A recent
thread on "The MGB Experience" web site made me think about sharing this with every
one of my MGB friends. Instead of buying throttle cables from Moss or VB
and having to deal with the questionable quality of some of the imported
items, I decided one day, to try to make my own cables. This is how I went
about it.
First, a trip to WalMart yielded a pair of bicycle brake
cables to be used as my raw materials. The cables come with one end
already attached and a 3/8" diameter barrel that slipped around this
end to provide a larger end. This end can be used as is, but I cut them
off and start from scratch. I make up some one piece barrels from brass
round stock to replace the supplied ends.
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Notice that
there is a funnel shaped hole in one side of the barrel and a smaller hole
that goes all the way through, just large enough to slip the cable
through. After passing the cable through from the small side, I spread the
wires that the cable is made of so that the cable cannot pull back through
the small hole. I pull the cable back as far as it will go so that the
spread section is inside the cavity, and then fill the cavity with solder.
I have used both acid core and rosin core solder and find that either will
work as long the cable is good and clean. I use a medium sixed Weller
soldering gun or a big soldering iron suitable for sheet metal use. Both
work, but the bigger the better. A small iron or pencil just does not have
the heat needed. I have even used a torch but found that it was overkill
and likely to damage the cable. After the barrel is soldered on one end, I
cut the cable to length. For SU HIF-4 carbs I use 36" inner cable and
a 23" sheath. I then use the soldering iron and solder to tin the
other end of the cable for an area 1 1/2" from the end. To tin the
cable, I simply heat the cable up with the soldering iron, add a bit of
solder so that it penetrates the cable, remove the heat and then before it
cools, I wipe it off with a wet rag. This removes the excess solder and
leaves just the solder that is inside the cable. |
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This helps
keep the grub screw in the cable clamp from distorting the cable and
causing it to fray. If you have ever tried to reinsert a frayed cable
through the tiny holes in the sheath stop and then back through the cable
stop you will remember how hard it is to get the hole cable back through
the tiny hole without having a stray wire or two missing the hole
completely. With the end tinned, it becomes one single wire, and is solid
enough so that you can clamp down on repeatedly without damaging it. |
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The
third thing I do is to drill out the little tower that the cable goes
through that mounts on the firewall to fit the ferrule on the end of the
cable sheath. I sometimes have to turn a new adapter to reduce the size of
the hole so that the sheath will not pass through. If you sheath passes
through the tower, your throttle will not operate. |
BTW, even if you buy new cables for one of the MG parts dealers, I highly recommend
that you tin the end of the new cable to prevent it from fraying. This
works on choke cables, as well. Different car setups require different
cable and sheath lengths so it would be wise to measure your old cable and
sheath before discarding it. Oh, and be sure that you clean up the areas
where you used solder to get rid of all the flux from the solder.
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As
of: 16 April 2006 
