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When looking up the correct drive (output shaft) and driven (end of the cable) speedo gears in the 1980/89 truck parts catalog, three things must be known.
Axle ratio, trans type and tire size. How many 1980's F350's (or F250's) came with factory installed 215/85/16, 235/85/16 or any other size of P-Metric radial? NONE!
If I knew what the 235 tires on your truck cross referenced to the original tire size, then I can give you the info.
I know the 235 were not the original.
However I got the original size from the door sticker. This truck I believe was an original chassis cab truck it that makes a difference.
Here is a picture of the door sticker.
Originally Posted by NumberDummy
But even with this, the speedo will not be 100% accurate, because P-Metrics are a different shape than the original bias ply polyester and non P-Metric radials that were factory installed.
100% is not required at all. I'd like to be within 2-3 mph if I can. This way when I loan the truck to a friend he will know if he's speeding.
hadfield, the first part of your VIN, 2FTJW35L is exactly the same as mine, if you look right underneath that it says "truck" your truck was a complete F350 crew cab DRW just like mine except 85 rather than 86 and a 4 speed instead of a C6. Here is the label form mine.
Bill, can you get him in the ballpark using my truck's information but with his transmission? My label and his both show the LT metric tires, or should it be tyres since they are both Canadian built. LT215 is an 8.50-16 as near as I can determine and LT235 would be a 9.25-16. I can pull my old C6 driven gear and get a tooth count if that will help.
Last edited by 85lebaront2; Mar 8, 2012 at 12:24 PM.
Reason: typo
That place (Dennis Carpenter Ford) is right down the road from me. I keep wanting to go by there but haven't yet. That's the extent of my contribution to this discussion!
Good going kedwin, I'l be interested to know what your mpg are once you have the odometer reading right.
That place (Dennis Carpenter Ford) is right down the road from me. I keep wanting to go by there but haven't yet. That's the extent of my contribution to this discussion!
Good going kedwin, I'l be interested to know what your mpg are once you have the odometer reading right.
Kind of hoping that the MPG will be about the same. I figured it on GPS speed and mileage not the speedo because it was so far off.