View Full Version : 12 bolt


Z10 Paceman
Mar 14th, 06, 07:14 PM
need to know what spline the axles are in a 12 bolt?

1969 RS/SS DROPTOP
Mar 14th, 06, 07:22 PM
30 spline if thats what you need to know.

fmfire672
Mar 16th, 06, 03:00 PM
does anyone have the casting numbers / part numbers to identify the 12 bolt carrier series?

Larger Dave
Mar 16th, 06, 03:37 PM
The 2 series is ED32088, the 3 series is EDB30140 and the 4 series is EDB30174. EDB 32212, E228 is a 3 series for a 12 bolt truck rear end.


Larger Dave

fmfire672
Mar 16th, 06, 05:28 PM
thanks dave, I have the series 4 , it looks like it has hardened axle gears in it

big gear head
Mar 16th, 06, 08:32 PM
The standard gears for the Eaton posi had 18 teeth on the axle gears and 10 on the pinion gears. The special high performance Eaton had 17 and 10 gears in it. Which ones do you have?

fmfire672
Jan 24th, 08, 08:13 AM
Does anyone know on a 12 bolt posi series 3 if it will take a gm 3:73 gear or not? Thanks Tom

1962vette
Jan 24th, 08, 03:17 PM
The 3 series relates to gears starting with a 3 like; 3.08, 3.31, 3.55, 3.73. So yes, a GM 3.73 gear will be fine as long as it is for a passenger car 12 bolt.