Gears in 99 C5 auto
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From: Rochester Hills Mich
Gears in 99 C5 auto
Hello, My b-inlaw is looking into buying a 99 C5. This car has I think a 2.7 gear in the rear. He wants to buy the car and put a 3.7 into it. He was told that its not just a gear change that there is some other things that have to be changed. Also that it would almost cost 2k. Is this true?
Racer
Joined: Apr 2005
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From: Lenoir Tn
Gears
If he has a 273 which is stock and you go to a 373 he will get a lot more punch on low end however his rpms on the road will be high. He will also loose some gas milege. It all depends on what he want to do. If he is going to race the car or just want a little more punch. If he's not going to race the car I would suggest changing the 273 to a 315 or 342 not a 373.
Advanced
Joined: Aug 2004
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From: midland tx
he will probably need to get the the computer reprogramed to get the shift points correct in the trans. as for the price of the job its hard to say. i paid over 2000 for my rear diff from dte and installed it myself. it just depends on what your getting for the money. ie cryo treating, harden shafts, polished gears.
Team Owner
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From: S.W. Ohio. . . . . . NRA Life Member
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If he has 2.73 gears he should contact DTE who is a forum sponsor. They can converter the 2.73 carrier to 3.42 or 3.73 gears. If you really want much better performance he should also consider swapping the stock T/C while the car is apart for the rear end swap.
IMO he should install at least 3.42 gears. If he doesn't do a lot of cruising at 80+ MPH 3.73 gears would be even better.
IMO he should install at least 3.42 gears. If he doesn't do a lot of cruising at 80+ MPH 3.73 gears would be even better.
Last edited by C5magic; Apr 30, 2005 at 07:44 AM.
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From: Putting a 50¢ sticker of the U.S. Flag on a $50,000 import does not make one a patriot.
Originally Posted by C5magic
If he has 2.73 gears he should contact DTE who is a forum sponsor. They can converter the 2.73 carrier to 3.42 or 3.73 gears..
But DTE is not making any 3.73's right now. The company who makes the 3.73 ring and pinion made a bad batch of them, and they have been all recalled. The do have 3.42's and 3.90's.
The only way to get a 3.73 right now is by ordering a new Getrag unit. Which is what I did, from a forum sponsor.
You friend will need to reprogram the PCM for the different gears. He could use LS1 edit, HP Tuners, or a custom Predator tune. The Predator will not do the gear scaling out of the box for his year, he would need to contact Diablo Sport.
Good Luck,
AZC5
