The
‘Why’ of it
Most of us take a lot for granted and knowingly or un - abuse our Cars'
Clutches. The present generation 'Diaphragm' type Clutch 'Assemblies are
pretty sophisticated Precision-Metallurgical Devices and any of its basic
design parameters going out of synch can push it into mal-function.
The best bet while overhauling a Clutch which has done ~ 80 kkm in our
traffic conditions is to replace its all the four constituent parts with
‘OE’ Genuine Parts at one go. It’s worth it for an average
motorist since the labour costs and down time are the same to replace
even ¼ out of them.
Some Garages
in the cost saving interests of their Clients try to salvage atleast the
Flywheel part of it by getting it ‘suitably’ turned at the
corner Lathe Shop.
For example,
if I remember it right, the Clutch-Cover Assy Mounting Face on the M800
Fly Wheel and the 'Step' below where the Clutch Plate sits with the Pressure
Plate behind it - is designed to have a 'step-height' of '18.1 mm' with
a
'run-out' tolerance of '0.1 mm'. Given these figs, it's easy to imagine
whether the 'Corner Lathe Shop' is equipped to handle this sort of precision
work.
So as can be visualised,
this hardly ever works out satisfactory and at the end of the day –
the most common fall-out is a ‘Judder’ of various sorts.
Unfortunately, it doesn't end here. I am convinced - out of whatever 'MASS/Shop-Floor'
experience I have - that the so-called 'MGPs', even if lifted direct from
Gurgaon - are OE Rejects ! MUL is not alone in this - unlike in the West.
To over-simplify, a Clutch can 'judder' if :
1) Any one of it's 4-principal Constituents viz - i) The Flywheel face,
ii) The Clutch Plate-Assy, iii) The Clutch-Cover/Pressure Plate Assy and
iv) It's 'Release Mechanism are 'faulty'.
2) It can also Judder inspite of the above 'set-up' being in order, if
the Engine itself is out of tune by way of - i) Ignition Timing and more
importantly - ii) If there are 'flat-spots' in the Carb; either due to
too lean an idle mixture setting or 'otherwise'.
3) In the 'otherwise' Category come - i) Worn-out Butterfly Spindles and
ii) Lack of 'perfect' seal between the Carb mtg Flange/prescribed Gaskets
and the Inlet Manifold.
4) If the Flywheel Face is ‘True', the Clutch ‘Disc/Cover'
Assy is to OE Specs and the Release Bearing Holder Shaft isn't 'dry' in
its top and bottom bushes - assuming the operating Cable is OK - there's
no reason for the Pedal to feel hard or the Clutch to ‘Judder’.
5) It can also judder
due to excessive Slack in the 'Drive-Train' - notably in the 'Final Drive'.
A damaged ‘Spider’ of the Clutch Disc including loss of tension
in its springs can also make a Clutch Judder.
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