3.73 gears GP by LAPD
Burning Brakes
Joined: Oct 1999
Posts: 1,041
Likes: 0
From: Charleston SC
Re: 3.73 gears GP by LAPD (L.A.P.D.)
Shawn-
I do not think that your information is correct. I have changed from the 3.42 rear end to the 3.73, and my speedometer is perfectly accurate and there are no codes. That is, the speedomenter will not be inaccurate on an M6 car after a gear change, for sure for the 2000 at least. The speedometer sensor measures the speed of one of the axle half shafts. The only thing that could change the speedo accuracy would be changing the tire diameter. Thus, because the primary vehicle speed sensor on the C5 is after the pinion gear (so it sees axle speed or differential output speed, not differential input speed), the speedometer calibration is not an issue on the manual transmission application.
For the auto cars, what you got from Getrag is correct, and a PCM reprogram is in fact necessary.
I do not think that your information is correct. I have changed from the 3.42 rear end to the 3.73, and my speedometer is perfectly accurate and there are no codes. That is, the speedomenter will not be inaccurate on an M6 car after a gear change, for sure for the 2000 at least. The speedometer sensor measures the speed of one of the axle half shafts. The only thing that could change the speedo accuracy would be changing the tire diameter. Thus, because the primary vehicle speed sensor on the C5 is after the pinion gear (so it sees axle speed or differential output speed, not differential input speed), the speedometer calibration is not an issue on the manual transmission application.
For the auto cars, what you got from Getrag is correct, and a PCM reprogram is in fact necessary.
Supporting Vendor
Joined: Feb 2000
Posts: 7,302
Likes: 1
From: Los Angeles, CA
St. Jude Donor '03-'04-'05-'06
Re: 3.73 gears GP by LAPD (George Cooper)
George Cooper,
I guess our rep at Getrag gave us the wrong info, but I will check with them again and make sure he knows that I am talking about a manual car.
Thanks!
Shawn
I guess our rep at Getrag gave us the wrong info, but I will check with them again and make sure he knows that I am talking about a manual car.
Thanks!
Shawn
