I am new to the Corvette Forum. My brother has been a member for some time. I have an 86 corvette and he has a 70 Vett. I was wondering how to I find out what my Gear Rotio is in the rear end. I think he said he has 3.09 and my Vett is so much faster than his. Anyone got a clue?
Re: Gear Ratio for 86 corvette coupe (8686corvette)
I think the ratio is 3.07 gears. I know mine is and I also have a '86 coupe. There is a way you can get some what close. Jack up or lift the car so the rear wheels are off the ground. Put the car in neutral and turn the rear wheel and count the number of times the drive shaft turns to make one complete rotation of the rear wheel. A guy I work with told me about this trick. It would probably be a good idea to mark the drive shaft first. If the rear is stock, I think it is 3.07.
Re: Gear Ratio for 86 corvette coupe (jimswhite92)
If you know the gears are original you can tell from the RPO codes located in the panel behind the passenger seat.G44 - Rear axle 3.07 ratio
G87 - Ring gear 8.50 inch
G92 - Rear axle performance ratio
GH0 - Rear axle 3.54 ratio
GM1 - Rear axle 2.59 ratio
GM3 - Rear axle 3.45 ratio
GT7 - Rear axle 3.33 ratio
GU2 - Rear axle 2.73 ratio
GW4 - Rear axle 3.31 ratio
i looked on the back of my seat and couldnt find them were else might i look
You've found yourself a 126 month old thread that started out as an axle ratio request. What are you looking for? You don't mention the year of your car. What year is it?
If you're looking for the SPID label, or RPO option label (call it what you like) it's location varies by year. None were on the back of the seat.
If it's an '84 or '85 it's on the storage compartment frame behind the driver. Not on the lid but stuck to the floor portion of the compartment frame.
'86 and later it would be on the back-side of the center console door.
If you don't find it in those two locations you won't find it. What sort of information are you looking for? You can purchase a build sheet by VIN from the NCM that would supply all of the information you're likely looking for.