Gary Lewis Posted November 9, 2017 Share Posted November 9, 2017 Gary, it looks like I will indeed need some kind of ratio adjuster when I go to the larger wheels and tires... but in the meantime if I use an 8 tooth drive and 16 tooth driven gear the speedometer should read exactly right (current tires measure 30"). As much of a horrible pain in the butt as it would be, I might even try to find a junkyard gear. I don't want to get too invested in this whole thing because I may switch transfer cases and add the overdrive later. If that happens I will need the drive gear that fits the overdrive, not the TC. Both Gear Vendors and Doug Nash use GM parts so I will be starting over. The ratio adjusters are a little pricey so if I buy one I want it to jive with the OD unit. 🙄 Interesting. I get that you'll be indicating 61.916 @ a true 60.000 MPH. But, that's close enough for me. Anyway, maybe you can get it going with soon and it'll work w/your current tires. And then, as you said, when you do the O/D do the tires at the same time and adapt to that. Link to comment Share on other sites More sharing options...
Ford F834 Posted November 9, 2017 Author Share Posted November 9, 2017 Interesting. I get that you'll be indicating 61.916 @ a true 60.000 MPH. But, that's close enough for me. Anyway, maybe you can get it going with soon and it'll work w/your current tires. And then, as you said, when you do the O/D do the tires at the same time and adapt to that. Gary, in your calculators you have 3.07 entered as the final drive ratio. My rear axle is 3.00 so that's probably where the variance is coming from. Link to comment Share on other sites More sharing options...
Gary Lewis Posted November 9, 2017 Share Posted November 9, 2017 Gary, in your calculators you have 3.07 entered as the final drive ratio. My rear axle is 3.00 so that's probably where the variance is coming from. Good catch. With 3.00 I get 60.504. Link to comment Share on other sites More sharing options...
Ford F834 Posted November 9, 2017 Author Share Posted November 9, 2017 Good catch. With 3.00 I get 60.504. That's what I get and it will work for me if I can find the gears! Link to comment Share on other sites More sharing options...
Gary Lewis Posted November 9, 2017 Share Posted November 9, 2017 That's what I get and it will work for me if I can find the gears! I can't find that gear either. But I submitted a question to Midwest Transmissions to see if they have it. They don't show to even have parts for the 1345, but they do for the 1356. In fact they have an 8-toothed gear for the 1356, but it is brown. Link to comment Share on other sites More sharing options...
PetesPonies Posted November 10, 2017 Share Posted November 10, 2017 That's what I get and it will work for me if I can find the gears! No ratio adjuster needed, thats where the simple linear math is used. But I need a starting point. You need to drive the vehicle with a working speedo . . and know which driven gear you have in place. Link to comment Share on other sites More sharing options...
Gary Lewis Posted November 10, 2017 Share Posted November 10, 2017 No ratio adjuster needed, thats where the simple linear math is used. But I need a starting point. You need to drive the vehicle with a working speedo . . and know which driven gear you have in place. Pete - That’s just the point. The speedo doesn’t work and it appears it is the drive gear. So he’s just figuring out what gear he needs. Unfortunately it looks like one that is hard to find. Link to comment Share on other sites More sharing options...
1986F150Six Posted November 15, 2017 Share Posted November 15, 2017 I can't find that gear either. But I submitted a question to Midwest Transmissions to see if they have it. They don't show to even have parts for the 1345, but they do for the 1356. In fact they have an 8-toothed gear for the 1356, but it is brown. Would this work? http://dennis-carpenter.com/speedometer-drive-gear/p/E0TZ-17285-B/ Link to comment Share on other sites More sharing options...
Gary Lewis Posted November 15, 2017 Share Posted November 15, 2017 I can't find that gear either. But I submitted a question to Midwest Transmissions to see if they have it. They don't show to even have parts for the 1345, but they do for the 1356. In fact they have an 8-toothed gear for the 1356, but it is brown. Would this work? http://dennis-carpenter.com/speedometer-drive-gear/p/E0TZ-17285-B/ David - I did a search for the one Jonathan thinks he needs, E1TZ-17285-A, and got the same one and thought yippee! And then I realized it is E0TZ-17285-B. 😩 A few months ago I wouldn’t have had a clue why you can do a “verbatim” search for “E1TZ-17285-A” and find E0TZ-17285-B. But now that I’ve been trying to boost the search results of this website I know - someone put E1TZ-17285-A in the meta data for the page, so that’s what Google thinks is on the page. 😡 I’m going to call Dennis Carpenter and complain because those part numbers don’t interchange. Further, they show the application as for all 1980-86 trucks. But there are 9 other gears for those trucks, so that is inaccurate. Link to comment Share on other sites More sharing options...
Ford F834 Posted November 15, 2017 Author Share Posted November 15, 2017 I can't find that gear either. But I submitted a question to Midwest Transmissions to see if they have it. They don't show to even have parts for the 1345, but they do for the 1356. In fact they have an 8-toothed gear for the 1356, but it is brown. Would this work? http://dennis-carpenter.com/speedometer-drive-gear/p/E0TZ-17285-B/ Unfortunately Gary is right, that gear won't fit the transfer case. The 1345 takes a type 12 gear: I actually went into the Cottonwood Ford dealer today rather than just the phone call. The guy searched dealerships nation wide and it is unobtanium. Looks like I will have to junkyard it or install one of my overdrives and hope I have better luck sourcing those drive gears. 🙄 Thank you David, for helping me look! Link to comment Share on other sites More sharing options...
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