Installing new ring and pinion. speedo sensor question
Thread Starter
Racer
Joined: Aug 2014
Posts: 478
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From: Elizabethtown, NC
Installing new ring and pinion. speedo sensor question
Hello. I am in the process of installing a Motive ring and pinion in my 2006 M6 differential. This is going in my 2005 C6 coupe. In my 2005 diff the ring gear has cogs that line up with the speedo sensor in the hole. Now this 2006 diff I bought does not have these cogs on the original ring gear and the speedo sensor lines up with the teeth. When I ordered the new Motive gears, they have the cogs. So I am guessing the 2006 diff sensor read off the teeth. Is this so? Seems weird to me. I hope I made sense.
Thread Starter
Racer
Joined: Aug 2014
Posts: 478
Likes: 66
From: Elizabethtown, NC
Race Director
Joined: Aug 2005
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From: Hudson WI
NCM Sinkhole Donor
Maybe not on an 05, but I almost positive on an 06 or newer. 05 has a different computer than an 06. When I went from 3:42 to 3:73 they told me they had to do it, but it was a few years ago, so I may be mistaken.
Race Director
Joined: Aug 2005
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From: Hudson WI
NCM Sinkhole Donor
So how does it know that the gear ratio changed and adjust accordingly? Not a statement, but a question. Does it use the wheel sensors?
See post #5 from RPM.
https://www.corvetteforum.com/forums...ear-gears.html
See post #5 from RPM.
https://www.corvetteforum.com/forums...ear-gears.html
Last edited by timd38; Sep 7, 2015 at 08:42 PM.
Race Director
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From: Bay Area Ca.
So how does it know that the gear ratio changed and adjust accordingly? Not a statement, but a question. Does it use the wheel sensors?
See post #5 from RPM.
https://www.corvetteforum.com/forums...ear-gears.html
See post #5 from RPM.
https://www.corvetteforum.com/forums...ear-gears.html
See post #7 by Joe G.
Tech Contributor
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From: St. Louis, MO
St. Jude Donor '08
Autos must have their tunes changed when gear ratios change as the transmission shift points are based on rpm and speed and those ratios change, obviously, when the gear ratio changes. C5's and 05 C6's with reluctor wheels don't need to change the tune in a manual car when the gears are changed.
Dentalfloss I've been racking my brains to remember if there is any problem going from the 05 with a reluctor to later with no reluctor. This goes back a long time and I"m not 100% positive but I THINK you do need to change your VSS pulses per mile when going from the 05 with the reluctor to the new diff that reads VSS pulses off the ring gear. Obviously there are a lot more pulses on the ring gear than the reluctor per mile.
You can verify what I'm saying by looking at a stock 05 tune for VSS pulses and then an 06. If my memory is right, I'd copy the 06 VSS per mile as a start, then, use a speedometer app on your phone to fine tune your speedometer by adjusting the VSS pulses per mile.
Dentalfloss I've been racking my brains to remember if there is any problem going from the 05 with a reluctor to later with no reluctor. This goes back a long time and I"m not 100% positive but I THINK you do need to change your VSS pulses per mile when going from the 05 with the reluctor to the new diff that reads VSS pulses off the ring gear. Obviously there are a lot more pulses on the ring gear than the reluctor per mile.
You can verify what I'm saying by looking at a stock 05 tune for VSS pulses and then an 06. If my memory is right, I'd copy the 06 VSS per mile as a start, then, use a speedometer app on your phone to fine tune your speedometer by adjusting the VSS pulses per mile.
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Race Director
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From: Hudson WI
NCM Sinkhole Donor
Not sure what is correct.
I called the guy that put mine in and he said that every 06 to 12 Corvette that they have put gears into, had to have the speedo calibrated.
Last edited by timd38; Sep 8, 2015 at 10:36 AM.
Thread Starter
Racer
Joined: Aug 2014
Posts: 478
Likes: 66
From: Elizabethtown, NC
Autos must have their tunes changed when gear ratios change as the transmission shift points are based on rpm and speed and those ratios change, obviously, when the gear ratio changes. C5's and 05 C6's with reluctor wheels don't need to change the tune in a manual car when the gears are changed.
Dentalfloss I've been racking my brains to remember if there is any problem going from the 05 with a reluctor to later with no reluctor. This goes back a long time and I"m not 100% positive but I THINK you do need to change your VSS pulses per mile when going from the 05 with the reluctor to the new diff that reads VSS pulses off the ring gear. Obviously there are a lot more pulses on the ring gear than the reluctor per mile.
You can verify what I'm saying by looking at a stock 05 tune for VSS pulses and then an 06. If my memory is right, I'd copy the 06 VSS per mile as a start, then, use a speedometer app on your phone to fine tune your speedometer by adjusting the VSS pulses per mile.
Dentalfloss I've been racking my brains to remember if there is any problem going from the 05 with a reluctor to later with no reluctor. This goes back a long time and I"m not 100% positive but I THINK you do need to change your VSS pulses per mile when going from the 05 with the reluctor to the new diff that reads VSS pulses off the ring gear. Obviously there are a lot more pulses on the ring gear than the reluctor per mile.
You can verify what I'm saying by looking at a stock 05 tune for VSS pulses and then an 06. If my memory is right, I'd copy the 06 VSS per mile as a start, then, use a speedometer app on your phone to fine tune your speedometer by adjusting the VSS pulses per mile.
Race Director
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From: Bay Area Ca.
As always I could be wrong.
Funny thing is I remember chasing this question 7 years ago and got mixed answers then too. My shop said nothing needed to be changed, not sure if this included anything in the tune but as I understand nothing in the way of a part change. I recall now that DTE Engineering told me the same thing prior to purchasing their complete rebuilt differential.
Last edited by Boomer111; Sep 8, 2015 at 08:52 PM.
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St. Jude Donor '15
I just looked at a stock 05 vs stock 06 file and the VSS pulses per rev. are almost the same (40 vs 41)
Pulses per mile under "PCM output calibration" were 30,828 and 31,599 for 05/06 respectively
"VSS tire revs per dist" were identical at 479 per km
Pulses per mile under "PCM output calibration" were 30,828 and 31,599 for 05/06 respectively
"VSS tire revs per dist" were identical at 479 per km