REAR END RATIO AND TYPE ID FOR 85 ELKY

[Neuron]

I got under the ELKY and wire brushed off the crud to see the numbers on the rear end passenger side axle tube and the number was 9AX C085 1.My chevy shop manual for 1985 does not even list the 9AX, and I double checked it again and it is definitely 9AX. Any body know what ratio and posi or not?

 

[pontiacgp]

take the cover off and take a look. The rear end oil is probably overdue for a change anyway

 

[Neuron]

Yea to check for posi that sounds ok but the ratio would involve counting the number of teeth on the ring and pinon gear or is the ratio stamped somewhere on the gear?

 

[pontiacgp]

the numbers are stamped on the crown gear...just divide them to get your ratio. Also beside the gears maybe being replace someone may have upgraded to a 7 5/8 carrier with 28 spline axles. With cars this old that have usually gone thru a few owners you never know what's been changed.

 

[Gator33]

I have a '86 "Choo - Choo SS and it has 273 gears. Don't know if that helps out? I just turned the wheel and counted the rotation of the spool to the rotation of the wheel. If it is a stock 10 bolt 7.5" it will either have 273 or 323 gears. More than likely it isn't a posi either?

 

[azmalibuwagon]

I'm 100% sure on this, but IIRC, 9AX is a 2.73.

 

[pontiacgp]

The car is 27 years old, I would not rely on numbers stamped on a decal or anywhere else. It has ten bolts to remove to verify what the gearing is. If someone does not know what their car's gearing is then that means they have never had the cover off to change the oil. Rear end oil doesn't last forever and it will rob of you of power and gas millage if not maintained properly until it explodes.