chev 12 bolt

paulbass · 01-26-2011, 12:40 AM

a have a 12 bolt rearend was wondering what it came out of #3894860nf tube #bm 0213g2 A279 con1 can anyone help?

KingReptile · 01-26-2011, 01:56 AM

Quote:

Originally Posted by paulbass

a have a 12 bolt rearend was wondering what it came out of #3894860nf tube #bm 0213g2 A279 con1 can anyone help?

68 Chevy II with 3:31:1

paulbass · 01-26-2011, 12:16 PM

would you know if it was originally a posi unit. and i thought that the last number on the housing was the year?

FED 387 · 01-26-2011, 01:19 PM

BM is a 3:31 OPEN NOT a posi

paulbass · 01-26-2011, 03:35 PM

could someone have changed the case because if i turn one side or the other both sides turn, even when i turn the pinion. inside it looks like on each side there is a plate w/springs. thanks for your help.Paul

FED 387 · 01-26-2011, 03:44 PM

The ORIGINAL rear end that came from GM was a 3:31 open gear---that is not to say that somewhere down the road it has not been changed to either a POSI or an entirely different ratio--- but as originally manufactured it was a 3:31 open ---sounds like ya got a posi in there whats the numbers on the gears???

paulbass · 01-26-2011, 04:04 PM

the ring gear has #3093 419 usa y ? 1x on the case # ed3 30174 another # e 2 10

does those numbers help you any ?

01-26-2011, 12:40 AM	#1
paulbass Junior Member Join Date: Jan 2011 Location: winona Posts: 5 Likes: 0 Liked 0 Times in 0 Posts	chev 12 bolt a have a 12 bolt rearend was wondering what it came out of #3894860nf tube #bm 0213g2 A279 con1 can anyone help?

01-26-2011, 01:19 PM	#4
FED 387 VIP Member Join Date: Jun 2006 Posts: 3,399 Likes: 482 Liked 320 Times in 172 Posts	Re: chev 12 bolt BM is a 3:31 OPEN NOT a posi

01-26-2011, 03:35 PM	#5
paulbass Junior Member Join Date: Jan 2011 Location: winona Posts: 5 Likes: 0 Liked 0 Times in 0 Posts	Re: chev 12 bolt could someone have changed the case because if i turn one side or the other both sides turn, even when i turn the pinion. inside it looks like on each side there is a plate w/springs. thanks for your help.Paul

01-26-2011, 03:44 PM	#6
FED 387 VIP Member Join Date: Jun 2006 Posts: 3,399 Likes: 482 Liked 320 Times in 172 Posts	Re: chev 12 bolt The ORIGINAL rear end that came from GM was a 3:31 open gear---that is not to say that somewhere down the road it has not been changed to either a POSI or an entirely different ratio--- but as originally manufactured it was a 3:31 open ---sounds like ya got a posi in there whats the numbers on the gears???

01-26-2011, 04:04 PM	#7
paulbass Junior Member Join Date: Jan 2011 Location: winona Posts: 5 Likes: 0 Liked 0 Times in 0 Posts	Re: chev 12 bolt the ring gear has #3093 419 usa y ? 1x on the case # ed3 30174 another # e 2 10 does those numbers help you any ? Last edited by paulbass; 01-26-2011 at 09:44 PM.

01-26-2011, 12:16 PM	#3
paulbass Junior Member Join Date: Jan 2011 Location: winona Posts: 5 Likes: 0 Liked 0 Times in 0 Posts	Re: chev 12 bolt would you know if it was originally a posi unit. and i thought that the last number on the housing was the year?