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Classifieds => Wanted => Topic started by: smurfee on 2015-04-29 08:22

Title: spedo gear
Post by: smurfee on 2015-04-29 08:22
   I am getting a new spedo cable from NAPA, I have a 302 - C6 in my 57 custom- how mant teeth do I need on the plastic gear that goes into the trans???? :unitedstates: :icon_bigsmurf: SMURFEE
Title: Re: spedo gear
Post by: lalessi1 on 2015-04-29 21:51
I have been told that 1000 RPM on the speedometer cable should read 60 mph on the speedometer by design. The number of teeth on the speedo drive gear, the number of teeth on the speedo gear inside the transmission, the rear end ratio and the tire size all factor in. The calculation of the constant is a little long but simple.

Number of teeth on speedometer driven gear = 20.168 / tire dia (inches) X rear end ratio X number of teeth on the 
   speedometer drive gear

For example a 27" diameter tire with a 6 tooth internal transmission speedometer drive gear and a 3.89 rear gear would need   
             20.168/27 x 3.89 x 6 = 17.4 teeth... 17 or 18 tooth driven gear. 17 would read a little high, 18 a little low.

   
Title: Re: spedo gear
Post by: Lincoln4002 on 2015-04-30 17:22
If thats a pic of your 57, I have some spare parts you mighyt be interested in.
Title: Re: spedo gear
Post by: smurfee on 2015-04-30 20:05
lincoln 4002 thats my car, what things are you talking about ???
Title: Re: spedo gear
Post by: JPotter57 on 2015-05-01 08:10
Long time no see Don...where ya been hidin'?
Title: Re: spedo gear
Post by: smurfee on 2015-05-01 21:22
HI JAY, been here, just not talking - thanks for caring
Title: Re: spedo gear
Post by: RICH MUISE on 2015-05-02 19:46
Jpotter=James