need help chosing gears
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Joined: Feb 2009
Posts: 81
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From: Grand Island New York
need help chosing gears
what you guys think i should get for my 2002 a4? i'm looking at 3.73 or maybe 3.90 but dont know if i should buy the differential or just the gears and have them installed. what do you think is the best way to do it and what is a good site to buy from? does anyone know what they will do to my top speed. car is mostly stock. long tubes and intake.
Pro
Joined: Oct 2008
Posts: 645
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From: Hayward Wi
http://forums.corvetteforum.com/c5-t...90s-4-10s.html
read that. will help u an lot
3.90s will decrease speed but increase acceleration in the first few gears as for in 5th gear i couldn't say
read that. will help u an lot
3.90s will decrease speed but increase acceleration in the first few gears as for in 5th gear i couldn't say
Pro
Joined: Oct 2008
Posts: 645
Likes: 1
From: Hayward Wi
look at this to http://forums.corvetteforum.com/c5-t...l-economy.html
as for your question of whole new rear end or gears id go with what seems cheaper i personally would go with the cheaper solution
as for your question of whole new rear end or gears id go with what seems cheaper i personally would go with the cheaper solution
Last edited by PuddleJumper; Mar 12, 2009 at 11:59 PM.
Thread Starter
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Joined: Feb 2009
Posts: 81
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From: Grand Island New York
i was wondering if anyone had a good site they like to order gears from. zip products sells 3.90 ring and pinion that will fit in the 2.73 carrier. any one else make that or 3.73's that will fit?
Thread Starter
Advanced
Joined: Feb 2009
Posts: 81
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From: Grand Island New York
i'd like 3.73's but i cant find any that fit in my stock 2.73 carrier.... would i be better off getting a differential already built or buying ring and pinion and having them installed by a shop? how hard is it to change a differential on my 02 a4?
Le Mans Master
Joined: May 2006
Posts: 7,802
Likes: 205
From: Hillsboro OR
Changing the ring and pinion is a HUGE undertaking. I didn't want to attempt it. I just bought the full carrier (w 3:42 gears) from DTE Powertrain. I was leary about going to 3:73's from the 2:73 as mine is a DD. The 3:42's made this feel like a completely different car. 
Melting Slicks
Joined: Feb 2006
Posts: 2,172
Likes: 103
From: Des Moines Iowa
http://forums.corvetteforum.com/c5-t...90s-4-10s.html
read that. will help u an lot
3.90s will decrease speed but increase acceleration in the first few gears as for in 5th gear i couldn't say
read that. will help u an lot
3.90s will decrease speed but increase acceleration in the first few gears as for in 5th gear i couldn't say
Read O/P again. It's an A4, there is NO 5th gear
It's my understanding you can't install the lower gears in your 2.73 housing. Even if you could, and you can't, it's better to buy the entire differential, already assembled from all that I've read
Pro
Joined: Oct 2008
Posts: 645
Likes: 1
From: Hayward Wi
an little note here
with the 3.73s your engine is going to spin faster. thus increasing oil temp and u will probably see an need to chance oil quicker but with 3.73s it wont be to bad but u will see it an little. another thing to think about here is gas millage 3.73s will make your gas millage go down some. but its up to you
i agree on the getting new reared it might be an good idea to get an whole new one so if you don't like the 3.73's you will have an ezer time changing them back to the OEM gears
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Melting Slicks
Joined: Mar 2004
Posts: 2,149
Likes: 6
From: NCCO Oklahoma
Check this out:
I have done gear work before. I swapped out my 4.10's in my Dana 60 for a set of 4.88's and it took a lot of time... even with the right tools.
The C5 rear end is a different animal all together. It requires a special tool kit that costs about a grand, if memory serves correctly. It's not something that your average enthusiast would want to tackle. Hell, it's not something that your local dealer or even an experienced mechanic would want to deal with.
More often than not, you trust that work to the Pros that are experienced in that unit. DTE has been mentioned, and they have a great reputation. I'm sure there are others if you look around a bit.
As you can see in the chart, a 3.42 with an auto is a good choice for a car that is driven around town and on the highway. If you are going to go racing, then a 3.73 or deeper gearset will get you gobs of acceleration... but highway manners may suffer. (As would your gas mileage... but who cares if you are focused on speed? )
Good luck with your decision.
Mark
I have done gear work before. I swapped out my 4.10's in my Dana 60 for a set of 4.88's and it took a lot of time... even with the right tools.
The C5 rear end is a different animal all together. It requires a special tool kit that costs about a grand, if memory serves correctly. It's not something that your average enthusiast would want to tackle. Hell, it's not something that your local dealer or even an experienced mechanic would want to deal with.
More often than not, you trust that work to the Pros that are experienced in that unit. DTE has been mentioned, and they have a great reputation. I'm sure there are others if you look around a bit.
As you can see in the chart, a 3.42 with an auto is a good choice for a car that is driven around town and on the highway. If you are going to go racing, then a 3.73 or deeper gearset will get you gobs of acceleration... but highway manners may suffer. (As would your gas mileage... but who cares if you are focused on speed?
)Good luck with your decision.
Mark
Racer
Joined: Nov 2008
Posts: 279
Likes: 2
From: Cabot Arkansas
I have an a4 99 convertible. It had 3.15 gears and I had it changed out at the dealership with 3.73's. They did it in the original housing. they already had the tranny out and only charged me another $1000 to do the swap and the new gears were heat treated and polished but I don't know what brand they used. The RPM change was very tolerable and the fuel mileage did not change that much. I get 23 mpg with mostly hwy where i was getting 25 before and the rpm at 70 mph is around 2350. The only problem is its twice has hard to get the smile off my face when I get back from driving. It's like driving a whole different car !!! I think it's the best mod you can make.
Thread Starter
Advanced
Joined: Feb 2009
Posts: 81
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From: Grand Island New York
I have an a4 99 convertible. It had 3.15 gears and I had it changed out at the dealership with 3.73's. They did it in the original housing. they already had the tranny out and only charged me another $1000 to do the swap and the new gears were heat treated and polished but I don't know what brand they used. The RPM change was very tolerable and the fuel mileage did not change that much. I get 23 mpg with mostly hwy where i was getting 25 before and the rpm at 70 mph is around 2350. The only problem is its twice has hard to get the smile off my face when I get back from driving. It's like driving a whole different car !!! I think it's the best mod you can make.
Team Owner
Joined: Jul 2004
Posts: 24,652
Likes: 298
From: NJ
St. Jude Donor '05-'08
buy a new Z06 carrier with 3.42 gears. Most people love that combination in their cars.
We charge $1749 for parts, the install and reprogramming the shift points.
http://www.eastcoastsupercharging.com/Gears.html
We charge $1749 for parts, the install and reprogramming the shift points.
http://www.eastcoastsupercharging.com/Gears.html
Racer
Joined: Nov 2008
Posts: 279
Likes: 2
From: Cabot Arkansas
It included the gears but not the labor for removing the transmission and associated parts which would probably add another 1200 dollars at the dealership. It also did not include the needed reprogramming but I already had a Predator I used for that.
Last edited by spdracr39; Mar 14, 2009 at 07:20 PM. Reason: addinfo
Thread Starter
Advanced
Joined: Feb 2009
Posts: 81
Likes: 0
From: Grand Island New York
buy a new Z06 carrier with 3.42 gears. Most people love that combination in their cars.
We charge $1749 for parts, the install and reprogramming the shift points.
http://www.eastcoastsupercharging.com/Gears.html
We charge $1749 for parts, the install and reprogramming the shift points.
http://www.eastcoastsupercharging.com/Gears.html
Racer
Joined: Oct 2005
Posts: 435
Likes: 0
From: Northern California
if you are looking for some fun accel and to dd the car then i would also add a stall. dave at yanks said that they built the ss3600 stall to work with the 3.42 gears. they are a blast and very streetable. and if you are mechanically inclined and have the tools then i would say you should do it yourself. i blew away 3 bolt on modded z06's at the track on street tires with that set up.
Team Owner
Joined: Jul 2004
Posts: 24,652
Likes: 298
From: NJ
St. Jude Donor '05-'08
Burning Brakes
Joined: Feb 2009
Posts: 1,192
Likes: 7
From: Charlotte N.C
Last year at carisle, my friend picked up a 3:42 unit complete for 400.00
He works at a dealership so after work the corvette guy pulled 273 out, servided and checked out the 342,,and now my friend says his car feels and spins like a new beast.
He works at a dealership so after work the corvette guy pulled 273 out, servided and checked out the 342,,and now my friend says his car feels and spins like a new beast.
Thread Starter
Advanced
Joined: Feb 2009
Posts: 81
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From: Grand Island New York
^^^ i would love to get a deal like that. i will add a stall. i like to drag race. nothing real serious. i just bought a n20 kit. still considering 3.73 but if the price is right i will grab some 3.42. thanks for the help everyone
Le Mans Master
Joined: May 2006
Posts: 7,802
Likes: 205
From: Hillsboro OR
Mine is a DD. When I had the 2:73 in there I could barely "break em loose" even with the very hard runflats. Now with the 3:42 and a stall installed I can smoke them from a standstill. On a hard launch, the tires break loose during the 1 - 2 shift, during the 2 - 3 shift. It is a completely different car.
Going to the 3:42's only lost me an average ~1 - 2 mpg. This is by far THE BEST mod you can do for a Coupe.
Going to the 3:42's only lost me an average ~1 - 2 mpg. This is by far THE BEST mod you can do for a Coupe.