Anyone here know a quick way to determine gear ratios? my buddy looked at my codes in the glove box and from what he could make of them, he thinks the car had 3.48 or 3.42 gears, but, the speedo is VERY noticably off... and the car frickin HAULS!!!! WAAAAY more than it should.... i get maybe 20mph out of 1st gear, at full throttle... but that 1st to 2nd transition is killer.... i feel like im in a new vette.... im thinking the guy before me may have slapped some 3.73s in it. the car came with everything you see in my sig ling except for the cowl induction hood. so who knows, maybe that 3.73 is an option. anyone know a quick way to tell?

 

Get the rearend off the ground and support the car. Put the car in neutral and spin the rear tires by hand. Count the # of revolutions the driveshaft makes in the time it takes you to turn the tire one full revolution. A friend who can count would be handy for this as well.

 

then what? ive heard of that before, but never in detail of how it works... so lets say it turns 2 and 3/4 turns.... whats that mean? (no it didnt turn that im just trying to figure out how this will help me lol)

 

Basically it would mean you're sporting a 2.73:1 axle ratio.
If it turns 3 turns, it's probably a 3.08.
3 1/4 turns is probably a 3.23/3.27.
3 1/2 turns is a 3.42.
3 3/4 turns is a 3.73.
4 turns would be a 4.10.

 

see.... that is WONDERFUL advice, im going to try this tomarrow, im DYING to know whats in there! i know today i found out my speedo is 2/10 of a mile off..... which means i must have something pretty serious in there. im going to check it out tomarrow. thanks a million!

 

Best foolproof way to check gear ratio is take off the rear end cover, then count the teeth on the ring and on the pinion. Divide the ring teeth by the pinion teeth and this is the exact gear ratio.