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Old Apr 12, 2018 | 09:39 PM
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Speedometer question

Ok,Fellow FTE'rs
A couple of years ago I pulled and rebuilt my motor ( had the connecting cap bearing on #2 walking up under the bearing on the connecting rod ) made an unbearable noise, Hence the rebuild...
When I went to reinstall the motor, I went ahead and pulled the 3.03 transmission (and replaced the clutch at the same time,) connected motor and transmission together on the floor, put both in as 1 unit and finished by hooking everything up and didn't realize that some how when I connected the speedometer cable to the transmission incorrectly that it has been reading 3 - 4 miles under what I am actually doing. [ if it reads 65 mph, I am really traveling at 68 mph ]
I have tried a couple of times by pulling cable out (after making a set of alignment marks on the transmission and cable ) and turning the teeth counter clockwise and still no luck in getting it to read what I am Actually doing
Any suggestions can and will be highly appreciated.
 
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Old Apr 12, 2018 | 09:57 PM
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If it's still stock, it would be a wine colored driven gear....16 teeth if memory serves....

Don't know if you'll find one that'll change your reading as it's only 3 MPH off.

But, there are other driven gears available, different colors for different teeth - at your local Ford dealer. Not sure if the parts stores would carry 'em..
 
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Old Apr 12, 2018 | 10:10 PM
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Originally Posted by Filthy Beast
If it's still stock, it would be a wine colored driven gear....16 teeth if memory serves....

Don't know if you'll find one that'll change your reading as it's only 3 MPH off.

But, there are other driven gears available, different colors for different teeth - at your local Ford dealer. Not sure if the parts stores would carry 'em..

I know that my dad had the clutch replaced back in 1986 but didn't have this problem to "my memory "
And the color is more of the "key lime pie" and it is original to the truck.
 
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Old Apr 12, 2018 | 10:16 PM
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Well, you could pull it, count the teeth..also look for wear on the gear's teeth, mosey down to the dealer and chew da fat with the service dude about the gear(s).

That's about all I have for now.........can't recall if more teeth on the gear will read faster MPH or if less teeth will do it. Too many moving parts this time of day for a grumpy old fart...

Good luck........
 
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Old Apr 12, 2018 | 10:30 PM
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[QUOTE=Filthy Beast";for a grumpy old fart..."

Good luck........[/QUOTE]
Thank you for your input sir, ( I'll leave that up for you to interpret )
I'm just like you just another grumpy ol' fart up past his bedtime...
 
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Old Apr 13, 2018 | 12:44 AM
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3MPH off? How are you judging how fast you are "actually" going? In my mind, the only thing that's going to make that small of a difference is a tire size change.
 
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Old Apr 13, 2018 | 01:17 AM
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Originally Posted by Filthy Beast
Well, you could pull it, count the teeth..
Or double up on the reading glasses and see if you can make out the engineering ID number. They also tend to be marked with the tooth count as well.

Also beware that the tooth pitch has to be correct. Driven gears designed to go into the right/passenger side of the transmission have their teeth pitched 'backwards,' if you're used to transmissions with the speedometer cable hole on the left/driver side.
 
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Old Apr 13, 2018 | 02:05 AM
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Nylon speedometer DRIVEN gears for F100/350's could be TYPE: 2 or 2A / Notice the teeth run this-away: ////

16 thru 21 teeth are available from Ford & auto parts stores.

DRIVEN gears are determined by trans type, rear axle ratio and the original bias ply tire sizes.

If you have P-Metric radials, the speedometer will be off by at least 2-4 MPH



 
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Old Apr 13, 2018 | 09:04 AM
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[QUOTE=burnthelight88;17923266]3MPH off? How are you judging how fast you are "actually" going? In my mind, the only thing that's going to make that small of a difference is a tire size change.[/QUOTE
This little ( tijuana ) burg in commiefornia has a @^$*load of them fandangled digital speed readers throughout the town,
that's how I am judginging my mph and here in commifornia we don't have those yard stickers (mile markers ) on the highway like the rest of All Ya'all in the U.S. of A
 
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Old Apr 13, 2018 | 09:45 AM
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Originally Posted by dads1977
here in commifornia we don't have those yard stickers (mile markers ) on the highway like the rest of All Ya'all in the U.S. of A
Oh. They must be in kilometers...
 
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Old Apr 13, 2018 | 12:02 PM
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Originally Posted by dads1977
This little ( tijuana ) burg in commiefornia has a @^$*load of them fandangled digital speed readers throughout the town,
that's how I am judginging my mph and here in commifornia we don't have those yard stickers (mile markers ) on the highway like the rest of All Ya'all in the U.S. of A
Yeah, I had a feeling you would say that. Police radar and other speed devices used to clock and write tickets get calibrated. Those side of the road speed readers don't. They are wildly inaccurate which is why you can't get pulled over based on the readout alone. Unless cali does things differently, they are essentially a novelty. If it says 3-4 MPH off, I wouldn't believe it.
 
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Old Apr 13, 2018 | 12:30 PM
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I'd trust a gps phone app before those road side speed traps.

If you're truly wondering your speed grab a friend with a stock vehicle and have them drive at different speeds next to you and radio to you their speed and check what your Speedo reads
 
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Old Apr 13, 2018 | 11:37 PM
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Originally Posted by Filthy Beast
Well, you could pull it, count the teeth..also look for wear on the gear's teeth, mosey down to the dealer and chew da fat with the service dude about the gear(s).

That's about all I have for now.........can't recall if more teeth on the gear will read faster MPH or if less teeth will do it. Too many moving parts this time of day for a grumpy old fart...

Good luck........
If I recall... Less teeth would cause speedo to read faster. Just had to swap the speedo gear in my CJ7 due to over-sized tires, and lower gearing. Not aware of any charts for our trucks like we have in the Jeep world, since Jeeps are frequently regeared and/or larger tires installed, the are a few reputable places that lists gear charts to match Speedo gears to the Tire Size and Gear Ratio.

I could be wrong, it's late, and been a long day hah

- J.T.
 
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Old Apr 13, 2018 | 11:52 PM
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check with a handheld gps, It couldbe off. Lube the cable. checkwear on the gear inside. A worn gear leaves inconsistent readings. You can pop the front window from the cluster, and by hand move the stop of the gear slightly to fine tune, just gently push and you feel the needle move, slightly, monitor speed at 30, 50, 65-70, and if off progressively, change components, if off similarly, move speedo neddle stop.
 
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