Gary Lewis Posted December 1, 2018 Share Posted December 1, 2018 Recently someone asked what speedo driven gear he needed in order to correct his speedo's readout. I checked my page on speedometer gears (Driveline/Speedometer Gears) and realized I didn't have anything to easily answer that question. But, I also realized that I had three pages - Speedometer Gears, Driven Gears, and Drive Gears. And it wasn't easy to get from one to the other. Given that, I've revised things significantly. Everything is on one page, just in tabs so it is easy to go from one to the other. And, there are now three calculators using embedded spreadsheets. But I need your input as to how and whether the spreadsheets work for you. PLEASE! If they don't make sense, if the directions aren't helpful enough, if there's a mistake, etc then I need to know. Link to comment Share on other sites More sharing options...
85lebaront2 Posted December 1, 2018 Share Posted December 1, 2018 Very good, if I still had a gear driven speedometer. You might want to clarify one item, the $ in the charts, which I believe means the gear is integral with the shaft. Nice calculator program! Link to comment Share on other sites More sharing options...
Gary Lewis Posted December 2, 2018 Author Share Posted December 2, 2018 Very good, if I still had a gear driven speedometer. You might want to clarify one item, the $ in the charts, which I believe means the gear is integral with the shaft. Nice calculator program! Thanks, Bill. I did add: Also, see the note below that says that a "$" in the Drive Gear column means that the gear is actually part of the transmission's output shaft and is, therefore, not replaceable. That was standard on the automatic transmissions. Anyone else? Are the calculators understandable? Link to comment Share on other sites More sharing options...
85lebaront2 Posted December 2, 2018 Share Posted December 2, 2018 Thanks, Bill. I did add: Also, see the note below that says that a "$" in the Drive Gear column means that the gear is actually part of the transmission's output shaft and is, therefore, not replaceable. That was standard on the automatic transmissions. Anyone else? Are the calculators understandable? Didn't try them, mine is electronic so adjustments are done by changing the count multiplier. Link to comment Share on other sites More sharing options...
grumpin Posted December 2, 2018 Share Posted December 2, 2018 Didn't try them, mine is electronic so adjustments are done by changing the count multiplier. Everything seems understandable to me. My rear axle code is 39, which is listed as 3.55. Would I use 3.54 in the rear axle ratio? I've seen this elsewhere if I remember correctly, meaning 3.54 instead of 3.55. Link to comment Share on other sites More sharing options...
Gary Lewis Posted December 2, 2018 Author Share Posted December 2, 2018 Everything seems understandable to me. My rear axle code is 39, which is listed as 3.55. Would I use 3.54 in the rear axle ratio? I've seen this elsewhere if I remember correctly, meaning 3.54 instead of 3.55. Thanks. On the axle, there's not enough difference between 3.54 and 3.55 to worry about as it won't change the needed driven gear at all. But if I remember correctly 3.54 is the ratio for a larger diff, like a Dana, and 3.55 is the ratio used on an 8.8 or 10.25 Sterling. The ratio has to do with the number of teeth you can get on the ring gear. An 8.8" doesn't have quite as much room as a 9", and since you have to have an integral number of teeth, it limits the ratios you can have. Link to comment Share on other sites More sharing options...
grumpin Posted December 2, 2018 Share Posted December 2, 2018 Thanks. On the axle, there's not enough difference between 3.54 and 3.55 to worry about as it won't change the needed driven gear at all. But if I remember correctly 3.54 is the ratio for a larger diff, like a Dana, and 3.55 is the ratio used on an 8.8 or 10.25 Sterling. The ratio has to do with the number of teeth you can get on the ring gear. An 8.8" doesn't have quite as much room as a 9", and since you have to have an integral number of teeth, it limits the ratios you can have. Thanks Gary! Link to comment Share on other sites More sharing options...
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