I think I have it figured out. My original speedo is a factory OD calibrated one
for a 3.89 gearing. When I installed the 4.22 rear it will be off and has
nothing to do with the cable. So the choices are to either swap the speedo head
for a 4.22 or find an original 3.89 rear for a S2. Sound correct? Brent
Victor Hughes wrote:
> Brent
>
> I wouldn't have thought a cable would make any difference, because all it
> does is transfer revolutions from the OD speedo offtake to the back of the
> speedo - there is no gearing up or down effect. The problem could either be
> the OD pinion or the speedo. What was the donor car for the OD unit? The
> reason I ask is because ODs from Series 3s have a different number of teeth
> on the speedo drive pinion to all other series - because S3s have 3.89 rear
> ends. If you have an S3 OD your S2 speedo would read wrong. I'm fairly
> sure it would read fast (as you have described). However even that would
> not account for all the discrepancy and I suspect you speedo and possibly
> your tach is also out.
>
> Hope this helps
>
> Vic Hughes
>
> Brent Kasl wrote:
>
> > I need help from the list. My S2 has a S5 rear axle of 4.22. I installed
> > an OD unit earlier this year which is electrically disconnected due to a
> > malfunction. My speedometer is an OD rated speedo. It has always
> > fluttered when registering so I replaced my original with an OD cable.
> > Now the fluttering is gone, but the reading is way off, much like it was
> > after the OD install. I mean 65-70 mph at 3000 rpm! Is it the
> > combination of the OD unit and the axle causing the problem, or should I
> > install a non-od cable in it? It was off before the cable was renewed
> > but I thought this would help both problems. Thanks Brent
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