Rob, based on your commission number, your car should have an OD from the
factory. Whether or not the OD unit in your car is the original one is
another issue. In any event, the OD will not affect the speedo reading.
Having said that, I think in 76 the OD units had a different speedo drive
gear fitted (look in the TRF catalog for specifics). That year also had a
different speedo. I don't know what the specifics are, but I believe they
are different. On my 76, the speedo is original and reads correctly. My
numbers at the bottom of the speedo face are SN 6411/10 1000. A lot of TR6s
I have seen (pre-76) with the same style speedo (ie. the later style with
half chrome bezels) have 1184 in place of the 1000 on the face. I think this
number represents the number of revolutions of the speedo cable per mile of
distance traveled. You might check what your speedo says and if it appears
original.
Another thing which might be relevant is the diff ratio. Stock north
american TR6s had 3.7:1. Other diff ratios are available so perhaps your
diff ratio was changed?
Finally, you don't state what tires you have but that could also affect the
readings. Although to be out by +20% would require a pretty large decrease
in tire diameter!
HTH.
Peter Zaborski -- CF58310 UO
> -----Original Message-----
> From: Robert Reynolds [mailto:robreyn@home.com]
> Sent: June 1, 2000 7:48 PM
> To: 6pack@autox.team.net
> Subject: Optimistic Speedometer and Odometer
>
>
> My 76 TR6's Odo- and Speedo both register 21% fast and I have
> never gotten a good explanation for why this is. Can anyone help?
> The car came from the factory with overdrive, but I don't know if
> it's the original.
>
> TIA
>
> Rob Reynolds
> Reston, VA
> 76 TR6 CF58073UO
>
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