Rear End Gears

[JRF57]

I need some info from any of you guys that can help. I just had a complete differential/axle rear end replacement due to the original rear end falling apart at 70k miles with a like kind and quality from a used car (aftermarket warranty rules). BEFORE the swap I had a 3.23 rear end coupled with an auto tranny. After the replacement Im not sure what I got. I am now showing 10 miles per hour LESS on the speedometer when someone is clocking me. When Im showing 50mph they are showing 60. When I show 60 they are at 70. Does this mean the rear gear they swapped is higher (2.73) or lower (3.42)? Im thinking it is higher because it doesnt seem to have the snap it once had. If they didnt put back what I had what recourse do I have besides flattening the place?

Any info is appreciated before I go down there Monday and have a heart to heart with the shop-----

[Slopoke]

Jack the car up so that both rear wheels can turn freely. Put a chalk mark or use whatever to mark the right tire and the drive shaft. Put the car in nuetral. Turn the drive shaft by hand counting the revolutions it takes for the tire to make one complete revolution back to the original starting point. This will give you a ball park gera ratio. If you turn th edrive shaft less than 3 revolutions for the tire to reach its starting point the ratio osprobably the 2:73.

[Hot Black Trans-Am]

Someone got a screwin!!! I'd def go and do some ass kicking! They should tell you if it's not the same specs.

[mbrownin]

Yep, sounds like you got 2.73's now. Computer is calibrated for 3.23's. If you swap in 2.73's w/o updating the computer, 50 indicated will be an actual 59.2. 60 indicated will be an actual 71 mph.

[JRF57]

Thanks guys for confirming my suspicion.....If I make it through the weekend without having a redass stroke Im gonna be at the door Monday morning

[JRF57]

Since I will have to prove what I had in the car can anyone tell me what code the camaro used for the 3.23 ratiod rear end? I still have the sticker on the door with all the codes but dont know which ones prove it. Also is there a way I can get a print out of the options from the factory? Do they keep that kinda stuff for 5 years?

[keliente]

GU5 = 3.23s. You can find the sticker on the door jamb or in the glovebox. Any GM dealership can print out your vehicle's options.

[JRF57]

Thanks for the info K. GU5 is what it shows.