Speedometer drive

[Jeremy1954]

I have an American imported series 3. I recently replaced the speedometer drive in the automatic transmission. The speedo now runs about 30% slow. I know the exported cars had a different axel ratio. Is there a correct speedometer drive still available ?

[lowact]

If all you have changed is the "speedometer drive" then this must be the culprit?
What do you mean by "speedometer drive", this thing?


There are two types of these right-angle drives. The one that all e-types are supposed to have has a gear ratio of 14/11 = 1.267. The other type, belongs on some other Jaguars, has a gear ratio of 1.

If you have replaced a 1.267 drive with a 1.0 drive the same speedo would indicate ~27% slower.
To figure out what you have, put a bit of paper in the output end to act as a flag and give the input a twirl.

[Jeremy1954]

Many thanks.

[abowie]

If you disassemble it carefully you can probably fix what's wrong with your old one.