Speedo Cable Gear
The speedometer on my 1969 F100 4x4 hasn't worked since I bought the truck and I'm finally getting around to fixing it. I've narrowed the problem to the speedometer cable gear--mine has worn a dip in the middle of the gear, so I don't think it's engaging with the one in the tranny anymore. Does anyone know how many teeth my replacement should have given the following data:
Tire Diameter (rolling): 33"
Tire Circumference (rolling): 103 2/3"
Rear End Gear Ratio: 3.70:1
Transmission: 4 Speed Manual with 1=granny
Thanks in advance for your help!
But, an easy way I think would be to buy the same gear then figure out what % off the speedo is and then buy the correct gear. Another option, if the 3.70 gears are stock, is to determine what the stock tire size was back in 69 and get the % difference in size and buy the correct gear that way. I think the first option is prolly easier. Good luck.







