Speedo issues

[grovesa]

Hi,

I have a 1955 803cc minor. I think i have an issue with my speedo.

When driving along the speedo needle wobbles a huge amount, it tends to slow down on the return at roughly the speed im doing and then flicks upwards again.

When travelling at 40mph (according to my satnav) my speedo reads anywhere between 20 and about 70. I would like to stop this if i can, if not being able to stop the excessive swing, then at lest lessening it!

My car is still dynamo run, and on another site there were some threads stating this could be the issue.

Any help is much appreciated

[mike.perry]

The dynamo has nothing to do with the speedo, on sports cars of that period the rev counter was normally cable driven off the back of the dynamo.
The problem is more than likely a damaged speedo cable but before changing it check that it is screwed into the back of the speedo correctly and the gearbox end is tight.

[grovesa]

Few! thats a relief thanks!!

Righto ill check that out first!

[bmcecosse]

Do please tell where you read that nonsense about the dynamo! It is a dry/twisted speedo cable. New cable and it will be fine.

[C6Dave]

It could also be oil contamination in the speedo head. There is another thread about it on site.

I also had a fluctuating speedo which also required re calibrating so got it overhauled and there is no flicker now still using the original cable

How anyone could think that having a dynamo rather than an alternator on a Morris Minor would affect it beggars belief.