[pron70]

i have researched and i cannot find out what gears are in mine without taking off the cover. it has.. FC O 267 on the rear axle tube. its in a 76 nova

[SHIFTY4]

well, an oil/gear lube change & gasket is probably less than 12-15 bucks. probably couldn't hurt


look here: http://www.novaresource.org/axle.htm

[pron70]

i tried that site and its not on there... which is why im having problems.. the layout of the numbers is the same.. but the 0 is for oldsmobile? but cant find the FC ratio

[Philip]

FC is a 7.5" ring gear with a 2.73 ratio.

EDIT....this is for a Chevy from the parts book. If your rear is from an Olds and is an 8.5" it would be rare. Most Oldsmobile Omega's had the 7.5" rear regardless of engine size. Best thing to do is what John suggested..pull the cover and take a look. The gear tooth count is stamped into the edge of the ring gear along with the part number and date.



This one is part #3790629, 12 teeth on the pinion, 37 on the ring, (3.08 ratio), made by GM in November of 63 on 2nd shift.

[monzaz]

I would have to say they probably went off the NOVA codes some what like PC for the 1975-1979 nova is 3.08 P being used for the chevy nova and maybe F being used for the olds with the secound letter being the actual ratio...

The normal ratio would be 2.73 on most cars.

If you have a V8 you would get a higher ratio like 2.73 or 2.56

If you have a 6 cylinder you will normally get a 3.08 gear because the car will need more steep gear for the lack of engine toque. Ok?

Looks like the rear cover may have to come off.

Fluid change is always a good idea anyway.

On the edge of the ring gear the tooth count for the ring and the pinion along with the ring gear part number and date code will be found. divide the small pinion tooth count into the larger ring gear tooth count and you will have your ratio.

13 -40 = 3.08
15 - 41 = 2.73

and so on.

Jim
J D Race.com