我不相信這是我獨有的感覺，所以搜尋了國外的文章。
按我的情形，比較像是下面標註的狀況。
http://www.focusfanatics.com/forum/showthread.php?t=306863
PowerShift 6 Speed Operating Characteristics
Background
In 2010, Ford launched an all new transmission, PowerShift, an advanced six-speed automatic transmission based on manual transmission technology with class-leading fuel efficiency. This communication will help explain the technology and common operating characteristics of this new transmission found on the Fiesta and Focus in order to improve customer expectations and
experiences. PowerShift is an advanced automatic transmission technology
The PowerShift is really like two 3-speed manual transmissions put together, with the dual clutch and shifting components controlled electronically. Since most of the components are derived from a manual transmission, the PowerShift transmission will drive, sound, and feel like a manual transmission but without the driver interaction.
Service Personnel Support
Since PowerShift Transmission is a new technology, some customers might not be familiar with the normal driving characteristics of this transmission. Service support personnel should be aware of the normal operating characteristics and be able to differentiate between normal characteristics and abnormal symptoms that require service. The following information will
assist with addressing certain potential customer concerns.
Common Characteristics of the PowerShift Transmission
Common Sounds a driver may notice are:
. Double clicking metal sounds. These noises can likely be heard while driving on very smooth surfaces during a 1-2 upshift or a 3-2-1coast down. The sounds occur with every gear engagement, but generally cannot be heard over the background engine, road and wind noises at higher speeds. Most noticeable if the windows are down and the radio is off, these sounds are of the shift forks moving and the synchronizers engaging a gear (similar to a manual transmission). These shifting sounds are part of normal operation.
. Coast down whine. A slight gear whine while slowing or coasting is normal
. Clicking sounds after the engine is turned off. As the vehicle is powered down, the
transmission will cycle the clutches to the released position so it is ready for a safe restart of the engine. This is part of normal operation. Clicking sounds from the
transmission immediately after the engine is turned off are normal.
. Low speed grinding. A slight grinding noise may be heard at about 2 MPH. This noise
is more evident during “trailer-hitching” events (see below). This noise is caused by a
normal bearing rotation and does not affect the durability of the transmission.
. Reverse gear whine. Some PowerShift transmissions will exhibit gear whine in reverse. The level of whine has been significantly reduced in later build vehicles, but can still be detected to some level. This is characteristic of many manual transmissions, and is not a defect or a situation in which a repair should be attempted
Trailer-hitching feel.
Some customers may experience a trailer-hitching feel (or a slight
bumping feel). The trailer-hitching feel may occur in lower forward gears – particularly if the customer is off and on the throttle quickly. It may be more noticeably in a parking lot or when a customer is doing multiple on/off throttle pedal maneuvers. This trailer-hitching/engagement feel is a normal characteristic of the dry clutch-equipped manual transmission design.
Conversely, conventional automatic transmissions are equipped with a torque converter. The torque converter is a fluid coupling device which dampens these positive engagements feels. Diagnostic tips to be used during service visit When evaluating a customer experience regarding this transmission, first compare to a like vehicle. The like vehicle should be at the same transmission fluid temperature as the customer’s vehicle. Sounds will change as the transmission oil changes temperature and viscosity. If the suspect sound is similar to a like transmission at the same temperature, then it is most likely a normal characteristic and no repair attempt should be made.
If the vehicle loses electrical power due to the removal of a power or ground battery cable, or the battery discharges, the transmission will perform an initial system status check upon power restore to verify shift motor position. This results in a series of mechanical noises for 10-30 seconds. The transmission will not engage and the vehicle will not move while this is
happening. This is normal after an electrical power loss to the transmission.
“Green” clutch break-in period
New, replacement, and reset clutches are “green” and require a break in period before shift event quality is maximized. During the break-in period, green clutches may exhibit:
.
A rattle noise similar to a loose catalytic converter shield. This noise is commonly heard after light throttle 1-2, 2-3 or 3-4 upshifts. This rattle noise will diminish greatly as the clutch completes the break-in.
. A take-off shudder/launch judder (shaky vs. smooth).
. A harsh-shift feel during the first few cold shifts before the transmission reaches operating temperature.
All of the above conditions will diminish and the customer will notice progressively better launch and smoother shifting within the first few hundred miles of mixed driving as clutch break-in occurs. Note: The break-in process may take longer for highway driving, where the clutch is not shifting.
The transmission will automatically learn and make adaptations during shifting events, so it is important to evaluate after allowing sufficient driving time for adaptations to occur.
This green clutch feel may reappear if the clutch touch points are reset and/or the clutch is removed and/or replaced. The condition may last longer for a clutch replacement than a reset. A reset may take up to 100 miles to get the new touch points learned to the point of not making
any of the out-of-adjustment noise. A clutch replacement may take up to 1000 miles to reach break-in dependent on the customer style of driving.
The break-in period can be minimized by performing the adaptive drive cycle exactly as described in the Workshop Manual, Section 307-11 (Fiesta) and 307-01 (Focus)按理來說，3000km的車應該已經學習完畢，不會再有這種現象。但上文的說法是如果去做過Clutch reset，就要再重新學習。也許這台租來的車剛去保養過吧! Who knows!
