View Full Version : Posi??

02-24-2010, 09:26 AM
After a wheel test andwith the diff cover off, what does a 14 bolt look like if its posi? Also a 12 bolt rear? The 14 bolt is hard to see into. Any factory id on tubes etc., if tags gone? A guy wants a posi rear 1/2 ton diff which I may have but don't want to sell him an open diff:p Can you post some pics?

02-24-2010, 04:55 PM
You don't want a posi 1/2 ton diff will go boom 14 bolt isn't a 1/2 ton diff so

http://i64.photobucket.com/albums/h200/Geardrivensteam/POSI.jpg should look something like this

perhaps u post pics of the diffs in question?

02-25-2010, 01:09 AM
[38] thats why they call them tick tock boom

02-25-2010, 12:03 PM
I took the cover off my 12 bolt 1/2 ton diff and its posi:party0010: Looks just like this pic except my diff case is different;) It turns out it has 43 crown teeth and 13 pinion teeth, 3:08 gears. Is not the gear ratio for highway use??


My 14 bolt under my Jimmy looks like this pic but unfortunately my case is not shaved:( Even though I put a detroit locker in mine its hard to tell its in there. Unlike a 12 bolt posi how could you see if your 14 bolt was posi? I guess for a 14 bolt only way is to take it apart.


02-25-2010, 12:31 PM
I pulled the cover off 2 other 1/2 tons with 12 bolt diffs and both look open to me.

47 teeth on crown, 17 teeth on pinion, 2.7647 gear rato, this 81 4x4 pick-up has an sm465 and 235/75/R15 tires. Belongs to my freind Bill who complains about it being too slow so he is thinking of going bigger tires and try to find a 700R4.

40 teeth on crown, 13 on pinion, 3.0769 gear ratio. I guess that 3.08? This diff is under a 1980 pick-up 4x4.

And the Blazer with the rear posi, 43 teeth on crown, 14 on pinion, 3.0714 gear ratio (3.07??)

02-25-2010, 06:30 PM
Damn I got 3.42s in my truck and I want to go higher I don't think i could handle 2.76s with 33s..... The neighbor had an old work truck with 2.76 was a 1/2 ton 81 4 speed 208 wouldn't even think about wheeling that way to low I think 3.42 is a decent choice for stock highway/offroad but I find with 33s my truck still has to much highway

02-28-2010, 08:15 AM
Heres a pic of the 3:42's, Theres a burr on the bottom of the grooves between the teeth. I wonder what that is??


How do you tell if there is a locker in there, unlike a 12 bolt diff where you can see in the carrier??


How do you tell if there is a locker in there, unlike a 12 bolt diff where you can see in the carrier??

02-28-2010, 08:46 AM
If the carrier has 4 holes looking in at the spider gears then its open if its only got three then its a gov lock according to one site which is y u need an open carrier to put a detriot in

03-01-2010, 06:49 AM
You cant put a detoit locker in a gov lock carier because you need 4 holes. I get it.