14 bolt GM right? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

70LongbedC20 · 06-25-2007, 04:14 PM

Hello,

I was just hoping that you experienced people could give me positive identification on the rearend that is under my 70 C20. As far as I can tell from looking around on the internet, it is a GM 14-bolt truck rearend that was installed in 3/4 ton trucks. I have 8 lugs on it, and 14 bolts holding the inspection cover on. I assume that I have 14 bolts holding the ring gear onto the carrier too but haven't confirmed that yet. I can't find any parts for it in the LMC catalog. According to their catalog, a 67-72 truck came with either a truck 12 bolt, a Dana 44 or a Dana 60. Can someone confirm for me that a 70 came with a 14 bolt? Is this a 14 bolt? Where can I get some parts? I know I need an inspection cover gasket.

How are these rear ends if it is a 14 bolt? Should I wish that I had a Dana? I think that I also read someplace that the 1-ton trucks also came with 14 bolt rear ends, but with the full floater setup. Is the ring and pinion the same? I have read a few posts about Eaton rearends, and I am not too familiar with them. Were they offered for this model year?

Thank you all in advance,
Alex

BCOWANWHEELS · 06-25-2007, 05:04 PM

Thats A Eaton Ho52 Rear

Imacarguytoo · 06-25-2007, 05:08 PM

Thats not a 14-bolt

Southedisto · 06-25-2007, 05:19 PM

Looks to me like a 14bolt semi floater, 9.5" ring gear. No where near the same as a 14 bolt full floater 10.5" ring gear.

Rust Buster · 06-25-2007, 06:00 PM

Looks like an Eaton to me, definitely not a 14 Bolt

Robert1970C20rstbukt · 06-25-2007, 07:01 PM

Count the bolts on the cover, it's a 14 bolt semi-floater like mentioned above. Eaton covers are completely round and smooth. The 9.5" semi-floaters don't have big hubs that stick out like a full floater has, it looks like a 1/2 ton axle shaft except for it having 8 lugs.Those axles are OK, but if you ever break an axle shaft for some reason or the C clip gets loose(hopefully never) it's gonna come out. On a full floater like a 10.5" 14 bolt if the axle breaks, the wheel stays on.

lukecp · 06-25-2007, 07:08 PM

That is a semi-floating 14 bolt, came in a lot of 80's and 90's 3/4 ton trucks. Most defenitly not an Eaton rear end.

67CHIP72 · 06-25-2007, 07:10 PM

Check this page out...

http://www.offroaders.com/info/tech-.../axlefacts.htm

*trkklr77* · 06-25-2007, 07:14 PM

the shaft are way bigger than a d60 anyways.

12b are only 5-6 lug

eatons are full floats only.

Southedisto · 06-26-2007, 12:44 AM

The shock mounts look like a newer style also.

70LongbedC20 · 06-26-2007, 01:44 AM

Okay thank you for everyone's input. So I guess it IS a 14 bolt and not an Eaton. Okay, now, can someone tell me IF these were every installed in 70 pickups? The very informative site that 67CHIP72 linked me to lists them as:

GM CORPORATE 14-BOLT
The "small" GM 14-bolt has a 9 1/2-inch ring gear diameter. It was used in the rear of 1964-and-later GM pickups, and in the rear of 1984-91 3/4-ton Suburbans.

Is this correct? Anyone else have one under their 67-72? Someone mentioned that the truck may have newer shock mounts, so I guess I am to assume that the axle is not original.

CrashEd · 06-26-2007, 02:15 AM

If it was out of a newer truck then the drivers side shock mount on the axle would of been cut off and welded to the front of the axle just like the passengers side. So if you cant see any grinding marks on the back side of the drivers side shock mount then i would say it come on the truck when new.
I got one under a 70 C/20 with a factory big block and it looks like its been there for a long time. I figured it had been changed at sometime because i didn't think thay were made tell the late 70s but this has got me wandering too now.
Ed

Southedisto · 06-26-2007, 02:20 AM

The more I look at it, the more it doesn't look like a 14bsf. Do you have a straight picture?

70LongbedC20 · 06-26-2007, 05:41 AM

I'll try to post another picture when I get home after work. Do you need a picture from drum to drum?

Thanks,
Alex

OLDCHEV4X4 · 06-26-2007, 07:22 AM

looks like the rear in my 1986 gmc 3/4 ton. 14bolt semi floating. Wouldn't there be numbers stamped on the top of the right axle tube??

Southedisto · 06-26-2007, 12:58 PM

Quote:

Originally Posted by 70LongbedC20

I'll try to post another picture when I get home after work. Do you need a picture from drum to drum?

Thanks,
Alex

A straight on shot from the rear so you can see the diff cover straight on, would be ideal.

70LongbedC20 · 06-26-2007, 01:37 PM

Here you go. Hope this one. Thanks alot for the help!!!!!!

OLDCHEV4X4 · 06-26-2007, 02:45 PM

I don't know......kinda looks like a sf 14 bolt cover.....whats that line going down the middle of the cover?

70LongbedC20 · 06-26-2007, 03:19 PM

Quote:

Originally Posted by CrashEd

If it was out of a newer truck then the drivers side shock mount on the axle would of been cut off and welded to the front of the axle just like the passengers side. So if you cant see any grinding marks on the back side of the drivers side shock mount then i would say it come on the truck when new.
I got one under a 70 C/20 with a factory big block and it looks like its been there for a long time. I figured it had been changed at sometime because i didn't think thay were made tell the late 70s but this has got me wandering too now.
Ed

There might be some truth to this, will have to inspect a little closer. I don't really see any grinding marks, but there may be a difference in weld qualities.

70LongbedC20 · 06-26-2007, 03:20 PM

Quote:

Originally Posted by OLDCHEV4X4

I don't know......kinda looks like a sf 14 bolt cover.....whats that line going down the middle of the cover?

The line down the middle is just a hump built in for the ring gear like on a 12 bolt.

Rust Buster · 06-26-2007, 04:21 PM

Yup, I was wrong, definitely not the first time! That angle clearly shows it's not an Eaton.

Southedisto · 06-26-2007, 11:39 PM

14 bolt semi floater for sure.

1969k10stepside · 06-26-2007, 11:39 PM

14 Bolt Semi Floater..not stock to 67-72s

70LongbedC20 · 06-26-2007, 11:50 PM

Thank you to everyone!

Cheers,
Alex

Morgsie · 06-27-2007, 01:52 AM

Does this mean that ALL 14b Full-Floaters have this cover?

06-25-2007, 04:14 PM	#1
70LongbedC20 Registered User Join Date: Feb 2007 Location: France Posts: 53	14 bolt GM right? Hello, I was just hoping that you experienced people could give me positive identification on the rearend that is under my 70 C20. As far as I can tell from looking around on the internet, it is a GM 14-bolt truck rearend that was installed in 3/4 ton trucks. I have 8 lugs on it, and 14 bolts holding the inspection cover on. I assume that I have 14 bolts holding the ring gear onto the carrier too but haven't confirmed that yet. I can't find any parts for it in the LMC catalog. According to their catalog, a 67-72 truck came with either a truck 12 bolt, a Dana 44 or a Dana 60. Can someone confirm for me that a 70 came with a 14 bolt? Is this a 14 bolt? Where can I get some parts? I know I need an inspection cover gasket. How are these rear ends if it is a 14 bolt? Should I wish that I had a Dana? I think that I also read someplace that the 1-ton trucks also came with 14 bolt rear ends, but with the full floater setup. Is the ring and pinion the same? I have read a few posts about Eaton rearends, and I am not too familiar with them. Were they offered for this model year? Thank you all in advance, Alex Attached Images

06-25-2007, 05:04 PM	#2
BCOWANWHEELS Registered User Join Date: Nov 2006 Location: KINGSPORT,TN. Posts: 3,035	Re: 14 bolt GM right? Thats A Eaton Ho52 Rear __________________ I BELIEVE IN JOHN 3:16

06-25-2007, 05:08 PM	#3
Imacarguytoo Registered User Join Date: Nov 2006 Location: Illinois Posts: 306	Re: 14 bolt GM right? Thats not a 14-bolt __________________ '67 C20 Lwb 350 4-Speed '01 Chrysler Concorde LXI (wifes ride) '91 Gmc Suburban 3/4 2wd 454 Tbi '51 Jeep Cj3a "Willys" 350 V8

06-25-2007, 05:19 PM	#4
Southedisto River life...... Join Date: Oct 2005 Location: Orangeburg SC Posts: 1,078	Re: 14 bolt GM right? Looks to me like a 14bolt semi floater, 9.5" ring gear. No where near the same as a 14 bolt full floater 10.5" ring gear. __________________ I like wheelin in Dixie!

06-25-2007, 06:00 PM	#5
Rust Buster Registered User Join Date: Apr 2007 Location: Virginia Posts: 547	Re: 14 bolt GM right? Looks like an Eaton to me, definitely not a 14 Bolt __________________ Maj USAF 71 K5 Blazer CST 72 K20 HT383 NV4500 Mass-Flo EFI 71 K10 LWB 52 Dodge Power Wagon 67 Dodge WM300 Power Wagon 48 Dodge WDX Power Wagon My Build Thread http://67-72chevytrucks.com/vboard/s...d.php?t=239487

06-25-2007, 07:01 PM	#6
Robert1970C20rstbukt Registered User Join Date: Jun 2004 Location: Beeville, Texas Posts: 1,943	Re: 14 bolt GM right? Count the bolts on the cover, it's a 14 bolt semi-floater like mentioned above. Eaton covers are completely round and smooth. The 9.5" semi-floaters don't have big hubs that stick out like a full floater has, it looks like a 1/2 ton axle shaft except for it having 8 lugs.Those axles are OK, but if you ever break an axle shaft for some reason or the C clip gets loose(hopefully never) it's gonna come out. On a full floater like a 10.5" 14 bolt if the axle breaks, the wheel stays on. __________________ RJD 1984 Chevrolet C30 welding truck 454/SM465 1977 GMC C15 pickup 350/TH350 1970 Chevrolet C20 pickup 350/TH400 1970 Chevrolet K20 Suburban 454/TH350 1969 GMC 8500 478M V6/5 spd winch truck

06-25-2007, 07:08 PM	#7
lukecp Formerly yellow72custom Join Date: May 2001 Location: Austin, TX Posts: 7,531	Re: 14 bolt GM right? That is a semi-floating 14 bolt, came in a lot of 80's and 90's 3/4 ton trucks. Most defenitly not an Eaton rear end. __________________ '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

06-25-2007, 07:10 PM	#8
67CHIP72 STOLEN Join Date: Jun 2006 Location: Orange County Posts: 1,022	Re: 14 bolt GM right? Check this page out... http://www.offroaders.com/info/tech-.../axlefacts.htm __________________ In Search Of

06-25-2007, 07:14 PM	#9
trkklr77 Account Suspended Join Date: Aug 2006 Location: vacaville ca, because it as far from indy as i can be Posts: 777	Re: 14 bolt GM right? the shaft are way bigger than a d60 anyways. 12b are only 5-6 lug eatons are full floats only.

06-26-2007, 12:44 AM	#10
Southedisto River life...... Join Date: Oct 2005 Location: Orangeburg SC Posts: 1,078	Re: 14 bolt GM right? The shock mounts look like a newer style also. __________________ I like wheelin in Dixie!

06-26-2007, 01:44 AM	#11
70LongbedC20 Registered User Join Date: Feb 2007 Location: France Posts: 53	Re: 14 bolt GM right? Okay thank you for everyone's input. So I guess it IS a 14 bolt and not an Eaton. Okay, now, can someone tell me IF these were every installed in 70 pickups? The very informative site that 67CHIP72 linked me to lists them as: GM CORPORATE 14-BOLT The "small" GM 14-bolt has a 9 1/2-inch ring gear diameter. It was used in the rear of 1964-and-later GM pickups, and in the rear of 1984-91 3/4-ton Suburbans. Is this correct? Anyone else have one under their 67-72? Someone mentioned that the truck may have newer shock mounts, so I guess I am to assume that the axle is not original.

06-26-2007, 02:15 AM	#12
CrashEd 72 chevy Join Date: Jan 2007 Location: Central Il Posts: 725	Re: 14 bolt GM right? If it was out of a newer truck then the drivers side shock mount on the axle would of been cut off and welded to the front of the axle just like the passengers side. So if you cant see any grinding marks on the back side of the drivers side shock mount then i would say it come on the truck when new. I got one under a 70 C/20 with a factory big block and it looks like its been there for a long time. I figured it had been changed at sometime because i didn't think thay were made tell the late 70s but this has got me wandering too now. Ed Last edited by CrashEd; 06-26-2007 at 02:20 AM. Reason: minds going fast

06-26-2007, 02:20 AM	#13
Southedisto River life...... Join Date: Oct 2005 Location: Orangeburg SC Posts: 1,078	Re: 14 bolt GM right? The more I look at it, the more it doesn't look like a 14bsf. Do you have a straight picture? __________________ I like wheelin in Dixie!

06-26-2007, 05:41 AM	#14
70LongbedC20 Registered User Join Date: Feb 2007 Location: France Posts: 53	Re: 14 bolt GM right? I'll try to post another picture when I get home after work. Do you need a picture from drum to drum? Thanks, Alex

06-26-2007, 07:22 AM	#15
OLDCHEV4X4 Registered User Join Date: Apr 2000 Location: Chester County PA, USA Posts: 1,228	Re: 14 bolt GM right? looks like the rear in my 1986 gmc 3/4 ton. 14bolt semi floating. Wouldn't there be numbers stamped on the top of the right axle tube?? __________________ 72 k/10 short wideside 72 k/5 Blazer 72 K/5 Blazer - obstacle course racer 72 custom/10 8' bed 70 K/5 Blazer 67 C-30 GMC Flat bed 86 GMC K2500 Plow Truck 85 GMC K3500 84 M1008 85 M1008 77 G30 Motor Home 72 Sears 12hp Tractor Glenmoore, Pennsylvania



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06-26-2007, 01:37 PM	#17
70LongbedC20 Registered User Join Date: Feb 2007 Location: France Posts: 53	Re: 14 bolt GM right? Here you go. Hope this one. Thanks alot for the help!!!!!! Attached Images

06-26-2007, 02:45 PM	#18
OLDCHEV4X4 Registered User Join Date: Apr 2000 Location: Chester County PA, USA Posts: 1,228	Re: 14 bolt GM right? I don't know......kinda looks like a sf 14 bolt cover.....whats that line going down the middle of the cover? __________________ 72 k/10 short wideside 72 k/5 Blazer 72 K/5 Blazer - obstacle course racer 72 custom/10 8' bed 70 K/5 Blazer 67 C-30 GMC Flat bed 86 GMC K2500 Plow Truck 85 GMC K3500 84 M1008 85 M1008 77 G30 Motor Home 72 Sears 12hp Tractor Glenmoore, Pennsylvania

06-26-2007, 04:21 PM	#21
Rust Buster Registered User Join Date: Apr 2007 Location: Virginia Posts: 547	Re: 14 bolt GM right? Yup, I was wrong, definitely not the first time! That angle clearly shows it's not an Eaton. __________________ Maj USAF 71 K5 Blazer CST 72 K20 HT383 NV4500 Mass-Flo EFI 71 K10 LWB 52 Dodge Power Wagon 67 Dodge WM300 Power Wagon 48 Dodge WDX Power Wagon My Build Thread http://67-72chevytrucks.com/vboard/s...d.php?t=239487

06-26-2007, 11:39 PM	#22
Southedisto River life...... Join Date: Oct 2005 Location: Orangeburg SC Posts: 1,078	Re: 14 bolt GM right? 14 bolt semi floater for sure. __________________ I like wheelin in Dixie!

06-26-2007, 11:39 PM	#23
1969k10stepside Registered User Join Date: Mar 2006 Location: USA Posts: 21,020	Re: 14 bolt GM right? 14 Bolt Semi Floater..not stock to 67-72s Last edited by 1969k10stepside; 06-26-2007 at 11:40 PM.

06-26-2007, 11:50 PM	#24
70LongbedC20 Registered User Join Date: Feb 2007 Location: France Posts: 53	Re: 14 bolt GM right? Thank you to everyone! Cheers, Alex

06-27-2007, 01:52 AM	#25
Morgsie Registered User Join Date: Apr 2005 Location: BC, Canada Posts: 122	Re: 14 bolt GM right? Does this mean that ALL 14b Full-Floaters have this cover?

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