viven44 Posted July 31 Author Share Posted July 31 Just get a measure from the center of the hub to the ground and use that number. Definitely if you force too wide a tire on a rim, and it has some cheesy 2 ply passenger rating it's going to distort and overheat. There's a reason for the difference between P rated & LT radials Ok the speedo is happy now. I had to lop off another 1/4 inch of the inner cable..... I had already cut a good 1/2 inch off on the driven gear side... There was still some built in stress I guess from it being too long so it was binding on me. It was bad... but I didn't register that it didn't register anything until about 10mph. Between 50-70mph, it was bouncing around so I was basically getting a root-mean-square input to the odometer Maybe i'm slightly better than 7mpg after all Link to comment Share on other sites More sharing options...
viven44 Posted August 7 Author Share Posted August 7 Ok the speedo is happy now. I had to lop off another 1/4 inch of the inner cable..... I had already cut a good 1/2 inch off on the driven gear side... There was still some built in stress I guess from it being too long so it was binding on me. It was bad... but I didn't register that it didn't register anything until about 10mph. Between 50-70mph, it was bouncing around so I was basically getting a root-mean-square input to the odometer Maybe i'm slightly better than 7mpg after all While the speedo was happy it wasn't perfect at high speeds like the one on Big Blue 2WD... I still had troubles over 60mph (live able but I wasn't happy). Just until this morning... when I went to work. Swapped the LMC driven gear with OEM Ford driven gear CODD-17271-B today and drove 60 miles on the highway for an errand... I wanted the gear swap done before leaving so I got a good test run. Zero issues. Not even once did it want to jump or wander.... It is as good as Big Blue 2WD now... no doubts. I say it was a case of LMC cheap driven gear that took me in circles and made me do so many things. Strike 3 against LMC... I got carried away into buying too much LMC junk for this Bronco build. I can't even visually tell the difference to be honest. The OEM gear has R and 18 marked on it and the LMC one had no markings but obviously there are differences in tolerances of the teeth possibly. Both of them were the same cost as well If only Ford still made / contracted all the parts for these old trucks no one would need to buy new vehicles!! Link to comment Share on other sites More sharing options...
BigBrother-84 Posted August 8 Share Posted August 8 If only Ford still made / contracted all the parts for these old trucks no one would need to buy new vehicles!! Touché. How do you call this in English, a "truism"? It's the sole and only thing that motivates their jobs. Sale new vehicles. Link to comment Share on other sites More sharing options...
viven44 Posted August 8 Author Share Posted August 8 If only Ford still made / contracted all the parts for these old trucks no one would need to buy new vehicles!! Touché. How do you call this in English, a "truism"? It's the sole and only thing that motivates their jobs. Sale new vehicles. I think Touché is probably the word in english as well in the urban circles, lol In more local country circles... maybe "hell yeah" .. definitely not "bless your heart" Link to comment Share on other sites More sharing options...
BigBrother-84 Posted August 9 Share Posted August 9 I think Touché is probably the word in english as well in the urban circles, lol In more local country circles... maybe "hell yeah" .. definitely not "bless your heart" «Touché» means "right in the bullseye Man", so yep "hell yeah" does the job for sure! You hit the nail on the head Vivek, Hell Yeah! Yee-Haw! Link to comment Share on other sites More sharing options...
viven44 Posted August 23 Author Share Posted August 23 Just get a measure from the center of the hub to the ground and use that number. Definitely if you force too wide a tire on a rim, and it has some cheesy 2 ply passenger rating it's going to distort and overheat. There's a reason for the difference between P rated & LT radials Jim, I owe you an apology. I installed the NOS speedo drive gear today D5TZ-17285-A and I have about a 10-15% error now (Speedo shows 40, I'm actually going ~35) because the old gear was practically bald. The new one is driving the driven gear a bit more. Any way you had mentioned the other day that I should measure the radius from center to ground and I had sort of not done that as I knew I was sure what I had was 31" tires and figured if I was off, it would be negligible as the tires looked round, but I am measuring only 14.25 from the ground so the effective diameter is only 28.5 in my case.... If I had paid closer attention to the chart you send, I would have noticed that depending on whether the application is highway or mud/snow/all-terrain, the highway variants always have a smaller driven gear as the effective tire diameter is likely larger. I am off to changing my driven gear from 18 teeth to perhaps 19 or 20 teeth to get the speedometer more accurate based on the measured tire diameter. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted August 23 Share Posted August 23 Jim, I owe you an apology. I installed the NOS speedo drive gear today D5TZ-17285-A and I have about a 10-15% error now (Speedo shows 40, I'm actually going ~35) because the old gear was practically bald. The new one is driving the driven gear a bit more. Any way you had mentioned the other day that I should measure the radius from center to ground and I had sort of not done that as I knew I was sure what I had was 31" tires and figured if I was off, it would be negligible as the tires looked round, but I am measuring only 14.25 from the ground so the effective diameter is only 28.5 in my case.... If I had paid closer attention to the chart you send, I would have noticed that depending on whether the application is highway or mud/snow/all-terrain, the highway variants always have a smaller driven gear as the effective tire diameter is likely larger. I am off to changing my driven gear from 18 teeth to perhaps 19 or 20 teeth to get the speedometer more accurate based on the measured tire diameter. I certainly don't need an apology, I was just surmising why your speedometer was off, and radius was the thing that made sense to me. Anyway, I hope changing the gear gets you a lot closer to ideal, and your mileage on track. Link to comment Share on other sites More sharing options...
viven44 Posted August 31 Author Share Posted August 31 I certainly don't need an apology, I was just surmising why your speedometer was off, and radius was the thing that made sense to me. Anyway, I hope changing the gear gets you a lot closer to ideal, and your mileage on track. After using the correct driven/drive gear combination, the speed calibration is good, especially at high speed. Now my gas mileage is 8.5mpg in city, up from around 7mpg. Not a far cry from the 11.5mpg my wife gets in the city with her brand new 'LS' with all the fancy DFM and 10 speed trans Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted August 31 Share Posted August 31 After using the correct driven/drive gear combination, the speed calibration is good, especially at high speed. Now my gas mileage is 8.5mpg in city, up from around 7mpg. Not a far cry from the 11.5mpg my wife gets in the city with her brand new 'LS' with all the fancy DFM and 10 speed trans Your Edelbrock won't destroy the engine in 45,000 miles. Link to comment Share on other sites More sharing options...
viven44 Posted September 1 Author Share Posted September 1 Your Edelbrock won't destroy the engine in 45,000 miles. Yes indeed!! I spoke to the dealers about installing a DFM disable dongle, but apparently that can void the warranty. Well my wife was well advised of the perils of too much technology and my recommendation was to find a pre-2007 low mileage suburban but that wasn't reassuring from a "drive anywhere" standpoint to her. She choose what to play with... for 3 years I don't have to worry about anything. For 5 years I don't have to worry about powertrain. After that I am on my own.. and not really sure how well I can service most things. Heck there is no transmission dipstick and changing transmission fluid requires removal of exhaust from both manifolds, at least there is an engine oil dipstick but that will be gone soon too I'm sure in newer models. Link to comment Share on other sites More sharing options...
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