Speedometer Cable Gear??

6hypo5conv_old · April 10, 2009 at 10:13 AM

What is the correct gear for the Toploader 4 speed with the 3.50.1 rear gear ratio w/stock tires?? I keep seeing the number of teeth listed but have no idea which one I need. Thanks!

BoS_old · April 10, 2009 at 11:12 AM

Hi,

I used the program from Bowling and Grippo to calculate what you need. Added the following parameters: Tire diameter, 24.83",

rear axle ratio, 3.50:1 and number of teeth on drive gear, 6 which gives the driven gear teeth numbers to be 17.

Check the diameter of your tires to be absolutely sure.

Also the HiPo trans (Top Loader)has 6 teeth on the drive gear.

Make sure you use the correct teeth type, left.

Hope this helps,

/Bo

6hypo5conv_old · April 10, 2009 at 8:22 PM

OK, I think I understand.......My resto guy said there was something odd about the gear in the trans.....it IS THE VIN stamped original trans for the car so I need a 17 tooth left-handed gear?? I always have known that Ford color-coded their gears for ease of getting the correct one.....is there a particular color gear that has 17 teeth and is left handed??

CharlesTurner · April 10, 2009 at 9:23 PM

Should be purple colored with 17 teeth, C2DZ-17271-G, LH gears.

May just have purple on the tip, not completely purple.

6hypo5conv_old · April 11, 2009 at 9:54 AM

OK, Thanks again Charles! I'm looking in my parts catalogs now....NPD shows a Purple gear in LEFT HAND rotation with 17 teeth, either in original or repro.....

6hypo5conv_old · April 20, 2009 at 8:52 AM

OK Guys, I have found my ORIGINAL (I think) speedo cable gear from my K: It has 17 teeth, and is the LH rotation-looks like the LH one in the pic in the NPD catalog execpt mine has teeth where the one in the NPD catalog shows smooth.....I am looking at mine now and there seems to be a "17 P" stamped on the top is this for 17 teeth-purple?

Would using an incorrect (possibly a RH rotation) let the speedo still work but erracticly??

C6ZZKGT · April 20, 2009 at 10:09 AM Official Post

Rick, If you use a right hand rotation gear the speedo will work for a while until it grinds the gears down on both the drive and driven gears. I have seen a lot of this over the years. Do not run the incorrect helix gear. The 17P that you see on the gear is actually a 17T meaning the number of teeth to save you the time of counting the teeth. If you need an NOS Ford one, I do have one.

-Fred-

6hypo5conv_old · April 20, 2009 at 11:59 AM

Thanks Fred for the info, I think I'm ok with the one I have, I don't plan on running with the incorrect gear in it for long.

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