question about rear ends - The 1947 - Present Chevrolet & GMC Truck Message Board Network

dropdprpls10 · 02-01-2005, 12:48 PM

a friend of mine has a 12 bolt chevy rear under his 67 chevy long bed.. it was a stock 6 lug pattern he went to the junk yard to get 5 lug axles .. he got them out of a 72.. when he went to put them in he says that they are an inch longer then his stock ones? is this a true statement or does he have something wrong.. i am asking because i have a 10 bolt on my 67 gmc and i want to put a 12 bolt in but dont want a wider one??

junkyardjohn · 02-01-2005, 01:05 PM

YEP.. HE'S RIGHT. AXELS FROM A 67-70 ARE NOT INTERCHANGABLE WITH 71-72 AXELS. JOHN

dropdprpls10 · 02-01-2005, 02:13 PM

so i have to find a 67-70 12 bolt rear end then... thank you very much!!!

junkyardjohn · 02-01-2005, 02:21 PM

71 OR 72 REAR ENDS WILL FIT 67-70s. (THE WHOLE REAR END, NOT JUST THE AXELS)THE 1" PER SIDE IS NO BIG DEAL (EASILY MADE UP WITH BACKSPACING). THE 5 LUG HUBS MORE THAN MAKE UP FOR THE INCONVENIANCE.

JOHN

Longhorn Man · 02-01-2005, 09:23 PM

Interesting that you have a 10 bolt....you might want to measure the width...these trucks never came with 10 bolt rears, so there is no telling what you have under there.
The difference between the early verses late is more liek 3/8 inch per side...not one inch.

68C15 · 02-01-2005, 11:31 PM

I will avoid any potentially embarrasing coments about rear ends. but I will say this, I think the difference can be made up for with different drums. get some measurements & head down to your FRIENDY (patient & knowledgable) parts store. in the book there is listings for part #'s based on these measurements.

Longhorn Man · 02-01-2005, 11:45 PM

You can do that by using the 73 & later drums...HOWEVER...
I said this on another forum, and some one pointed out that the bearings would be riding on a section NOT made for bearings, and that could be an issue. He also pointed out that since the bearings would be in further than designed, there would be more leverage on the axle shafts.

After that being pointed out to me...I say don't try it.

Vince M · 02-02-2005, 07:51 PM

I thought that I read before that the 70 rear axle (6lug) is the same length as the 71-72 axles and that they are a direct swap. Anyone?

dropdprpls10 · 02-02-2005, 09:14 PM

Quote:

Originally Posted by Longhorn Man

Interesting that you have a 10 bolt....you might want to measure the width...these trucks never came with 10 bolt rears, so there is no telling what you have under there.
The difference between the early verses late is more liek 3/8 inch per side...not one inch.

you got me this is the first classic i have touched i have seen the 10 bolts under late model s-10 and blazers.. but i even double check and its a 10 bolt .. and i want something better so if anyone has a 12 bolt laying around i am looking for one to fix up!!!

72402 · 02-02-2005, 09:18 PM

I've also heard that the 70 axles are the same length as 71-72, but I don't know for sure. Frank

lukecp · 02-02-2005, 09:25 PM

Are you sure the 10-bolt isn't a Dana 44? I think they have 10 bolts on the cover and came in 67-68 GMC's.

lukecp · 02-02-2005, 09:32 PM

Also, some 1970 12-bolts are the same width as a 71-72 12-bolt and axleshafts will interchange.

I've got a pair of 1972 12-bolt 5-lug axleshafts if anyone wants to buy them....$50. PM me if anyone wants them.

Longhorn Man · 02-02-2005, 09:37 PM

yes, 70 was a chainge over year on the rear end..the early ones were like the older, the later ones were wider like the 71 & up.

Short68 · 02-02-2005, 09:38 PM

I am guessing it a Dana 44. It has 10 bolts and that whats under my 68 Chevy w/leafs.

72GMC51 · 02-02-2005, 09:44 PM

According to the hollander interchange the 70 - 72 axels on GM 12 bolts are 31-11/32" long and the 67-69 are 30-1/4".

gmc67swb · 02-02-2005, 10:20 PM

My '67 GMC has the Dana 44(10 bolt). I've pounded on it pretty good. Hasn't let me down yet. It's an 8.5" ring gear. Not sure what you want to use it for, but it should hold up pretty good. If you can get the truck to hook up, it may be a different story. I've done a couple of blasts with ET streets on mine (knock on wood) no probs yet.

fast_dev · 02-02-2005, 10:21 PM

you looking for 5 lug or 6?

dropdprpls10 · 02-02-2005, 10:40 PM

5 lug if i can find one but if not i can change a 6 lug do you have one?

Longhorn Man · 02-02-2005, 11:52 PM

Quote:

Originally Posted by 72GMC51

According to the hollander interchange the 70 - 72 axels on GM 12 bolts are 31-11/32" long and the 67-69 are 30-1/4".

I've proved those manuals wrong plenty of times...and stand by my previouse statement that the early ones were not as wide as the later ones.

flatblack67c-10 · 02-03-2005, 12:11 AM

I run the longer axles in my 67 housing, and use the wider drums with no problem.

dropdprpls10 · 02-06-2005, 10:53 AM

heres my next question ... im going to head to the local junk yards to see if i can find a 12 bolt rearend.. what other trucks can i pull them out of so it will fit in nicely.. im adding a 4 link so mounting hardware wont be a problem.. but length wise.. also how do i know if its posi.. i forget if its .. if you spinn the right wheel forward the left wheel will spin backwards.. is that for posi or not posi?? please help!?!?

junkyardjohn · 02-06-2005, 01:14 PM

Quote:

Originally Posted by dropdprpls10

heres my next question ... im going to head to the local junk yards to see if i can find a 12 bolt rearend.. what other trucks can i pull them out of so it will fit in nicely.. im adding a 4 link so mounting hardware wont be a problem.. but length wise.. also how do i know if its posi.. i forget if its .. if you spinn the right wheel forward the left wheel will spin backwards.. is that for posi or not posi?? please help!?!?

IF YOU SPIN EITHER SIDE... THE OTHER SIDE WILL SPIN IN THE SAME DIRECTION IF IT'S A POSI. IF YOUR ADDING A 4 LINC SETUP, WHY NOT GO WITH A 9" OUT OF A LATE 70s LINCOLN MARK IV??? THAT WAY YOU'D HAVE A BULLET PROOF REAREND WITH DISC BRAKES???

JOHN

dropdprpls10 · 02-06-2005, 03:49 PM

how hard is it to find one of those rear ends? and what will that set me back?

junkyardjohn · 02-06-2005, 08:06 PM

Quote:

Originally Posted by dropdprpls10

how hard is it to find one of those rear ends? and what will that set me back?

I PAID $100 BUCKS FOR 1 AT A PICK-N-PULL. THEN A FRIEND REBUILT IT. FIGURE ANOTHER $500 TO HAVE IT REBUILT & THE RING & PINION CHANGED.

JOHN

02-01-2005, 12:48 PM	#1
dropdprpls10 Registered User Join Date: Jun 2004 Location: Reading PA Posts: 164	question about rear ends a friend of mine has a 12 bolt chevy rear under his 67 chevy long bed.. it was a stock 6 lug pattern he went to the junk yard to get 5 lug axles .. he got them out of a 72.. when he went to put them in he says that they are an inch longer then his stock ones? is this a true statement or does he have something wrong.. i am asking because i have a 10 bolt on my 67 gmc and i want to put a 12 bolt in but dont want a wider one?? __________________ 98% of ALL fords are still on the road today... .... the other 2% made it home!!! where is the best place to park a ford???.. next to a fire station!!!! pictures of my new and old trucks!

02-01-2005, 01:05 PM	#2
junkyardjohn Registered User Join Date: Aug 2001 Location: SOMERSET KY. Posts: 6,425	YEP.. HE'S RIGHT. AXELS FROM A 67-70 ARE NOT INTERCHANGABLE WITH 71-72 AXELS. JOHN __________________ junkyardjohn 69 1 TON TOW TRUCK // 84 4WD CUCV BLAZER// 85 1 TON 4WD STAKE TRUCK// 86 M1031 5/4 TON 4WD CUCV// ALOT OF OLD TRUCKS FOR ONE OLD MAN TO DRIVE. THERES ROOM FOR ALL OF GODS CREATURES RIGHT NEXT TO MY MASHED POTATOES// LIFE MEMBER OF P.E.T.A (PEOPLE EATING TASTY ANIMALS) DON'T RENT U-HAUL ALWAYS TELL THE TRUTH IT WILL AMAZE PART OF THE PEOPLE & ASTONISH THE REST

02-01-2005, 02:13 PM	#3
dropdprpls10 Registered User Join Date: Jun 2004 Location: Reading PA Posts: 164	so i have to find a 67-70 12 bolt rear end then... thank you very much!!! __________________ 98% of ALL fords are still on the road today... .... the other 2% made it home!!! where is the best place to park a ford???.. next to a fire station!!!! pictures of my new and old trucks!

02-01-2005, 02:21 PM	#4
junkyardjohn Registered User Join Date: Aug 2001 Location: SOMERSET KY. Posts: 6,425	71 OR 72 REAR ENDS WILL FIT 67-70s. (THE WHOLE REAR END, NOT JUST THE AXELS)THE 1" PER SIDE IS NO BIG DEAL (EASILY MADE UP WITH BACKSPACING). THE 5 LUG HUBS MORE THAN MAKE UP FOR THE INCONVENIANCE. JOHN __________________ junkyardjohn 69 1 TON TOW TRUCK // 84 4WD CUCV BLAZER// 85 1 TON 4WD STAKE TRUCK// 86 M1031 5/4 TON 4WD CUCV// ALOT OF OLD TRUCKS FOR ONE OLD MAN TO DRIVE. THERES ROOM FOR ALL OF GODS CREATURES RIGHT NEXT TO MY MASHED POTATOES// LIFE MEMBER OF P.E.T.A (PEOPLE EATING TASTY ANIMALS) DON'T RENT U-HAUL ALWAYS TELL THE TRUTH IT WILL AMAZE PART OF THE PEOPLE & ASTONISH THE REST Last edited by junkyardjohn; 02-01-2005 at 02:24 PM.

02-01-2005, 11:31 PM	#6
68C15 blood type; Retumbo Join Date: Jan 2004 Location: next to my reloading bench Posts: 10,269	I will avoid any potentially embarrasing coments about rear ends. but I will say this, I think the difference can be made up for with different drums. get some measurements & head down to your FRIENDY (patient & knowledgable) parts store. in the book there is listings for part #'s based on these measurements. __________________ Man rule #77...if you own a 67 stepside with a caddy 472 you will never be in danger of loosing you man card

02-01-2005, 09:23 PM	#5
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Interesting that you have a 10 bolt....you might want to measure the width...these trucks never came with 10 bolt rears, so there is no telling what you have under there. The difference between the early verses late is more liek 3/8 inch per side...not one inch.

02-01-2005, 11:45 PM	#7
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	You can do that by using the 73 & later drums...HOWEVER... I said this on another forum, and some one pointed out that the bearings would be riding on a section NOT made for bearings, and that could be an issue. He also pointed out that since the bearings would be in further than designed, there would be more leverage on the axle shafts. After that being pointed out to me...I say don't try it.

02-02-2005, 07:51 PM	#8
Vince M Senior Member Join Date: Apr 2000 Location: Orlando, FL Posts: 1,076	I thought that I read before that the 70 rear axle (6lug) is the same length as the 71-72 axles and that they are a direct swap. Anyone? __________________ ............................................................ 68 Chevy CST SWB w/LS1, carb & 700r4. Golden Anniversary clone with a few improvements.

02-02-2005, 09:18 PM	#10
72402 Registered User Join Date: Nov 2004 Location: Cameron, Oklahoma Posts: 199	Axles I've also heard that the 70 axles are the same length as 71-72, but I don't know for sure. Frank

02-02-2005, 09:25 PM	#11
lukecp Formerly yellow72custom Join Date: May 2001 Location: Austin, TX Posts: 7,531	Are you sure the 10-bolt isn't a Dana 44? I think they have 10 bolts on the cover and came in 67-68 GMC's. __________________ '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

02-02-2005, 09:32 PM	#12
lukecp Formerly yellow72custom Join Date: May 2001 Location: Austin, TX Posts: 7,531	Also, some 1970 12-bolts are the same width as a 71-72 12-bolt and axleshafts will interchange. I've got a pair of 1972 12-bolt 5-lug axleshafts if anyone wants to buy them....$50. PM me if anyone wants them. __________________ '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

02-02-2005, 09:37 PM	#13
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	yes, 70 was a chainge over year on the rear end..the early ones were like the older, the later ones were wider like the 71 & up.

02-02-2005, 09:38 PM	#14
Short68 Registered User Join Date: Sep 2004 Location: Palestine TX Posts: 32	I am guessing it a Dana 44. It has 10 bolts and that whats under my 68 Chevy w/leafs.

02-02-2005, 09:44 PM	#15
72GMC51 72GMC51 Join Date: Jul 2004 Location: Minnesota Posts: 233	According to the hollander interchange the 70 - 72 axels on GM 12 bolts are 31-11/32" long and the 67-69 are 30-1/4". __________________ 72 GMC 2wd 1/2 long 350 700r4 A/C PS PB 4:10. Are they ever really finished

02-02-2005, 10:20 PM	#16
gmc67swb Registered User Join Date: Feb 2003 Location: Mesquite, Tx Posts: 396	My '67 GMC has the Dana 44(10 bolt). I've pounded on it pretty good. Hasn't let me down yet. It's an 8.5" ring gear. Not sure what you want to use it for, but it should hold up pretty good. If you can get the truck to hook up, it may be a different story. I've done a couple of blasts with ET streets on mine (knock on wood) no probs yet. __________________ GM 330HP/350, Magnuson 122HH, Tremec TKO 5spd



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02-02-2005, 10:21 PM	#17
fast_dev Registered User Join Date: Dec 2000 Location: Ringtown,PA Posts: 555	you looking for 5 lug or 6? __________________ 68 chevy 406 small block, budget drag racer, new best e.t 11.91 @112 67 nova numbers matching 327 4 speed 13.6 @ 102mph 70 longhorn c-30 402/4 speed 70 c-10 swb 402, muncie 4 speed 94 s-10 350/th350 3:73 posi 71 c-20 402/th400 towrig for racetruck. 72 4wd lifted on 35's 72 350/3 speed winter beater

02-02-2005, 10:40 PM	#18
dropdprpls10 Registered User Join Date: Jun 2004 Location: Reading PA Posts: 164	5 lug if i can find one but if not i can change a 6 lug do you have one? __________________ 98% of ALL fords are still on the road today... .... the other 2% made it home!!! where is the best place to park a ford???.. next to a fire station!!!! pictures of my new and old trucks!

02-03-2005, 12:11 AM	#20
flatblack67c-10 Registered User Join Date: Nov 2004 Location: Dover, AR Posts: 120	I run the longer axles in my 67 housing, and use the wider drums with no problem. __________________ was 67 chevy swb fleet now muticolored 69 step, 350/350, 3.73 posi, converted to 5 lug, torq thrust II 17x8 front 17x9.5 rear, factory air cab, fuel cell. future plans: shaved wiper cowl, shave stake pockets, phantom grille, and silver paint... 68 camaro ss396 project 54 f*rd project truck

02-06-2005, 10:53 AM	#21
dropdprpls10 Registered User Join Date: Jun 2004 Location: Reading PA Posts: 164	heres my next question ... im going to head to the local junk yards to see if i can find a 12 bolt rearend.. what other trucks can i pull them out of so it will fit in nicely.. im adding a 4 link so mounting hardware wont be a problem.. but length wise.. also how do i know if its posi.. i forget if its .. if you spinn the right wheel forward the left wheel will spin backwards.. is that for posi or not posi?? please help!?!? __________________ 98% of ALL fords are still on the road today... .... the other 2% made it home!!! where is the best place to park a ford???.. next to a fire station!!!! pictures of my new and old trucks!

02-06-2005, 03:49 PM	#23
dropdprpls10 Registered User Join Date: Jun 2004 Location: Reading PA Posts: 164	how hard is it to find one of those rear ends? and what will that set me back? __________________ 98% of ALL fords are still on the road today... .... the other 2% made it home!!! where is the best place to park a ford???.. next to a fire station!!!! pictures of my new and old trucks!

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