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RE: Gearbox update

To: "'Spitfire List'" <Spitfires@autox.team.net>
Subject: RE: Gearbox update
From: Dean Dashwood <DDashwood@softwright.co.uk>
Date: Fri, 11 Jun 1999 08:55:00 +0100
Ok, an update:

First of all, thanks to everyone who replied to this.

As far as the clutch is concerned, a couple of people have had similar
problems - thanks especially to Mark Haynes who suggested somewhere I
could get one that fits!  Mark - I'm not going to follow this up just
yet, because the clutch is fine with the current pressure plate, but
I'll keep the details for future reference.

Onto the overdrive.  Most replies centred around the adjustment of the
"cam thingy" in the gearbox that activates the inhibitor switch.  A
couple of people thought it might be the switch itself, or the way the
switch was fitted.  I started off investigating the switch, simply
because it sounded a lot easier!  Couldn't see anything wrong with the
way it was fitted (couldn't really see how it could be fitted wrong,
except for not being tightened enough!) so I replaced it - and got the
same problem with the new one.

Then, just as I started trying to dismantle the gearbox, I realised that
there was a fairly thick gasket-like-thingy around the base of the
inhibitor switch.  I'm fairly sure this isn't providing any oil-leak
prevention - the oil will have to work its way through the thread on the
bottom of the switch first, and it's not under any pressure at this
point (at least I don't think it is!)  I checked all the catalogues and
manuals I have, and none of them showed this thing.  The only purpose it
seemed to have was as a spacer, keeping the switch apart from the
gearbox slightly.  So I took it out - and everything works!

I think this matter is now closed, unless anyone's going to tell me how
vitally important this gasket is, and that I have to put it back in
unless I want serious gearbox damage.

Once I've done a few thousand miles, I'll send out another e-mail to let
you know how the gearbox is holding up over time.

>----------
>From:  Dean Dashwood
>Sent:  04 June 1999 11:43
>To:    'Spitfire List'
>Subject:       Gearbox update
>
>
>I said I'd update the list re. my gearbox, so here goes:
>
>To recap: when my gearbox blew up last week, I decided to get a
>reconditioned unit from John Kipping, and getting a local (non-LBC)
>garage to fit it.  I also asked them to check the clutch while the
>gearbox is off.
>
>The garage checked the clutch as I asked, it was worn almost right down
>- certainly worth changing.  They ordered a clutch from their local
>supplier, fitted that and the recon gearbox, and road-tested - the
>clutch was not releasing properly.  After a while, they discovered that
>the cover plate on the new clutch was a lot thicker than the one that
>came off the car.  They assumed they'd been supplied the wrong part, so
>they went back to their supplier - no, that's definitely the right one.
>So they tried another supplier - who delivered the same, too-thick
>cover.
>
>Eventually, they decided to use the old cover - it was only the friction
>plate and release bearing that really needed replacing.  So the question
>is - did both of the garages supplier send them the same wrong part
>(unlikely) or does my car have a different cover to standard (why would
>anyone do this)?
>
>Ok, so clutch problems sorted out (albeit with some questions
>unanswered) I got the car back - with the reverse light and overdrive
>not working.  I took the tunnel off and found that all the wiring had
>been connected wrongly.  Took me a minute or two with a multi-meter to
>figure out what goes where, but eventually got it all straightened out.
>
>Now, the reverse light works fine, and overdrive works fine in 3rd gear
>- but doesn't work at all in 4th.  I got out the multi-meter to figure
>out what's going on, and here's what I found.  Gearstick in 3rd gear -
>12v across the overdrive switch.  Gearstick in neutral, but pushed over
>towards 3rd/4th gear - 12v.  Push the gearstick into 4th, and you get
>12v as the syncro-mesh engages, but 0v as it actually goes into gear.
>
>So, is this a problem with the way the gearbox was fitted, a faulty
>gearbox, a faulty inhibitor switch, or something else I haven't thought
>of?
>
>I regret letting the garage do this now - the extra time/cost involved
>negated all the reasons I decided not to do it myself.  Next time, I
>don't think I'll bother!
>
>Anyway, the gearbox itself seems fine - the gearchanges are a tiny bit
>stiff, but not a hint of groaning on any gearchange.  But this is what
>you'd expect immediately after fitting it - it's how it holds up over
>time that counts!  I'll update the list again after I've done a bit of
>mileage.  In the meantime, if anyone has any answers to the questions,
>I'd appreciate it!
>
>Dean Dashwood
>'77 Spit 1500
>
>

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