342 diff in 99 a4
Burning Brakes
Joined: Mar 2003
Posts: 874
Likes: 0
From: Bonita CA
When going to 3:42 gears, you may want to get someone with a handheld tuner to reprogram your computer so it knows that it is there. This is required especially if your C5 came with 2:73s. Your C5 came with either 3:15 or 2:73 gears, so your speedometer will be wrong and some weird things happen when using the criuse control. A tranny cooler is always the better way to go! I have mine stand alone and not inline with the radiator cooler. My typical tranny fluid temp never exceeds 165*. When I run hard it may sometimes get to 175* on a hot day. Before I added the cooler, my temps went as high as 230*- thats hotter than your average motor oil temps! Also, almost all factory 3:42 carriers always leak! Not much, but they do leak!
Race Director
Joined: Jun 2004
Posts: 19,459
Likes: 48
From: Schaumburg IL
CI 7-8-9-11 Veteran
St. Jude Donor '06-'10, '13
The speedometer will still read correctly, the sensor is not off the gear itself like in other cars.
