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Re: Speedo problem

To: Jim Stuart <jimbb88@erols.com>
Subject: Re: Speedo problem
From: Rene and Marion van Maanen <renevm@support.neth.hp.com>
Date: Tue, 26 May 1998 22:18:59 +0200
Jim Stuart wrote:
> 
> Just for a change, I thought I would share a solution rather than a
> problem with the list.
> 
> At our club's last tech session, one of the guys had a 80 B with a
> speedo that would work for 10-20 miles, then quit. He had taken the car
> to 2 of the local shops, with no results but a new cable.
> 
> We took the cable loose from the speedo, but left it connected to the
> trans. Jacked the rear up, put the car on jack stands, started it up,
> put it in third, watched the end of the cable turn. First thought was a
> bad speedo. As I picked up the end of the cable to look at the condition
> of the square drive end, it stopped turning. releasing it, with a little
> encouragement, it started to spin again. Since this was a new cable, it
> seemed unlikely that it had a break. Now we new the problem was in the
> angle drive or the speedo gear. Both had been previously inspected at
> the 2 shops, but somehow they had to be the problem.
> 
> Removed the angle drive & speedo gear. One of the other guys looked at
> the angle drive & pronounced it fit for service. He said the gear looked
> OK too. I looked at the gear, the square socket end looked fine, not
> rounded out at all. Teeth looked good, all in all, looked like a new
> gear. While fussing with it, looking for some symptom of demonic
> possession, I realized that I was turning the plastic gear while holding
> the steel shaft stationary.
> 
> Apparently, the plastic gear is an interference fit on the shaft, with
> no key or other positive stop. When cold, everything worked fine. As
> soon as things warmed up, the shaft became stationary, while the gear
> turned.  Solution is a new gear if one can be found. Home-brew fix that
> may work is green Locktite, the version that is for assembled parts, as
> it will weep into the gap. Don't know if it will work on plastic. Next
> try will be to try to drill the gear & shaft & insert a pin. Not very
> confident that this can be done without going to a machine shop. Long
> way to frill a very small hole.

Well, Jim

Checked it this evening. Unfortunately, not the solution for MY car.

Rene
-- 
Rene and Marion van Maanen
Netherlands Europe
SOHC #252 sohc4@dorje.com     Honda CB360T ['76]
                              Honda CB350F ['74]
                              Honda CB750K2 ['75]
MG list mgs@autox.team.net    MGB GT ['68]

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