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#65415 09/08/2006 5:06 AM | Joined: Jun 2006 Posts: 74 Wrench Fetcher | | Wrench Fetcher Joined: Jun 2006 Posts: 74 | I have a 56 TF w/ 350 engine and T400 tranny. The differential is a chevy 12 bolt, but I don't see any defining numbers other than (GM 58) and (3896839N). I'm trying to determine make, model and year of the vehicle that the rear end might have come from.
I've also search around the board here to decipher the number sequence, but it hasn't jump out at me. I have found information about popping the cover off and count teeth to get ratio. So I have that going for me.
Does anyone have any other suggestions that I can try to get a better feel for what I might have so I can figure out my next steps? | | |
#65416 09/08/2006 10:04 PM | Joined: Jun 2004 Posts: 8,597 Riding in the Passing Lane | | Riding in the Passing Lane Joined: Jun 2004 Posts: 8,597 | If you pop the cover, on the edge of the ring gear the ratio & date will be stamped on it. The ratio is like 10-41. It means 10 teeth on the pinion & 41 on the ring gear. 4:11 ratio.
They say money can't buy happiness. It can buy old Chevy trucks though. Same thing. 1972 Chevy c10 Cheyenne SuperIn the Gallery Forum | | |
#65417 09/08/2006 10:06 PM | Joined: Jun 2004 Posts: 8,597 Riding in the Passing Lane | | Riding in the Passing Lane Joined: Jun 2004 Posts: 8,597 | If you pop the cover, on the edge of the ring gear the ratio & date will be stamped on it. The ratio is like 10-41. It means 10 teeth on the pinion & 41 on the ring gear. 4:11 ratio.
They say money can't buy happiness. It can buy old Chevy trucks though. Same thing. 1972 Chevy c10 Cheyenne SuperIn the Gallery Forum | | |
#65418 09/09/2006 12:21 AM | Joined: Jun 2005 Posts: 887 Shop Shark | | Shop Shark Joined: Jun 2005 Posts: 887 | How about trying it a different way? Do a title search with carfax and call the PO's to ask them what the donor car/truck was.
If that doesn't work and all else fails, since you are probably curious because you need replacement parts, just pull the offending seal/brakeshoe, spring, etc... and take it to NAPA- they can cross the parts using the numbers stamped on them and might also be able to figure out the donor using the same info.
12 bolts weren't used for too long. There are some 'faux 12 bolts' which have 12 bolt covers but 10bolt ring and pinion gears inside them.
12 bolts came in cars and trucks and there is a slight difference between the two types.
There are also three types of 12 bolt posi's- two with carrier's that have clutches and one that is straight gear driven, if I'm not mistaken.
Good luck!
'51 Chevy 1/2 ton w/'62 261, HEI, offy, fentons, dual carter/webbers, t-5 & 12 bolt posi
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#65419 09/14/2006 2:40 AM | Joined: Jun 2006 Posts: 74 Wrench Fetcher | | Wrench Fetcher Joined: Jun 2006 Posts: 74 | NM51
Thanks for the advice. I was planning on pulling the cover off to determine the ratio, but I didn't think to try and track down the type through NAPA.
Thanks again. | | |
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