rear end question
 

how do i identify my rear end carrier with out totally disasembeling my rear end. i have the cover off but i know there is a 3 and a 4 series carrier and i need to know if there is a simple way to identify them...:confused:

Re: rear end question
 

Here's the number on a series 4 carrier

Re: rear end question
 

well its hard to see the pinion but the ring gear has 41 teeth its an open diff 12 bolt short bed truck that had a 6 cyl orginal

Re: rear end question
 

So? If it's an open carrier then it's not a series 4 posi then. The picture i posted is a series 4 posi carrier.

Re: rear end question
 

Does your glovebox have the tag on it? I found a chart that shows what the RPO codes mean.

Re: rear end question
 

I'm no expert, but just from what I know a 41 tooth ring gear is gonna be either a 3.42, a 3.73, or a 4.56

If you have a tach & it was drivable, I have a chart that can tell you what you have if you know your RPM's at 60 MPH & you need your tire height in inch's

Re: rear end question
 

yea mine says 3866116n, i new it was not a posi i just did not know if it could be replaced with eather 3 or 4 series if i have to change all the guts or what. all i know is that i want to have a posi 3.73 witch will require a 3 series but i would settel for a 4.10 with a 4 series if it would fit. if you know much about this tell me what i need to do to get what im after...

Re: rear end question
 

3.73 is the dividing point, series 3 goes up to 3.73, & series 4 starts from 3.73, so that may help you decide which carrier, all I know is I wouldn't take on the task of exchanging rear end gear carriers unless I really knew what i was up against, there's the shims, the backlash, making sure the teeth run in the center . I've been told it would be alot easier to find another rearend that had Posi in it, & swap the whole thing out, yours being a 67, there is the dillema of will a 70 & 1/2 to 72 rearend fit? They are a little wider, but some guys on here have done it & are still driving it, I think there is something about using later model truck calipers maybe?

Re: rear end question
 

I only know all this stuff cause I've been searching for an Eaton series 4 posi for about 6 months now, so I can tell the difference between a series 3 & a 4

here's a used sereis 4 for sale on evilbay

http://cgi.ebay.com/ebaymotors/12-BO...ayphotohosting

Re: rear end question
 

Ring Gear Teeth/Pinion Gear Teeth = Rear End Ratio (if that'll help you any).

Mine was a 3.07 (43 ring gear teeth and 14 pinion gear teeth I think)

43/14=3.07

DLB

Re: rear end question
 

Yep, & a 41 with an 11 is a 3.73 gear