>I posted this on the Triumph list, but no answer. My speedo is reading
>too high. I have an overdrive tranny which I assume is original. I
>haven't been into the differential to count the teeth on the ring gear
>yet, so I don't know which it is. But my speedo has these numbers on it:
>SN6203/20 and further to the right: 980.
>****************************************
Jim,
Mine, is exactly what you have. The 980 number refers to the number of
revs of the speedometer cable per mile. All speedometers have this number
somewhere on them. Mine is from, a 1970 GT6 WITHOUT overdrive, and a 3:27
rear end ratio. Your commission number indicates an overdrive was fitted
to your car, and there is a different p/n for overdrive car speedometers,
so I assume there is a difference?? I installed/fitted an overdrive on
mine and replaced the rear end with the correct 3.89 ratio (for overdrive
equipped cars) and had the speedo re-calibrated to my car for correctness -
sounds' like you have either the rear end for the non overdrive car (3.27
:1 ratio) or the speedo from an non overdrive car - or both. Either way it
would be cheaper to have it cleaned and re calibrated for your car than to
replace it with a new one-
Barry Schwartz (San Diego) bschwart@pacbell.net
72 V6 Spitfire (daily driver)
70 GT6+ (when I don't drive the Spit)
70 Spitfire (project)
73 Ford Courier (parts hauler, rain vehicle, getting a V6 soon!)
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