Sourcing a 12 bolt - The 1947 - Present Chevrolet & GMC Truck Message Board Network

orange72350 · 03-19-2004, 01:32 AM

ok, so its rearend replacemnt time i think. my truck bangs realy bad when i hit the thottle at mid-high rpms, and when i shift it from neutral to park. anyhoo, what is the easiest route to go here? i have all the tools imaginable available to me, and a huge shop to do this in. Should i just find a junkyard 12 bolt? If i do this and the donor vehicle is different, do showckmounts and spring perches need to be fabbed up or anything like that? Or, is it easier to find a ford nine inch? i have welding skill, and about a weekend to do this. Or, should i rebuild this diff? how difficult is a rebuild? I have done engines and trannys, but never a diff. Posi isnt a big deal, it is nice though. Any thoughts and or suggestions are very much welcome. thanx guyz

**smitty62** · 03-19-2004, 01:44 AM

Have you checked all the U-joints? If not, suggest you do that first.

orange72350 · 03-19-2004, 11:42 AM

u-joints are all brande new, its definelty the diff going out., ttt

lukecp · 03-21-2004, 12:05 AM

First pop off the cover and see what is up. If a bunch of metal is in the fluid, you know that is the problem.

A junkyard rear is the easiest solution, however i have had bad experiences with (bought a junk one). You can swap out the rear in a day no problem, its pretty easy. Just remove the driveshaft from the yolk, remove the rubber brake line going to the rear from the frame, and unbolt the rear (will proably have to cut the U-bolts if they are original), and it comes right out. Nothing to it.

I hope to rebuild my 12-bolt eventually when i have the time/money, check this post i made here:

http://67-72chevytrucks.com/vboard/...&threadid=84975

And this:
http://www.drivetrain.com/ringpinioninstal.html

03-19-2004, 01:32 AM	#1
orange72350 Registered User Join Date: Jan 2003 Location: Cold, Snowy High Level, Alberta Canada Eh Posts: 394	Sourcing a 12 bolt ok, so its rearend replacemnt time i think. my truck bangs realy bad when i hit the thottle at mid-high rpms, and when i shift it from neutral to park. anyhoo, what is the easiest route to go here? i have all the tools imaginable available to me, and a huge shop to do this in. Should i just find a junkyard 12 bolt? If i do this and the donor vehicle is different, do showckmounts and spring perches need to be fabbed up or anything like that? Or, is it easier to find a ford nine inch? i have welding skill, and about a weekend to do this. Or, should i rebuild this diff? how difficult is a rebuild? I have done engines and trannys, but never a diff. Posi isnt a big deal, it is nice though. Any thoughts and or suggestions are very much welcome. thanx guyz __________________ 2003 yamaha raptor. Stock, but it still hauls!!!! 2000 skiddo mxz 700. Camoplast 1.5 inch track, jaws twin pipes, b+b can, custom built and weighted clutch, wiseco piston, high comp heads. its very fast. wow. 72 c-10 longbox. Bright Orange. Brand new 350, rv cam, performer intake, qjet, headers, 2 1/2 inch exhaust into hooker areo chamber mufflers. Body work coming soon. "dont let yer mind wander, its to little to go places by itself." "Forget the herse, cause i'll never die"-ACDC Back In Black "If It's To Loud, Yer Just Too Old" "I Love Anything Fast Enough To Do Something Stupid In" "Instant idiot, just add beer!!""

03-19-2004, 01:44 AM	#2
smitty62 Registered User Join Date: May 2002 Location: North Carolina Posts: 1,234	Have you checked all the U-joints? If not, suggest you do that first. __________________ Stepsides look like real trucks! Smitty

03-19-2004, 11:42 AM	#3
orange72350 Registered User Join Date: Jan 2003 Location: Cold, Snowy High Level, Alberta Canada Eh Posts: 394	u-joints are all brande new, its definelty the diff going out., ttt __________________ 2003 yamaha raptor. Stock, but it still hauls!!!! 2000 skiddo mxz 700. Camoplast 1.5 inch track, jaws twin pipes, b+b can, custom built and weighted clutch, wiseco piston, high comp heads. its very fast. wow. 72 c-10 longbox. Bright Orange. Brand new 350, rv cam, performer intake, qjet, headers, 2 1/2 inch exhaust into hooker areo chamber mufflers. Body work coming soon. "dont let yer mind wander, its to little to go places by itself." "Forget the herse, cause i'll never die"-ACDC Back In Black "If It's To Loud, Yer Just Too Old" "I Love Anything Fast Enough To Do Something Stupid In" "Instant idiot, just add beer!!""

03-21-2004, 12:05 AM	#4
lukecp Formerly yellow72custom Join Date: May 2001 Location: Austin, TX Posts: 7,531	First pop off the cover and see what is up. If a bunch of metal is in the fluid, you know that is the problem. A junkyard rear is the easiest solution, however i have had bad experiences with (bought a junk one). You can swap out the rear in a day no problem, its pretty easy. Just remove the driveshaft from the yolk, remove the rubber brake line going to the rear from the frame, and unbolt the rear (will proably have to cut the U-bolts if they are original), and it comes right out. Nothing to it. I hope to rebuild my 12-bolt eventually when i have the time/money, check this post i made here: http://67-72chevytrucks.com/vboard/...&threadid=84975 And this: http://www.drivetrain.com/ringpinioninstal.html __________________ '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



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