Just got a low mileage 2002 convertible, nicely optioned. I knew from this site to check the door RPO code but crosschecking the site below, I don't see a RPO code to indicate the Torsen limited slip differential:

Chevy Camaro RPO Codes

I read elsewhere that GU80 indicated the l.s.d. but that neither appears on my door or within the 2002 RPO codes. The car does have the 3.42 (GU6) and 4-wheel discs (J65). Is there a different code other than GU80 that I should look for?

And I know the other way is to go out and try some burnouts and see if it leaves one or two black marks.

 

Put both rear wheels up off the ground. Put transmission in park or first gear, depending on transmission. Turn one of the rear wheels clockwise. If you have an open diff the opposite wheel will turn in the opposite direction. More useful would be to pull the rear cover and see what lurks underneath, and at the same time change the rear end lubricant. Also at this time take the opportunity to count the teeth on the pinion and ring gears & see what the real ration is, just in case changes were made.

 

What he said. Also the code is gu8 not gu80. It would say gu6 then the next code would be gu8 if you had limited slip. Or you can do a long burnout. If you start with 2 strips but it goes to one shortly after you have an open carrier. If you have to strips the whole burn out you have limited slip.

 

dont all the V6 cars have an open diff???

 

Nope. You can order them with limited.

 

go to this site

Comprehensive Chevrolet, Saturn, GMC, Hummer, Cadillac, Buick, Oldsmobile, Pontiac, Geo, Dodge, Plymouth, Jeep, Chrysler, Ford, Lincoln, Mercury, Mazda Truck, Mercedes VIN Decoder

and put your VIN in the box and it will give you a list of all your RPOs and what they mean. IF you have the LSD then it will be listed. You to have the Torsen diff but it could be open or LSD with a V6. Almost all z28s came with the LSD but almost all V6s didn't.

Massey

 

Thanks everyone. I double checked my door codes against the VIN decoder Massey linked to, as well as this one:

Chevy Camaro RPO Codes

The catalog for 2002 indicates that for the V6s, the Torsen diff was available as part of the Y87 perf option, which also included the fast ratio steering rack and dual outlet exhaust.

http://www.35thle.com/images/cam_catalog.pdf

I didn't lift the rear end up and do the rotation test z28pete suggested, but it is apparent this vehicle has an open diff. Even with 'just a v6,' its pretty easy to launch and make the right rear spin. There doesn't seem much point to any other mods until I can put the existing power to the ground.

Since I already have rear discs, it seems like overkill to replace the entire axle. Guess I need to read up on swapping out the differential. Am I looking at ordering an Auburn or Detroit Locker unit from Jegs that fits the 28-spline 7.5" rear end and doing this on a weekend in my garage? What's the level of difficulty?

 

It's not that bad unless you change gears. You need to pull the tires off undo your calipers and remove your rotors. Then open up your diff case and pull the axle pins and clips. Then slide the axles out and pull the carreir out and remove the gears.
Now if you have asr (traction control) you need to remove the sensor that is above each axle behind the calipers. If it doesn't have traction control then you need to remove the reluctor ring from the open carrier using a rubber mallet and gentle tapping all around it. Then put it on the new diff and use the gears to pressure fit it onto the carreir. Then reinsert the axles, pins, clips and put it all back together. Should be a 2-3 hour job. Depending on skill level.

 

ive rebuilt diffs before and its not too bad maybe a 4 or 5 you need to know some specs for the crush washer tho and the back lash also your going to need an inch lb torque wrench are you going to change the gears??