J Christensen

I have an 09 LT3 base coup w/NAV and NPP. It has the tour/sport ****. How can I tell the differential gearing and if it has the Z1 package?

Thank you.

roscoe118

No "Z1" package... Do you mean Z51? If you have the Tour/Sport ****, then you have the F55 suspension. It is not the same as Z51, but I believe has Z51 brakes. Does it have slotted rotors? My wife's '08 3LT/F55 Coupe has slotted rotors (Z51 brakes).

Is it manual or auto? If it is manual you have 3.42 gearing. If it is auto you have either 2.56 or 2.73. Not sure how to tell the difference. Hopefully, someone that does will chime in.

boraxman

Sounds like f55...Throw some z51 sway bars on there...

As said Differential gearing is surely 3.42 if you have a manual trans.

Corvette Junkie

Neither the Z51 or F55 had slotted rotors. They did have drilled rotors.

Gearhead Jim

When you open the glove box, there is a sticker on the left side that lists all the features and option codes of your particular car. Try to copy them down without twisting your neck (I took a photo and copied mostly from there), and you should be able to find the code list in Google. Or some kind person here might post a link to it.

You can also get a copy of the build sheet and window sticker, from the NCM for a modest fee. Nice to have if your originals are missing.

J Christensen

Roscoe,

Thank you. It is an auto. I'm not sure about the rotors - I'll check again.

J Christensen

Jim,

Thank you. More good info. I'll go search it.

HOXXOH

'09' A6 base suspension and F55 cars were available with either the standard 2.56 or the optional 2.73 axle. There is a sticker on the back of the dif with the ratio that can easily be seen between the mufflers. The A6 Z51 cars had the 2.73 as standard.

Most of the factory build codes on the glovebox sticker can be interpreted from information on the corvetteactioncenter.com site on the specs page. The 2.56 is GM8, while the 2.73 is GU2.