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Re: [T3] who's doing Type 3 work this weekend? (long)


Well I'm feeling dead chuffed with what I did today. I finally bit the
bullet and decided to sort out my carb linkage (previous posts)
I removed the central bell-crank assembly with the intention of getting rid
of its considerable play.
On closer examination I was a bit stumped as to what to do. I had thought
that it had bushes that could be replaced, but it didn't. It is actually a
steel tube attached to a bracket. The ID of the tube is 10mm and its ends
have been swaged down to 8mm. The shaft that the bell crank pivots on is
8mm. Unfortunately the narrowed ends of the tube are only a few mm long so
they don't provide much bearing surface, and on mine the bore was worn and
the shaft had deep grooves worn into it- the spring pressure on the carb
linkage is quite considerable. This allowed 2mm or so play in the assembly-
not good for carb balance.

I thought about making up a new shaft, but there would still be play because
of the worn bores. I contemplated detaching the tube from the bracket and
making a replacement, but that would have been a lot of work. I had some
really nice teflon/bronze lined bushes left over from when I re-bushed my
carb throttle plates, and by chance they were also 8mm bore. They are 8mm
long so they would act on areas of the shaft that weren't worn and they are
low friction and "maintenance free". The problem is they are 10mm OD, so how
could I fit them in the tube that was 8mm bore?

Well I was mulling over several of these ideas when I bumped into a friend
who's pretty nifty in engineering matters. I asked him what he thought I
should do, and particularly what he thought my chances were of opening up
the ends of the tube enough to fit my fancy bushes. Together we formulated a
plan. It was a bit risky as I had no spare, so to get home I had to make it
work! or walk :-( 5miles)-:
What I did was take a length of 10mm silver steel rod and grind a slow taper
on one end - down to <8mm. I heated the ends of the tube to anneal the
steel, and then knocked the "podger" into the tube end, spreading it to 10mm
ID. I did it in a few stages, annealing in between, and it worked- without
splitting the tube! I was then able to press the bushes in and now I have a
completely play free central pivot! This sounds like a lot of work, but
actually it only took a few hours and I can say that I can already feel the
benefits. Its subjective but I feel that the throttle response is more
uniform and precise. Now I just need to replace the short linkages on the
carbs- these are also very important to be play free as they are not under
spring tension like the long ones- the throttle disk can still flap around
uncontrollably. Mine have a lot of play- but they're better than when I
first bought the car- one of them was originally a piece of gardening wire!
Thanks to a very generous fellow listee I hope to sort these out soon and
then my carb linkage will be as good as new, and I might get more than 20mpg
(UK).

Mark Seaton
'73 Thirsty Fasty, London

PS I got one of those purple matchbox fastys at my local junk market this
morning for 25p. Last week I got a red one with the pin wheels for 50p. I'm
wondering how difficult it would be to force the base off each and swap them
over, re-rivet then sell the purple one with pin wheels and buy a real one
with the proceeds- that could be fraud I suppose, but I guess it depends how
you word it in the add ;-)

----- Original Message -----
From: "Greg Merritt" <gregm@vwtype3.org>
> I have to do some B*g work myself... but is anybody but Brian
> doing work on their Type III this weekend?  What are folks up to?
>
> (I also need folks to post to make sure that the list is
> working well...)
>
> -Greg



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