Axle Ratio...
#1
Burning Brakes
Thread Starter
Axle Ratio...
I have a 1986 coupe. I am trying to determine my axle ratio. I thought that all early vettes had a 2.59 rear. If I am reading my codes right it says 3.07 rear. On the window sticker it says performance axle ratio. On the build sheet it says 4YJ in the axle box. On the bottom of the build sheet it has code G44 3.07 ratio.
Any help would be appreciated.....
Any help would be appreciated.....
#2
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If you have the G92, G44 RPO you have the 3:07's if it's an auto.
#4
Burning Brakes
Thread Starter
Ratio
thanks....
Last edited by rrt898; 03-24-2014 at 12:55 PM.
#5
Team Owner
The code in the Box 11 is not an RPO code.
G44 denotes a 3.07 diff ratio and if the car is an auto trans, there should be a G92 code. G92 simply shows that a "Performance Axle" has been installed. The ratio used with that RPO code changes based on the body style and trans.
2.59 ratio was typically found in convertibles with an auto trans and standard axle ratio. My old '92 'vert with an A4 had the G92 option but the installed gearset was a 2.73, listed as RPO GU2.
G44 denotes a 3.07 diff ratio and if the car is an auto trans, there should be a G92 code. G92 simply shows that a "Performance Axle" has been installed. The ratio used with that RPO code changes based on the body style and trans.
2.59 ratio was typically found in convertibles with an auto trans and standard axle ratio. My old '92 'vert with an A4 had the G92 option but the installed gearset was a 2.73, listed as RPO GU2.
#6
Burning Brakes
Thread Starter
On the build sheet and the window sticker I see the G44 code for performance axle 3.07. I do not see the G92 code. I am pretty sure its a 3.07 from both sheets.
thanks...
thanks...
#7
Melting Slicks
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really need to get the rear wheels off the deck, chalk mark the rear wheels and the driveshaft, put trans in 'neutral', turn a wheel 'one' revolution while eyeballing driveshaft/count turnS (forget trying to turn the driveshaft by hand as the c-beam will enjoy your knuckle sandwich).
if your car has a manual trans, learn d36 vs d44 faces, verify yours, some 'persons' have 'fixed' a d44 by swapping in a d36 (d44 worth 2-3 x what d36 brings)
if your car has a manual trans, learn d36 vs d44 faces, verify yours, some 'persons' have 'fixed' a d44 by swapping in a d36 (d44 worth 2-3 x what d36 brings)
#8
Burning Brakes
Thread Starter
Axle
really need to get the rear wheels off the deck, chalk mark the rear wheels and the driveshaft, put trans in 'neutral', turn a wheel 'one' revolution while eyeballing driveshaft/count turnS (forget trying to turn the driveshaft by hand as the c-beam will enjoy your knuckle sandwich).
if your car has a manual trans, learn d36 vs d44 faces, verify yours, some 'persons' have 'fixed' a d44 by swapping in a d36 (d44 worth 2-3 x what d36 brings)
if your car has a manual trans, learn d36 vs d44 faces, verify yours, some 'persons' have 'fixed' a d44 by swapping in a d36 (d44 worth 2-3 x what d36 brings)
I was thinking the same thing. I'll jack up the car and make sure. I have no need for D44. The car doesn't go to the track.
thanks
#9
Team Owner
The D36 differential came on all cars with an auto trans. The D44 came with all manual transmission cars.
The D44 is stronger, but it won't make any difference for street use.
I meant to say that the early C4's didn't show a G92 as a "Performance Axle". The G44 is the code for the 3.07 as you see. Only the later C4's with RPO G92 will show an additional code for a specific gear ratio.
Does your car have the 4+3 manual trans? The standard axle ratio for manual cars is a 3.07.
The D44 is stronger, but it won't make any difference for street use.
I meant to say that the early C4's didn't show a G92 as a "Performance Axle". The G44 is the code for the 3.07 as you see. Only the later C4's with RPO G92 will show an additional code for a specific gear ratio.
Does your car have the 4+3 manual trans? The standard axle ratio for manual cars is a 3.07.
#10
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G44 is 3.07, G92 is a performance axle option that specified 3.07 gearing, but they are not one and the same.
#11
Race Director
My window sticker does not specify a performance axle option. I know it has a 3.07 because I remember asking about it when I ordered the car. Also it has the BUA EPROM in the ECM, which is for the 3.07 axle ratio with auto trans.
Maybe the 3.07 ratio was part of the Z51 option, which I do have.
Maybe the 3.07 ratio was part of the Z51 option, which I do have.
#12
That is the way your car was built and you don't ever mention it but I'd say your car is an A4 and NOT an MT.
#14
Melting Slicks
Z51 gets you a 3.07 rear in '86.
#15
Burning Brakes
Thread Starter
#16
Melting Slicks
My car is bone stock. But for a little more boulevard zip I am considering a 3.54 gear swap. I do not drive it on many long trips.
#17
Burning Brakes
Thread Starter
I built a 3.55 a couple years ago but; I didn't install it because I was a little nervous about the big change. That's when I thought I had a 2.59. Now that I know I have a 3.07 I'm going to install the 3.55. I even changed the speedometer gears in the trans for a 3.55.