17.2 - Clock Removal from Tach ( 3.8S,
February 5, 2005
Get a small ratchet with a 3'' extension and a 1/4'' socket.
The 3'' extension is needed because the head of the ratchet
will not allow you to get the socket in place.
Set the ratchet in the ''remove'' position. There are two 1/4'' nuts
and washers at the bottom of the tachometer, one on each side of
the clock. A small mirror and a flashlight will help you see them.
You must remove the two nuts. You need to remove the knurled
brass ''nut'' of the setting cable from the back of the clock, and
disconnect the one wire from its connector. Then carefully pull the
clock until it dislodges from inside the tach. It will come out but
gently, no force is needed. When it finally comes out, there is
also a rubber gasket which might fall out.
To reinstall it, get a Glue Stick at any school supply, and glue the
gasket to the clock assembly so it remains in place while re-mounting
the clock. This glue is inoffensive and will keep the gasket in place
just enough so that it will not move while re-mounting.
17.2.1 - Eck Clock Conversion ( Mike Eck,
February 26, 2005
I do NOT remove any parts from the clocks. I use all of the original
mechanism that is in the clock. I ultrasonically clean the clock, then
lubricate the bearing points with clock oil. I carefully clean and adjust
the contacts, and coat them with a thin film of Deoxit D100L contact
cleaner and rejuvenator. Then I install a circuit board which works
with the original mechanism to reduce the contact current and provide
a consistent power pulse to the coil. It still ticks and the time set stem
works as it should. None of the original clock parts are removed, so
the installation is totally reversible, in case you ever want a non-functional
The Smiths clocks are actually very well made, with jeweled bearings and
brass gears. There are no metal tabs. The clocks are assembled entirely
with screws, so individual parts such as the balance wheel, electrical
contacts and gears are replaceable. Since the weak point in these clocks is
the electrical contact, the clocks never seem to run long enough for
anything else to wear out. I have upgraded about 150 of these clocks, and I
have never yet seen one that I couldn't fix.
Thanks for the opportunity to clarify this point. If you need any more
information please see my website, www.jaguarclock.com, or contact me off list.
New Jersey, USA
17.2.2 - 420G Clock Battery ( Larry Martz,
August 14, 2002
Nigel Thorley's JAGUAR MARK VII TO 420G - THE COMPLETE COMPANION discusses
the 420G battery clock on p/134: "In October (1969), the mercury-cell-powered
electric dashboard clock was replaced by one powered by the electrical
system of the car itself. The new clock was part no. C.32437 (old
mercury-cell-powered, C.26989) and this became effective at chassis nos.
GID.57384 RHD and GID.77983 LHD. Due to lack of availibility of the
earlier battery-powered clocks, dealers were requested to amend the wiring
of existing cars to suit the new clock."
NOW, I amplify this somewhat -- Nigel Thorley made NO mention of the
electric clocks in the Mark X, because these were NOT battery-powered, eh!
In fact, for 420G owners, check your chassis #s to determine if your 420G
was built before GID.57384 RHD and GID.77983 LHD -- after October 1969 at
these chassis #s, the 420G reverted to the standard clock, powered by the
Cat's electrical system, with NO battery. I hope this helps