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#1 Speedometer drive
Posted: Fri Mar 20, 2026 10:26 am
by 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 ?
#2 Re: Speedometer drive
Posted: Sat Mar 21, 2026 11:45 am
by 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.
#3 Re: Speedometer drive
Posted: Sat Mar 21, 2026 6:52 pm
by Jeremy1954
Many thanks.
#4 Re: Speedometer drive
Posted: Sun Mar 22, 2026 2:00 am
by abowie
If you disassemble it carefully you can probably fix what's wrong with your old one.