mgs
[Top] [All Lists]

Jumpy Speedo

To: <mgs@autox.team.net>
Subject: Jumpy Speedo
From: "B. Schiefelbein" <bjschief@acay.com.au>
Date: Thu, 22 Apr 1999 17:29:15 +1000
Hi List,

I am new to this MG (Midget) DIY so I hope the questions aren't too basic.

Firstly my speedo reads approx 9 mph faster than it should.  ie when I am
actually travelling at 37 mph it reads about 46 mph.   I have changed my
tyres from 145 SR 13ZX to 155/70 R13 75T but I didn't think the change
should cause such a drastic speed change.   The original speedo was damaged
and the replacement speedo still reads approx 9 mph fast.

Secondly, the speedo needle jumps (or varies across 4 mph) whilst driving.
I once had this problem on a Datsun 200B and the problem was a filthy speedo
cable and cable housing.

My question is... could the worm gear which drives the speedo cable be worn
(ie the bit where the speedo cable slots into - not the worm itself) alowing
the cable to slip occasionally and therefore cause the speedo needle to jump
?? .... and....

would this be part of my false reading problem or are the tyres the culprit.
(Logically I would assume (<-- yes I know it's dangerous) that if there was
slippage the speedo would read slower but I ain't that technical.

Any assistance would be appreciated.

Bruce S
Sydney Australia
Midget '69  YGN41163


<Prev in Thread] Current Thread [Next in Thread>