HOW WOULD I FIND OUT THE GEAR RATIO FOR THE REAR END OF MY 98 Z28.AS FAR AS I KNOW IT IS STOCK.I CHANGED MY MY TIRE SIZE AND MY POWER PROGRAMMER WANTS TO KNOW GEAR RATIOS?

 

AUTOMATIC TRANSMISSION OR MANUAL TRANSMISSION?

 

automatic

 

In that case, if you know its stock, then it will either be 2.73 gears, or 3.23 gears. other than that i dont know much, sorry. but you will most likely have one of those two gears.

 

THANKS, I WAS WAY OFF.

 

Hey,Specforce how about 99 w/M6?

 

Here's the breakdown guys:

• 2.73's: come standard with the A4 (code GU2)
• 3.23's: are an option for A4's (code GU5)
• 3.42's: are standard and non-optional for the M6 (code GU6)

If you look on the door sticker at the list of codes, you should find either GU2 or GU5 if your car's an auto, or GU6 if it's a standard. This tells you what gears the car has (as long as they're still stock).

HTH.

 

99 M6 w/3.42 yes,but could you please tell me if it has Posi or LSD?
Thankx,T.

 

A posi (short for "Posi-trac") is a form of a Limited Slip Differential (LSD). The LSD in the 4th gens is a Torsen (I think?! ) which is like a posi, but it's not a true "posi". They all work under the same principle though --- one wheel can be held, or turn slower than the other (ie: while cornering) but otherwise the power wants to hit both wheels equally. I think there are actually 2 (or 3??) styles of limited slip's for the 4th gens, but I don't know all the specs on them.