C 6 Speedo gear replacement
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C 6 Speedo gear replacement
I have an 81 E350 With a dana 61 Trac lok I just replaced the stock 4:10 Gears with 3:54s It has 9.50 16.5 Tires 29In High C6 trans 460 engine It appears to be 4mph faster at 25 And 9-10 mph faster a 60 Any recomendations on what speedo gear to Use
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Joined: May 2003
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Most of the time changing the driven gear by one tooth will change the speedo by 5mph. The drive gear is machined into the output shaft and can be changed only by replacing the output shaft. (2 wheel drive, 4x4 has the drive gear in the transfer case.)
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Joined: Oct 2003
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From: Western Central NV
You can change the plastic gear that runs off the worm gear on the output shaft. Follow your speedo cable to the trans or transfer case. remove the bolt pull the the metal piece out on the end should be a plastic gear, count the number of teeth. If you google speedo gears TCI has a chart. you will increase the teeth. On my wife's Dodge D250 when I changed gears, (the same as you did same ratio) I went from a 30 tooth to a 35 tooth.
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I'm not sure about the 30 tooth count or going to a higher # of teeth I have read 200 of the 500 posts related to speedo gears From what I read sofar The tooth range is 16-21 ? The the drive gear is part of the shaft with a 6 tooth on the shaft ? I need to decrease the # of teeth to Show a higher speed ? Each tooth is worth about 5 mph ? I have a blue gear now that was stock with the 4:10s I have automatic no transfer case My ? would be do I go higher or lower tooth count from my blue gear (sorry I don't have the tooth count of the blue But do know it's blue)
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Thanks for the advise I thought going less teeth was the way to go I ordered a 16 tooth today The on line calculator said it would be a 15 But the dealer said 16 was the lowest So I'll try it I sure like the new 3:54s Better than the 4:10s it had
