Date: Sat, 20 May 2006 11:17:11 -0700
Reply-To: mark drillock <drillock@EARTHLINK.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: mark drillock <drillock@EARTHLINK.NET>
Subject: Re: Speedometer Ok -Odometer and trip meter dead!?
In-Reply-To: <008e01c67bfd$5952d1a0$647ba8c0@MAIN>
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On the Vanagon odo I have in front of me, the bridge gear disengages the
1/10 th gear well before the mechanism to reverse all the wheels to zero
engages. If I slightly push and hold the rest button I can freely spin
all the digit positions of the trip meter to whatever numbers I want. I
need to push it in about 3 times as far if I want to reset them all to zero.
As to your theory that something could bind the 10ths gear to it's
neighbor even after the bridge gear has withdrawn, I suppose it could.
Seems unlikely unless someone has sprayed or dripped something in there
that they shouldn't have.
None of the 3 versions of 7 VDO Vanagon speedo instruments I just looked
at have a pot metal gear visible. The failure prone gear is the plastic
one external to and on the input shaft of the main odometer. These tend
to crack and then lose their friction hold on the shaft. I have seen
some that slipped laterally out of position without any apparent crack.
I push my reset buttons while moving any time I feel the need.
Mark
Robert Fisher wrote:
> I have mine out and in front of me (from an '87) and when you push the
> button while rotating the odo by hand in the proper direction, it
> forces the
> trip odo gears in the opposite direction from rotation to reset them-
> but it
> should at the same time disengage the fat black drive gear in the trip
> odo
> from the white 'tenths' gear. However I noticed that when I first
> began to
> fiddle with it that those two gears seemed to have another connection
> that
> worked almost like a ratchet. When I pressed the button while turning the
> main shaft there was a distinct and abrupt 'catching' action. As I
> manipulated them more and attempted to move them independently with the
> button pressed they began to move more freely. At first I thought I had
> broken something but now I think there was just some gunk in there
> that was
> binding them at one spot. They now move quite freely and it still works
> properly and more smoothly than before.
> I can readily picture that these two gears got gunked or gummed up and
> that
> while it didn't require a great amount of force to move them past the
> sticking point it was almost certainly enough to dislodge that crappy pot
> metal gear from its press on the main shaft after repeated applications.
> Pushing the button moves the lever against the cam on the odo gears-
> if the
> tenths gear is stuck in some fashion to the drive gear the force gets
> transferred to the intermediate gear between the two mechanisms and
> then to
> the pot metal gear, which eventually loses its grip on the shaft. No
> mystery, no myth. It's just so poorly designed it can't overcome a little
> grit. ..............
