How to dismantle an a 12 Bolt? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**1971Stepside** · 09-05-2002, 10:06 AM

OK, I used all of the great advice yesterday on how to get the drums off....and it worked. Now I need to pull the axles and the carrier. I am going to have the axle powder coated and it needs to be bare to do so. I hate to pull it apart because it will cost me a fortune to put back together (want a posi) but I really want it coated at the same time the frame gets it.

Do any of you have a step by step on how to pull this thing apart. It is a 373 12 bolt. Thanks for your help.

71BBK10 · 09-05-2002, 10:15 AM

ok, theres a little bolt the holds in the cross bolt that goes through the middle of the carrier, take that out, take the cross bolt out, push axles in towards the center of the carrier so you can get the c clips out, pull those out, pull the axles out. then remove the 2 bolts on each main cap and it should pop out. don't think i'm forgetting anything but if i am i'm sure somebody will correct me. good luck and be careful, that sucker is heavy.

71BBK10 · 09-05-2002, 10:25 AM

one more thing i forgot, make sure you use a punch or something to mark which side the bearing caps came off of, don't want to mix them.

JimKshortstep4x4 · 09-05-2002, 10:47 AM

If you need to pull the pinion, I would break the pinion nut loose before disassembly of the carrier unless you have one of these really big wrenches to hold the companion flange. They are torqued to 200 plus lb. ft. and can be tough to break loose.

If you have to remove the pinion, remove the nut and companion flange and the pinion will tap out, after the carrier is removed. I usually take the seal and bearing out before tapping out the pinion with a lead hammer.

Jim

**1971Stepside** · 09-05-2002, 11:34 AM

OK sounds good so far, but you guys are using names that I have never heard of......hmmm this is my first time even looking inside of an axle. I consider myself pretty mechanically inclined, but this is all new.

71BBK10 · 09-05-2002, 11:59 AM

its fairly simple tearing it apart, you'll understand what i mean with the cross bolt, it goes right through the center of the carrier and the c clips are at the ends of each axleshaft. once you learn how to do one they are almost all the same, except full floaters and a 9 inch ford. good luck

jku72 · 09-05-2002, 01:21 PM

Get a manual, then study it. It is well worth 30 bucks to get one, with illustrations and all. Most any vendor has 67-72 service and overhaul manuals, they will save you in this job, and many you havent thought of. Telling you isnt going to work to well, you need a reference to go through throughout the job.

**1971Stepside** · 09-06-2002, 09:23 AM

Wow! That was much easier than I thought it would be. I followed your steps 71BBK10 and it went very smooth. She is ready for a little oven cleaner and then off to the sand blaster!

71BBK10 · 09-06-2002, 09:56 AM

glad to hear it

BobbyK · 09-06-2002, 06:56 PM

Here's a couple pic's of my 12 bolt.I have an Eaton Gov Loc(posi) but it's basically the same with an open diff.
-Take cover off and drain that stinky diff. oil.

-Remove this bolt so you can remove the pinion shaft.

-The pinion shaft is the rod by my thumb.You must remove the pinion shaft to get access to the "C" clips.

-The "C" clips retain the axles in the housing.Go to the wheel end of the axle and push the axles in.You will now be able to remove the "C" clips and simply pull axles out.

Can't help with the rest as I've never removed the innards of a diff. before.
I sure someone else can explain that.
Hope the pic's help.

BobbyK · 09-06-2002, 07:02 PM

Damn...I got to start reading ALL the posts.He had already stripped the pumkin before I posted the pic's.Jeez!
Sorry about that.

Brad · 09-06-2002, 08:45 PM

The pics will help me, BobbyK! I plan on doing this soon. This article should go in the FAQ section.

09-05-2002, 10:06 AM	#1
1971Stepside Almost Satisfied Join Date: Mar 2002 Location: Springfield, MO Posts: 2,928	How to dismantle an a 12 Bolt? OK, I used all of the great advice yesterday on how to get the drums off....and it worked. Now I need to pull the axles and the carrier. I am going to have the axle powder coated and it needs to be bare to do so. I hate to pull it apart because it will cost me a fortune to put back together (want a posi) but I really want it coated at the same time the frame gets it. Do any of you have a step by step on how to pull this thing apart. It is a 373 12 bolt. Thanks for your help. __________________ 1971 C10 Stepside. LSx 6.0 with BTR Stage IV, Speed Engineering Headers, 4L80e transmission w/3200 Circle-D Stall. 3.73. Posi. Purchased this truck when I was 17. I started the rebuild (or take apart) in 1993. I have drug it around all over the country in pieces. Finally back on the road in 2021. "I can't complain, but sometimes I still do. Life's been good to me so far."

09-05-2002, 10:15 AM	#2
71BBK10 Teufelhunden Join Date: Oct 2001 Location: Camp Pendelton Ca Posts: 572	ok, theres a little bolt the holds in the cross bolt that goes through the middle of the carrier, take that out, take the cross bolt out, push axles in towards the center of the carrier so you can get the c clips out, pull those out, pull the axles out. then remove the 2 bolts on each main cap and it should pop out. don't think i'm forgetting anything but if i am i'm sure somebody will correct me. good luck and be careful, that sucker is heavy. __________________ 1971 K10 lwb fleetside 402 T350 205

09-05-2002, 10:25 AM	#3
71BBK10 Teufelhunden Join Date: Oct 2001 Location: Camp Pendelton Ca Posts: 572	one more thing i forgot, make sure you use a punch or something to mark which side the bearing caps came off of, don't want to mix them. __________________ 1971 K10 lwb fleetside 402 T350 205

09-05-2002, 11:34 AM	#5
1971Stepside Almost Satisfied Join Date: Mar 2002 Location: Springfield, MO Posts: 2,928	OK sounds good so far, but you guys are using names that I have never heard of......hmmm this is my first time even looking inside of an axle. I consider myself pretty mechanically inclined, but this is all new. __________________ 1971 C10 Stepside. LSx 6.0 with BTR Stage IV, Speed Engineering Headers, 4L80e transmission w/3200 Circle-D Stall. 3.73. Posi. Purchased this truck when I was 17. I started the rebuild (or take apart) in 1993. I have drug it around all over the country in pieces. Finally back on the road in 2021. "I can't complain, but sometimes I still do. Life's been good to me so far."

09-05-2002, 11:59 AM	#6
71BBK10 Teufelhunden Join Date: Oct 2001 Location: Camp Pendelton Ca Posts: 572	its fairly simple tearing it apart, you'll understand what i mean with the cross bolt, it goes right through the center of the carrier and the c clips are at the ends of each axleshaft. once you learn how to do one they are almost all the same, except full floaters and a 9 inch ford. good luck __________________ 1971 K10 lwb fleetside 402 T350 205

09-05-2002, 10:47 AM	#4
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	If you need to pull the pinion, I would break the pinion nut loose before disassembly of the carrier unless you have one of these really big wrenches to hold the companion flange. They are torqued to 200 plus lb. ft. and can be tough to break loose. If you have to remove the pinion, remove the nut and companion flange and the pinion will tap out, after the carrier is removed. I usually take the seal and bearing out before tapping out the pinion with a lead hammer. Jim

09-05-2002, 01:21 PM	#7
jku72 Registered User Join Date: Jan 2002 Location: cornville, maine Posts: 659	Get a manual, then study it. It is well worth 30 bucks to get one, with illustrations and all. Most any vendor has 67-72 service and overhaul manuals, they will save you in this job, and many you havent thought of. Telling you isnt going to work to well, you need a reference to go through throughout the job. __________________ jku Cornville, Maine 68 C10 burb 42 Willys MB 46 Dodge WF-32 1.5 ton 53 & 56 Olds' 60 Cadillac 22 Dodge Brothers

09-06-2002, 09:23 AM	#8
1971Stepside Almost Satisfied Join Date: Mar 2002 Location: Springfield, MO Posts: 2,928	Wow! That was much easier than I thought it would be. I followed your steps 71BBK10 and it went very smooth. She is ready for a little oven cleaner and then off to the sand blaster! __________________ 1971 C10 Stepside. LSx 6.0 with BTR Stage IV, Speed Engineering Headers, 4L80e transmission w/3200 Circle-D Stall. 3.73. Posi. Purchased this truck when I was 17. I started the rebuild (or take apart) in 1993. I have drug it around all over the country in pieces. Finally back on the road in 2021. "I can't complain, but sometimes I still do. Life's been good to me so far."

09-06-2002, 09:56 AM	#9
71BBK10 Teufelhunden Join Date: Oct 2001 Location: Camp Pendelton Ca Posts: 572	glad to hear it __________________ 1971 K10 lwb fleetside 402 T350 205

09-06-2002, 06:56 PM	#10
BobbyK Registered User Join Date: May 2000 Location: Petrolia,Ontario,Canada but working in Port Huron,Mi. Posts: 1,769	Here's a couple pic's of my 12 bolt.I have an Eaton Gov Loc(posi) but it's basically the same with an open diff. -Take cover off and drain that stinky diff. oil. -Remove this bolt so you can remove the pinion shaft. -The pinion shaft is the rod by my thumb.You must remove the pinion shaft to get access to the "C" clips. -The "C" clips retain the axles in the housing.Go to the wheel end of the axle and push the axles in.You will now be able to remove the "C" clips and simply pull axles out. Can't help with the rest as I've never removed the innards of a diff. before. I sure someone else can explain that. Hope the pic's help. __________________ 71 blazer,350SBC,approx.375HP,700R4,factory GM TPI.Dual electric fans,33x12.5x15 ATR on stock suspension. Petrolia,Ontario,Canada but working in Port Huron,MI. See ALL my Blazer pic's HERE Last edited by BobbyK; 09-06-2002 at 06:59 PM.

09-06-2002, 07:02 PM	#11
BobbyK Registered User Join Date: May 2000 Location: Petrolia,Ontario,Canada but working in Port Huron,Mi. Posts: 1,769	Damn...I got to start reading ALL the posts.He had already stripped the pumkin before I posted the pic's.Jeez! Sorry about that. __________________ 71 blazer,350SBC,approx.375HP,700R4,factory GM TPI.Dual electric fans,33x12.5x15 ATR on stock suspension. Petrolia,Ontario,Canada but working in Port Huron,MI. See ALL my Blazer pic's HERE

09-06-2002, 08:45 PM	#12
Brad Out of the carpool lane. Join Date: Jan 2000 Location: Clark Co, WA Posts: 5,673	The pics will help me, BobbyK! I plan on doing this soon. This article should go in the FAQ section. __________________ 1968 C-10 SWB, 5.7 Vortec/700R4/3.73 posi, Torch Red 1968 Camaro, 250/Powerglide, all original (No, I'm not gonna drop a 350 in it!...Jeez!) 2000 Honda VFR in the faster yellow! 2008 Husqvarna TE-610 1967 C-10 SWB 'Six Appeal'-Gone but not forgotten...



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