How to tell whether u have a 12 or 10 bolt rear end? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

*Robo_bot* · 02-22-2004, 03:21 PM

i have a six lug rear end in my truck 1969 GMC 1/2 ton and i was wondering how do i know whether it is a 12 bolt or 10 bolt? cause im also looking for a 3.73 posi for it??

bad 71 chevy · 02-22-2004, 03:30 PM

count the number of bolts on the rear cover

*Robo_bot* · 02-22-2004, 03:33 PM

k cool thanx i counted its a 10bolt but can i still get a 3.73 posi for it do u guys think?

*rage'nrat638* · 02-22-2004, 03:42 PM

y yes you can

*Robo_bot* · 02-22-2004, 03:43 PM

k cool thanx

1969 GMC · 02-22-2004, 04:30 PM

do you have any pics of your rear diff? the reason I ask is, GM didn't put corporate 10 bolt axles in 67-72 trucks. the majority of 1/2 tons used 12 bolts. but GMC had to do things a little differently, and some of the early trucks had dana 44 & dana 60 semifloating rear axles, both with 6 lugs, for rearends. actually, if it has a fill plug on the diff cover, its a dana axle. if not, someone swapped in a corporate 10 bolt.

*Robo_bot* · 02-22-2004, 04:44 PM

ya heres a pic of it

*rage'nrat638* · 02-22-2004, 04:55 PM

looks like a 12 bolt to me

lukecp · 02-22-2004, 04:55 PM

That would be a 12-bolt. Like Adam said, 10-bolts weren't used in these trucks. They came out in the late 70's i think.

FirstGen · 02-22-2004, 05:26 PM

really? I'm pretty sure I counted my '68 Chevy and it had a 10 bolt, maybe I'm wrong???

Anyway, so if it is a 12 bolt is it the same as the muscle car carrier 8.875" or do you have to get a special truck carrier?

Thanks

Longhorn Man · 02-22-2004, 05:30 PM

Not the same as a car unit.

lukecp · 02-22-2004, 05:31 PM

Here is a guide:

http://www.coloradok5.com/axleguide.shtml

FirstGen, someone may have swapped one in, but is should be a 12-bolt.

*Robo_bot* · 02-22-2004, 06:06 PM

k cool thanx guys

FRENCHBLUE72 · 02-22-2004, 06:28 PM

Here's a good pic of the 12 bolt in my 72 a 10 bolt is more round and has of coure 10 bolt's holding the diff cover on..

*Robo_bot* · 02-23-2004, 10:34 PM

thanx guys that helps me alot

1969 GMC · 02-24-2004, 01:17 AM

Quote:

Originally posted by FirstGen
really? I'm pretty sure I counted my '68 Chevy and it had a 10 bolt, maybe I'm wrong???

I should clarify what I said in my above post. Your axle may have 10 bolts holding the diff cover on, and it could be original. The dana 44 and dana 60 rear axles both had 10 bolts. best way to check is if the fill plug is on the diff cover or on the side of the pumpkin. these axles, while fairly uncommon in early run trucks, did pop up once in a while.

FirstGen · 02-24-2004, 01:59 AM

so where are you saying the fill plug should be if it is a Dana rear? I think it was on the pumpkin.

02-22-2004, 03:21 PM	#1
Robo_bot Account Suspended Join Date: Feb 2004 Location: Kelowna BC Canada Posts: 481	How to tell whether u have a 12 or 10 bolt rear end? i have a six lug rear end in my truck 1969 GMC 1/2 ton and i was wondering how do i know whether it is a 12 bolt or 10 bolt? cause im also looking for a 3.73 posi for it??

02-22-2004, 03:30 PM	#2
bad 71 chevy Registered User Join Date: Jun 2000 Location: Omaha NE 68122 Posts: 637	count the number of bolts on the rear cover __________________ 71 Chevy C/10 lwb 350 5 speed nv3500 3.73 rear end 2.5" Front Drop and 4" in the back Edelbrock perfomer rpm manifold Edelbrock 600 cfm carb Headmen headers

02-22-2004, 04:30 PM	#6
1969 GMC Registered User Join Date: Feb 2003 Location: The Rubber City Posts: 5,498	do you have any pics of your rear diff? the reason I ask is, GM didn't put corporate 10 bolt axles in 67-72 trucks. the majority of 1/2 tons used 12 bolts. but GMC had to do things a little differently, and some of the early trucks had dana 44 & dana 60 semifloating rear axles, both with 6 lugs, for rearends. actually, if it has a fill plug on the diff cover, its a dana axle. if not, someone swapped in a corporate 10 bolt. __________________ 1969 GMC K2500 1996 Honda Accord 2007 Kawasaki KLR 650

02-22-2004, 04:44 PM	#7
Robo_bot Account Suspended Join Date: Feb 2004 Location: Kelowna BC Canada Posts: 481	ya heres a pic of it Attached Images

02-22-2004, 04:55 PM	#9
lukecp Formerly yellow72custom Join Date: May 2001 Location: Austin, TX Posts: 7,531	That would be a 12-bolt. Like Adam said, 10-bolts weren't used in these trucks. They came out in the late 70's i think. __________________ '72 Chevy C10 Mild 350/TH350/3.07. Ochre/White. Old high school ride. '70 GMC C2500 '62 327 4bbl/SM465/4.56-geared Dana 60. White/White. Project or parts truck. '97 Saturn SL DD. 1.9/5-speed. 40+ highway mpg

02-22-2004, 03:33 PM	#3
Robo_bot Account Suspended Join Date: Feb 2004 Location: Kelowna BC Canada Posts: 481	k cool thanx i counted its a 10bolt but can i still get a 3.73 posi for it do u guys think?

02-22-2004, 03:42 PM	#4
rage'nrat638 Account Suspended Join Date: Mar 2003 Location: THE FALL GUY CHICAGO IL Posts: 5,883	y yes you can

02-22-2004, 03:43 PM	#5
Robo_bot Account Suspended Join Date: Feb 2004 Location: Kelowna BC Canada Posts: 481	k cool thanx

02-22-2004, 05:26 PM	#10
FirstGen Just Don't Stop! Join Date: Feb 2004 Location: Dallas Posts: 1,239	really? I'm pretty sure I counted my '68 Chevy and it had a 10 bolt, maybe I'm wrong??? Anyway, so if it is a 12 bolt is it the same as the muscle car carrier 8.875" or do you have to get a special truck carrier? Thanks __________________ 1968 C10 build in process TT LSA/6L90e/9"

02-22-2004, 05:30 PM	#11
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Not the same as a car unit.

02-22-2004, 05:31 PM	#12
lukecp Formerly yellow72custom Join Date: May 2001 Location: Austin, TX Posts: 7,531	Here is a guide: http://www.coloradok5.com/axleguide.shtml FirstGen, someone may have swapped one in, but is should be a 12-bolt. __________________ '72 Chevy C10 Mild 350/TH350/3.07. Ochre/White. Old high school ride. '70 GMC C2500 '62 327 4bbl/SM465/4.56-geared Dana 60. White/White. Project or parts truck. '97 Saturn SL DD. 1.9/5-speed. 40+ highway mpg

02-22-2004, 06:06 PM	#13
Robo_bot Account Suspended Join Date: Feb 2004 Location: Kelowna BC Canada Posts: 481	k cool thanx guys

02-22-2004, 06:28 PM	#14
FRENCHBLUE72 PROJECT 7DEUCE Join Date: Dec 2002 Location: GRANTS PASS OR Posts: 21,606	Here's a good pic of the 12 bolt in my 72 a 10 bolt is more round and has of coure 10 bolt's holding the diff cover on.. Attached Images __________________ GO BIG GREEN GO DUCKS MEMBER #6377 72 k-5 daily driver 6'' lift 35'' 350-350-205 slowly getting rust free. Project "7DEUCE" check out my build http://67-72chevytrucks.com/vboard/s...d.php?t=267665 Tim Powell..R.I.P EastSideLowlife..... R.I.P..

02-23-2004, 10:34 PM	#15
Robo_bot Account Suspended Join Date: Feb 2004 Location: Kelowna BC Canada Posts: 481	thanx guys that helps me alot

02-24-2004, 01:59 AM	#17
FirstGen Just Don't Stop! Join Date: Feb 2004 Location: Dallas Posts: 1,239	so where are you saying the fill plug should be if it is a Dana rear? I think it was on the pumpkin. __________________ 1968 C10 build in process TT LSA/6L90e/9"



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