Question about differential options - The 1947 - Present Chevrolet & GMC Truck Message Board Network

crawdad · 08-29-2006, 09:34 PM

One of the options on the option sheet for my truck is code "G80 - Locking Differential". Exactly what kind of locking differentials did GM put in the trucks? Is it a straight positive traction or is it some type of limited slip? Just curious. I just picked this truck up. It has 2.73 gears in it with supposedly a locking differential, and a 700R4 tranny. I would have thought that with the 700R4 it would have had a lower geared differential. I got great gas miledge coming home with it. I wonder why?

crawdad · 08-30-2006, 09:13 AM

Well after doing some more searching it would appear that a limited slip and a positraction unit are both the same. It also looks like GM calls theirs a positraction unit when it is actually a limited slip. Does this sound correct?

Prerunner1982 · 08-30-2006, 09:26 AM

I know in the military trucks the stock locking diff is called a Gov Lock, I believe it to be the same in civilian trucks as well. Havent heard anything really good about them, but I am sure they work just fine under normal use.

**Captkaos** · 08-30-2006, 05:22 PM

G80 is GM's designation for a limited Slip differential. They Name they gave it was Positraction. Prior to about 1980 they used Eaton clutch diffs afterwards they went to Eaton Gov-Locs. Either will server you well in normal situations.

crawdad · 08-30-2006, 07:29 PM

Thanks, appreciate it.

mntoy · 09-03-2006, 10:41 PM

How did you determine that your G80 rearend had 2.73 gears?

crawdad · 09-04-2006, 01:07 AM

It was stated on the RPO list in the glove box.

08-29-2006, 09:34 PM	#1
crawdad Senior Member Join Date: Sep 2004 Location: Georgia Posts: 614	Question about differential options One of the options on the option sheet for my truck is code "G80 - Locking Differential". Exactly what kind of locking differentials did GM put in the trucks? Is it a straight positive traction or is it some type of limited slip? Just curious. I just picked this truck up. It has 2.73 gears in it with supposedly a locking differential, and a 700R4 tranny. I would have thought that with the 700R4 it would have had a lower geared differential. I got great gas miledge coming home with it. I wonder why? __________________ 2012 Silverado LT 1500, 5.3, 6 speed auto '86 SWB C-10 Silverado

08-30-2006, 09:13 AM	#2
crawdad Senior Member Join Date: Sep 2004 Location: Georgia Posts: 614	Re: Question about differential options Well after doing some more searching it would appear that a limited slip and a positraction unit are both the same. It also looks like GM calls theirs a positraction unit when it is actually a limited slip. Does this sound correct? __________________ 2012 Silverado LT 1500, 5.3, 6 speed auto '86 SWB C-10 Silverado

08-30-2006, 09:26 AM	#3
Prerunner1982 Registered User Join Date: Oct 2002 Location: Edmond, OK Posts: 5,904	Re: Question about differential options I know in the military trucks the stock locking diff is called a Gov Lock, I believe it to be the same in civilian trucks as well. Havent heard anything really good about them, but I am sure they work just fine under normal use. __________________ Jon 1982 Chevy Silverado 350/th350.... RETIRED 1993 Jeep XJ 2 door(Cherokee) 4wd 4.0ltr/AX-15 (5spd)/NP231 .... Oklahoma Roll Call

08-30-2006, 05:22 PM	#4
Captkaos www.73-87chevytrucks.com Join Date: Dec 1999 Location: Birmingham, AL Posts: 6,935	Re: Question about differential options G80 is GM's designation for a limited Slip differential. They Name they gave it was Positraction. Prior to about 1980 they used Eaton clutch diffs afterwards they went to Eaton Gov-Locs. Either will server you well in normal situations. __________________ Chris Lucas 1973 Chevy C-10 1978 GMC Jimmy (2WD) - SOLD 1987 R10 twin turbo LS 1991 R3500 SRW CrewCab 1985 K5 diesel swapped project 1989 K5 2WD conversion w/ Vette susp Project Captkaos Customs 73-87chevytrucks.com

08-30-2006, 07:29 PM	#5
crawdad Senior Member Join Date: Sep 2004 Location: Georgia Posts: 614	Re: Question about differential options Thanks, appreciate it. __________________ 2012 Silverado LT 1500, 5.3, 6 speed auto '86 SWB C-10 Silverado

09-03-2006, 10:41 PM	#6
mntoy Registered User Join Date: May 2006 Location: Calif Posts: 43	Re: Question about differential options How did you determine that your G80 rearend had 2.73 gears?

09-04-2006, 01:07 AM	#7
crawdad Senior Member Join Date: Sep 2004 Location: Georgia Posts: 614	Re: Question about differential options It was stated on the RPO list in the glove box. __________________ 2012 Silverado LT 1500, 5.3, 6 speed auto '86 SWB C-10 Silverado



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