It's all about driveshaft revs/mile.
Stock revolutions are 2379.
(638 revs/mile for tire x 3. 73 gears=2379)
35" tires rotate 582. 4 times/mile. If I change the rear end ratio to 4. 1 I get 2388 driveshaft revolutions per mile. (4. 1 x 582. 4)
Sound right?
Diff gearing doesn't affect speedo on 3rd gens only tire size
Bob
did you guys have to deal with the tone ring when using smarty? with the dealer programmer it was the last entry/option. the dealer did mine and didn't know what to select when he got to the tone ring and just guessed. he's supposed look it up to give me a call with the correct size but is blowing me off now.
options were 9. 5 10. 5 and 11. 5 for tone ring. i thought it should match the axle (11. 5) but he went with 10. 5.
did some internet searches and found a little info that suggested different size tone rings came with automatics vice manual and 4. 11s vice 3. 73 and so on even though they are all 11. 5 axles. but couldn't pin down for sure what i have.
truck shifts a little differently now and it's driving me crazy that something could be programmed wrong with it... . damage?? the different shifting could just be from the 285/70/17 tire size they selected even though my tires are 295/70/17... a full inch taller.
does anyone know what i'm supposed to be at for tone ring?
jeff
So... I bought a Smarty today from tstproducts.com.
I sold my triple dog on eBay! TIM
Got the smarty Fri night, updated the software and completed the ECM and ABS update. Speedo shows correct speed (verified x gps) and truck moves out, and blows some smoke under heavy throttle. I like the smarty, and I'm convinced it's of better quality than the tri dog, but I wonder why it doesn't have the ability to change things like idle up option, fog light/high beam operation, seat belt minder, accessory delay?