12 bolt differential info needed - The 1947 - Present Chevrolet & GMC Truck Message Board Network

HackJob65 · 03-06-2016, 10:30 PM

So I am rebuilding the rearend for my 65 which has the 64 style panhard bar and 17 spline axles.I had a 12bolt gov loc laying around and decided to use it and save some money. I bought new 30 spline axles and a 3.73 thick gear set to go on the carrier that had the ring from a 2.76 ratio on it. Being that the carrier was a gov loc I assumed it was a 12 bolt truck 3 series unit. Until I had bearings and gear mounted and dropped it into housing. The ring gear bolts hit part of the housing and even with all shims on one side backlash can be measured with a tape measure. So I removed from housing and set it next to the original. After some internet research I found dimensions for car and truck 12 bolt carriers according to the series. I have determined that this is a car series 2 carrier. Has anybody ever seen a gov loc in a car or did they ever build vans or trucks with a car housing?

**PGSigns** · 03-07-2016, 01:29 PM

The made a few versions of that thing and it could be from a 10 bolt.
Jimmy

HackJob65 · 03-07-2016, 05:35 PM

After searching the web I decided to call a know it all of differentials. The guys at Randy's Ring and Pinion had an answer. Although rare and there is no aftermarket support for it apparently there is a GM 12 bolt Truck series 2 carrier. The only ratio was a 2.73.

03-06-2016, 10:30 PM	#1
HackJob65 Registered User Join Date: Apr 2015 Location: MO Posts: 42	12 bolt differential info needed So I am rebuilding the rearend for my 65 which has the 64 style panhard bar and 17 spline axles.I had a 12bolt gov loc laying around and decided to use it and save some money. I bought new 30 spline axles and a 3.73 thick gear set to go on the carrier that had the ring from a 2.76 ratio on it. Being that the carrier was a gov loc I assumed it was a 12 bolt truck 3 series unit. Until I had bearings and gear mounted and dropped it into housing. The ring gear bolts hit part of the housing and even with all shims on one side backlash can be measured with a tape measure. So I removed from housing and set it next to the original. After some internet research I found dimensions for car and truck 12 bolt carriers according to the series. I have determined that this is a car series 2 carrier. Has anybody ever seen a gov loc in a car or did they ever build vans or trucks with a car housing? Attached Images

03-07-2016, 01:29 PM	#2
PGSigns Senior Member Join Date: Jan 2011 Location: Hayes Va Posts: 4,569	Re: 12 bolt differential info needed The made a few versions of that thing and it could be from a 10 bolt. Jimmy __________________ 60 to 66 Chevy and GMC window decals http://67-72chevytrucks.com/vboard/s...d.php?t=661131 Good friends, good food and a hotrod what else do you need? 1966 BBW long fleet Daily driver 1965 BBW short fleet Sold and going to a good home 1965 Suburban 2003 3500 Duramax 2005 Ultra Classic

03-07-2016, 05:35 PM	#3
HackJob65 Registered User Join Date: Apr 2015 Location: MO Posts: 42	Re: 12 bolt differential info needed After searching the web I decided to call a know it all of differentials. The guys at Randy's Ring and Pinion had an answer. Although rare and there is no aftermarket support for it apparently there is a GM 12 bolt Truck series 2 carrier. The only ratio was a 2.73.



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