being careful not to accidently insert dirt or sand while you’re doing
this. It’s best to only lightly grease the upper 6 inches of cable, because
too much grease here can work its way into the speedometer head and
jam it up. If the head itself was in good shape (as determined by the first
test), apply a drop of engine oil to its drive shaft and rotate the shaft
with your fingers a few times. Then attach the drive cable; finger tight is
usually sufficient.
You should now have a fully operational speedometer.
However, let’s say that your speedometer was working, but its needle
flicked all over the dial at slow speeds, and/or fluctuated a lot when
cruising. If the needle seemed to move freely in the spin test — not
actually sticking anywhere, but just sort of bouncing around — your
problem (again) is most likely in the drive cable, where lack of
lubrication and/or too sharp of a bend is causing the inner core to wind
up like a spring and then snap free, making the speedometer needle
jump and bounce.
Pull the drive cable’s inner core and examine it for lack of lubrication
and/or frayed or rough spots. If you find the latter, your best bet is to
get a completely new assembly. If the cable just needs to be lubricated,
remove and clean the whole assembly, then reinstall it using the
methods already described, trying to smooth out any sharp bends.
Chances are this will solve your speedometer problems.
A howl or whine from the “speedometer” is in many cases actually a
dry drive cable that needs to be lubricated. In fact, it would be safe to
say that most speedometer problems are actually caused by a dry or
binding drive cable.
Let’s go back to the beginning, where you first reached under the dash
and turned the speedometer with your fingers. Suppose, instead of
bouncing freely, the needle seemed sluggish and stiff, and/or its drive
shaft was hard to turn and seemed to bind. You could first try a few
drops of oil on the shaft and that might solve the problem, along with
cleaning and lubricating the drive cable. Otherwise, it may be that the
speedometer’s little interior machinery is rusty or dirty. Or it could be
jammed with grease from over-lubricating the drive cable. It’s also
possible that the speedometer is simply worn out, but this is actually
pretty rare because, if properly maintained, a speedometer can go for at
least one million miles.
singke
(singke)
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