizes this and drives accordingly?
Also, left to its own devices (i.e. not typically driven in manual mode) I suspect the synchro's will not wear terribly over time. Downshifted at speed repeatedly: not so much.
I agree: why put 'em in anything but performance cars. Modern "tight" torque converter automatics offer few downsides, probably will last longer, and offer torque multiplication at start-up.... so really, they are well nigh comparably quick.
In a non-performance application I'd try to get a conventional A/T and I'd do frequent pan filter changes / fluid drops.
Does anyone here know what is involved in changing the clutch pads in these dry-clutch DCTs? Maybe they're closer to a wear item like brake pads than they are to a typical clutch.
Hopefully the manufacturers made it easier to replace these than in a regular manual tranny clutch where you typically have to drop motor and trans to get to the clutch. Perhaps the clutch material can be replaced without removing the engine or trans.
Hopefully the manufacturers made it easier to replace these than in a regular manual tranny clutch where you typically have to drop motor and trans to get to the clutch. Perhaps the clutch material can be replaced without removing the engine or trans.
Last edited:
It may have been mentioned, but what toasts a lot of dry clutch DCTs is if the trans develops even the slightest of seal leaks and the gear/trans oil gets onto the friction surface. Same risk applies to a regular MT too I suppose. Seal leaks are what got a lot of the Ford Focus and Fiesta DCTs earlier on.
Given their track record - and I agree with your comments - I'd never consider getting a dry clutch DCT. Seemingly, the same oil seal leak possibility does NOT make regular manual transmission vehicles fraught with issues. Who knows why... Likely 'cuz the human computer - our brains - may compensate to some degree better than a PCM?
Last edited:
Originally Posted by Vaca
Hopefully the manufacturers made it easier to replace these than in a regular manual tranny clutch where you typically have to drop motor and trans to get to the clutch.
Quite the opposite with Hyundai.
The dealers don't attempt to repair. They only replace faulty DCT.
I avoided the DCT when I bought my Tucson last year.
I don't mind taking a second longer to get to 60mph, just so long as it reliably takes off every time I hit the gas.
Hopefully the manufacturers made it easier to replace these than in a regular manual tranny clutch where you typically have to drop motor and trans to get to the clutch.
Quite the opposite with Hyundai.
The dealers don't attempt to repair. They only replace faulty DCT.
I avoided the DCT when I bought my Tucson last year.
I don't mind taking a second longer to get to 60mph, just so long as it reliably takes off every time I hit the gas.
- Status
