Paul,
About six months ago, I disconnected my speedo cable from the gauge in
order
to address the bouncing needle problem. In my case the bouncing needle was
caused by old caked up grease in the cable housing. Just greasing the cable
fixed about 90 percent of the bouncing.
From what you say below, it sounds like my cable is not routed
correctly. I
do not have the right angle drive at the top, but there is no sharp bend in
the cable. Here's my question - where should the speedo cable pass through
the engine compartment bulkhead ?? Or is this cable even supposed to pass
through the engine compartment ?? I can't imagine where it would go with a
right angle drive attached.... right, left, down ?
Thanks, Skip '74 B
------------------------------
Date: Sat, 8 Jan 2005 10:02:16 -0000
From: "Paul Hunt" <paul.hunt1@blueyonder.co.uk>
Subject: Re: Bouncing Speedometer Needle
The most common cause, where the needle flicks a few of times per second at,
say, 30mph is a sticky cable or broken strands in the cable. Pulling the
inner and examining it, and cleaning off old grease and lubricating with
thinner oil may help.If not maybe the outer has been damaged, which may not
be visible externally. Also check the routing and make sure any bends are
as large a radius as possible. All MGBs were issued with a right-angle
drive between the cable and the gearbox, and LHD cars had another between
the speedo and the cable. They break and are expensive to replace, and
whilst you can get away without the bottom one, often with a slightly longer
cable, the top one is more necessary.
If the pulsing is much less than that and in time with the odometer movement
it was a dry input shaft on the speedo head in my case. A drop of light oil
solved that, despite frequent recommendations that you should not get any
oil or grease near the speedo.
PaulH.
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