I've got a 69 12 bolt diff, with stamping EM, and according to the 69 differential page in the parts book equates to a 3.07:1 12 bolt open. While I have a couple 2 series carriers in the garage, I'm now looking for a 3 series carrier. From the research I did some time back the carrier would have casting # EDB 30140 PM1 (I'm not sure about the PM1 part), which would be good for 3.07, 3.31, 3.55 & 3.73 gear sets. I've seen this debated before, but the page shows units with 3.07 gears being 12 bolts, and 3.08 gears being 10 bolts.
GM 12 bolt posi. 68-72 A body. Casting number 3959038 late 1969, series 3 Eaton posi, has 4.11 Strange/US Gear ring and pinion. No brakes. Very good condition. Originally from 1969 Canadian built Oldsmobile 442. With 3.08:1 according to the code stamped into the housing. Chevelle, Skylark, Cutlass, Lemans, Buick GS, 442, GTO
Thanks Carl. Unfortunately I'm working with a B-body, and don't require the whole differential, just the carrier. I don't even require the inner workings, as I have new spider gears & clutch pack, etc.
The posi units and gears are interchangeable but the Impala, Chevelle Nova housings are all different. Even the truck posi units work but the truck pinion bearing is smaller. It's common to use a ring gear spacer to use 3 series gears on a 2 series carrier.
Thanks Randy
-- Edited by GLHS60 on Friday 20th of December 2013 07:11:33 PM
I'm not sure where the confusion is coming from, but an a-body differential housing is different than a b-body differential housing, even though the gear carriers are shared between them. However, an 'open' gear carrier is different than a 'limited slip' or 'posi' housing, and there a 2, 3 & 4 series carriers.
So, what I'm looking for is a bare 12 bolt 3 series posi gear carrier, casting number EDB 30140 PM1. I hope this clears up the confusion.
This is what Clint is looking for, the elusive ED-30140PM1
Old picture of one I did way back. ebay item from Tonawanda NY. Drove over to pick it up. included the housing as well. $400.
Another option is you could always go with a new Eaton unit. Truthfully, if numbers didn't matter I think I'd spend the couple of hundred more up front. Rebuilding these will cost at least $200 with new spiders, bushing washers, springs and clutches.
The new Eaton is said to be far more robust in the clutches.
Somebody's gotta have one of these kicking around somewhere.
If or when you find one, are you going to set it up yourself or have someone do it?
I'll have to get someone to set it up. I've got all the guts for the posi unit, and it should be as simple as putting the guts in the posi carrier, bolting the ring gear onto the posi carrier, putting the posi carrier in the housing and checking the backlash. Probably simple for someone who knows what they're doing, but way out of my league.
I've got a 69 12 bolt diff, with stamping EM, and according to the 69 differential page in the parts book equates to a 3.07:1 12 bolt open. While I have a couple 2 series carriers in the garage, I'm now looking for a 3 series carrier. From the research I did some time back the carrier would have casting # EDB 30140 PM1 (I'm not sure about the PM1 part), which would be good for 3.07, 3.31, 3.55 & 3.73 gear sets. I've seen this debated before, but the page shows units with 3.07 gears being 12 bolts, and 3.08 gears being 10 bolts.
Sorry Clint, I thought I might have but all I could find was 2 bare 3 series carriers for non-posi.
__________________
1966 Strato Chief 2 door, 427 4 speed, 45,000 original miles
1966 Grande Parisienne, 396 1 of 23 factory air cars
I've got a 69 12 bolt diff, with stamping EM, and according to the 69 differential page in the parts book equates to a 3.07:1 12 bolt open. While I have a couple 2 series carriers in the garage, I'm now looking for a 3 series carrier. From the research I did some time back the carrier would have casting # EDB 30140 PM1 (I'm not sure about the PM1 part), which would be good for 3.07, 3.31, 3.55 & 3.73 gear sets. I've seen this debated before, but the page shows units with 3.07 gears being 12 bolts, and 3.08 gears being 10 bolts.
IWE Rear Ends Only
