speedometer cable
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From: Montpelier, VA
speedometer cable
I did the C6 swap on my '66 about a year ago and all went well. At the time, I used a '68 Mustang speedometer cable to hook up the speedo. While it works ok, the cable is a little on the short side. I'd like to get the proper length cable. If I order one for a '68 F100 with a C6, will that work ok?
Thanks,
Mark
Thanks,
Mark
Ford Parts Specialist
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From: Simi Valley, CA
I did the C6 swap on my '66 about a year ago and all went well. At the time, I used a '68 Mustang speedometer cable to hook up the speedo. While it works ok, the cable is a little on the short side. I'd like to get the proper length cable. If I order one for a '68 F100 with a C6, will that work ok?
What is the length of the Mustang cable you used?
There were two different speedo cables used on 1967/68 Mustangs: 66 9/16" long (A/T) & 77 1/8" long (M/T).
1965/66 F100/250 w/MX C-O-M: C5TZ17260BS = 93.80" long.
1967 F100/250 w/MX C-O-M & 1968/70 F100/250 w/a C6: C7TZ17260AB = 75.42" long.
1971/72 F100/250 w/a C6: C5TZ17260Y = 70.80" long.
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From: Montpelier, VA
Thanks,
Mark
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No one replied about which application would be better for my setup but in the end it didn't matter because NPD listed the same speedometer cable for both applications. Haven't received it yet, but will comment on the fit when I do.
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Got the speedometer cable from NPD(C5TZ17260Y = 70.80" long), got it installed. Works ok, but would have been better if it was a little longer. In any event, on to the next problem.......my speedometer is off by 5 mph according to my GPS. Should I get a speedometer gear (driven gear) with one less tooth on it to correct the error?
Ford Parts Specialist
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From: Simi Valley, CA
Got the speedometer cable from NPD(C5TZ17260Y = 70.80" long), got it installed. Works ok, but would have been better if it was a little longer. In any event, on to the next problem.......my speedometer is off by 5 mph according to my GPS. Should I get a speedometer gear (driven gear) with one less tooth on it to correct the error?
One tooth of the speedometer's DRIVEN gear (end of the cable) is equal to roughly a 7-10 mph difference.
So...if you have say...a 19 tooth DRIVEN gear, and you want the speedo to read faster, deduct one tooth (18T).
If the speedometer is reading slow, add a tooth (20T).
What is the tooth count of your truck's DRIVEN speedo gear?
IMO, you will not be able to get the speedometer to read exactly correct.
This has to do with the type of tires your truck prolly has on it...now, and the variations in the speedo DRIVEN gears.
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I should have been more specific in my previous post. My speedometer reads 50 mph when I am actually doing 55 mph. So I should go to a driven gear with 1 less tooth than what is on there now, correct?
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Each speedo DRIVEN gear is calibrated to between 7-10 MPH, so if you deduct a tooth, the speedo will read a coupla MPH fast.
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From: Montpelier, VA
I used my gps to verify the speed, at 50 on the speedo the gps says 55 mph. I'll try using a driven gear with one less tooth and see what happens. I'm running 235/75/15 tires on the truck, anyone know how that size compares to the stock tire?
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This is why I said getting the speedo to read exact will be impossible.
The original tires/sizes used on 1961/66 F100's: 6.70 x 15, 7.00 x 15, 7.10 x 15, or 7.75 x 15 bias ply.
Ford didn't offer radial tires until the mid 1970's, and then only as an option.
The first US vehicle to have radial tires as standard equipment was the 1966 Oldsmobile Toronado which had FWD.
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I know they didn't come with radials when they were new. What I was referring to was how do they compare in height. I think the 235/75/15 tire is about 28.9 inches in diameter.
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