[A4] A4 clutchless shifting

Robert King gt40mkii at gmail.com
Fri Apr 20 11:46:16 EDT 2007

On 4/20/07, Tyson Varosyan <tyson at up-times.com> wrote:
> By sitting at a light with your foot holding the clutch pedal you are
> doing
> serious damage to the clutch system.

Sorry, but I've GOT to disagree with pretty much everything you posted.  If
you like, I can get an authoritative quote from a good friend of mine who
designed drivetrains for Ford, but for now I'll just say:

1. The throwout bearing, while being permanently lubricated, is more than up
to the task of being engaged for extended periods.  Because it doesn't have
a pressurized oil system does NOT imply that it isn't intended for extended
operation.  You do realise that CV joints and wheel bearings are permanently
lubricated, right?  I guess we shouldn't drive our cars for extended periods
for fear of wearing out the wheel bearings, either.

2. Unless its malfunctioning, there is almost ZERO friction between the
pressure plate and the clutch disk.  While its true that the pressure plate
doesn't move much (about 0.125" to 0.25" for a diaphragm clutch -- a little
more for a Borg & Beck-style clutched used in older cars,) there doesn't
need to be much to fully disengage the clutch.  If there were significant
friction between the clutch plate and the pressure plate and/or the
flywheel, you'd experience creep as you sat with the clutch in in 1st gear
on a flat, smooth surface.  This simply does not happen.

While in THEORY, the drivetrain is under less wear when idling in neutral
with the clutch engaged  (the clutch assembly is locked up and the throwout
bearing is not spinning, but the internals in the transmission are.)
Practically speaking, however, it's a non-issue.

-- RK

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