[JBurnz400]

anyone know what the gear ratio is on a 77 Firebird Formula. I dont know if maybe the formula's all had the same rear or not. I've tried spinning both sides simultaniously and the yoke spins bout exactly 3 times. also, I thought when you spin one wheel, the other side i suppose to go the other direction? In my case the other wheel does not move at all. Would this identify if its Limited slip or not?? Thanks for you help

[JBurnz400]

anyone know what the gear ratio is on a 77 Firebird Formula. I dont know if maybe the formula's all had the same rear or not. I've tried spinning both sides simultaniously and the yoke spins bout exactly 3 times. also, I thought when you spin one wheel, the other side i suppose to go the other direction? In my case the other wheel does not move at all. Would this identify if its Limited slip or not?? Thanks for you help

[INJUNBOY]

A 3 letter code was stamped on the front of the passenger's side axle tube to the left of the carrier case to indicate axle ratio and type.If your rearend is the original one that came on your car,here are the codes for the 77 Firebirds,Formulas,and Trans Ams................
2.41 gear ratio was PJG if it is standard rearend and PSG if it was a safe-t-track........
2.56 gear ratio was PHG if it is a standard rearend and PTG if it was a safe-t-track........
3.08 gear ratio was PCG if it is a standard rearend and PWG if it was a safe-t-track........
3.23 gear ratio was PDG if it is a standard rearend and PXG if it was a safe-t-track........
NOTE:The standard rearend does not mean it was a manual standard shift car,it denotes a non- posi rearend.Time to dig out your safety glasses and wire brush !INJUNBOY

[RAJNWDY]

it sounds like you don't have a Saf-t-track rear. jack up one side and count one revolution of the wheel. with that rotation the drive shaft will turn half of the total revolutions. Say you have a 4.11 gear, the drive shaft will spin roughly a smidge over 2 turns. 2.41 will be close to 1.2. I divide the drive shaft in 4 quarters and treat it like a clock. quarter hour, half hour, ect. in any rate you will be close to what the ratio is.

On a Saf-T-Track, you jack up both wheels and spin it. One Rev of the tire and the drive shaft should turn the full revolutions. 3.73 would turn 3 and 3/4's the way around. Good luck

The codes are good too but you have to look for them on the axle tubes. Sometimes that harder because they don't stamp it deep enough or you have to clean the axle from the grime.