![]() |
Register or Log In To remove these advertisements. |
|
|
![]() |
|
Thread Tools | Display Modes |
![]() |
#1 |
Registered User
Join Date: Nov 2011
Location: Jones Creek, Texas
Posts: 38
|
how tough are our rearends
how tough are 67-72 rearends? Not exactly sure what year i have, truck is a 67 but i have 5 lug axles and disc brakes in the front that matched up perfectly with 72 calipers when i had to replace. i have 3.73 gears, so back to the question how tough are these rearends?
|
![]() |
![]() |
![]() |
#2 |
What?
Join Date: Jun 2007
Location: Southern California
Posts: 7,617
|
Re: how tough are our rearends
Mine has been kicked around so many times these past 40+ years, I sometimes feel like super man since I am still kicking other rear ends and takin names...
![]() To answer your question. Some of the toughest around, and still highly regarded as a standard when it comes to strength.
__________________
Chris 1968 K20 Suburban 1972 K10 LWB PU |
![]() |
![]() |
![]() |
#3 |
Hittin E-Z Street on Mud Tires
![]() Join Date: Nov 2004
Location: Greenville, SC
Posts: 23,090
|
Re: how tough are our rearends
Mine has probably over 200K on it, it's almost 45 years old, and when I changed the fluid a couple years ago there were NO visible signs of wear or leaks! Seems pretty tough to me.
__________________
Jesse James 1967 C10 SWB Stepside: 350/700R4/3.73 1965 Ford Mustang: 289/T5-5spd/3.25 Trac-Loc 1968 Pontiac Firebird: Project Fire Chicken! 2015 Silverado Double Cab 5.3L Z71 2001 Jeep Wrangler Sport 4.0L 5spd 2020 Chevrolet Equinox Premium 2.0L Turbo 2011 Mustang V6 ~ Wife's ride ![]() American Born, Country by the Grace of God ![]() 1967 CST Shop Truck Rebuild! My 1967 C-10 Build Thread My Vintage Air A/C Install Project "On a Dime" Trying my hand at Home Renovation! 1965 Mustang Modifications! |
![]() |
![]() |
![]() |
#4 |
Registered User
Join Date: Nov 2011
Location: Jones Creek, Texas
Posts: 38
|
Re: how tough are our rearends
good to know, thnx
|
![]() |
![]() |
![]() |
#5 |
Grandpa in the rustmobile...
Join Date: Nov 2008
Location: Spokane WA/Viola TN
Posts: 11,422
|
Re: how tough are our rearends
still running an original rearend from a 72 from a guy off the forum here.
changed oil and put new rtv on thats all so far
__________________
John Goose-1968 C10 355,9.32-1CR, Vortec Heads ,262 voodoo, 3.73:1 3OTT (HS ride/beater/farm truck) http://67-72chevytrucks.com/vboard/s...d.php?t=317684 Grams 53-1953 Chevrolet Belair http://67-72chevytrucks.com/vboard/s...=1#post4327784 1969 Chevy C10 Shortbed 4.5/6?" Frame off resto http://67-72chevytrucks.com/vboard/s...d.php?t=548136 1999 Toyota Tacoma 4x4 |
![]() |
![]() |
![]() |
#6 |
My Carbon Footprint
Join Date: Oct 2008
Location: Orygun
Posts: 5,527
|
Re: how tough are our rearends
My rear end is pretty tough........and according to my wife.......quite stinky at times!
|
![]() |
![]() |
![]() |
#7 |
Registered User
Join Date: Dec 2011
Location: Savannah, GA
Posts: 104
|
Re: how tough are our rearends
Ill assume we are talking about 1/2 ton rears since the 3/4 and 1 ton rears are so tough I think their reputation speaks for itself.
A lot of the 4x4 crowd will likes to say C clip axles are not worth a salt but I have never had on go bad on me. The 12 bolt rears that were put in 396 Camaros have stood up excellently to the high torque that engine is capable of producing. On to trucks though, my only real experience is, once again, with 12 bolts and like I said, I have never had on malfunction in any way from anything I have done to it. 4wd and 2wd applications. |
![]() |
![]() |
![]() |
#8 |
Account Suspended
Join Date: Dec 2011
Location: ma
Posts: 278
|
Re: how tough are our rearends
a few thoughts..
the truck 12 bolt is not the same as the 12 bolt under a camaro or chevelle.. the truck 12 bolt is stong.. untill you slap slicks on it.. and beat on it... the truck 12 bolt has a smaller pinion shaft o.d. than the car, why g.m. did this.. who knows.. there are other differences, from what I've heard the car diff will not work in the truck housing.. my understanding is they are a little stonger than a chevy 10 bolt, but weaker than the car 12 bolt.. still mighty strong. but wasn't made for todays big block power levels.. also remember back in the late 60's early 70's tires didn't have the grip they have today.. todays goodyear eagles street gator backs have more hook than most recapped slicks of the day.. nevermind todays drag radials.. or heaven forbid slicks.. only reason manual trannys lasted back then is because the tires where the weal link.. |
![]() |
![]() |
![]() |
#9 |
Senior Member
Join Date: Jan 2003
Location: daytonabeach
Posts: 22,956
|
Re: how tough are our rearends
12bolt truck rears will not last but 2seconds in a top fuel car// many lasted over 45 years and are still going strong in warmed up vehicles with bonzai driving
so it all really depends on horspower, tires, abuse and other factors / none of which was addressessed in the original question
__________________
71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY |
![]() |
![]() |
![]() |
#10 |
Registered User
Join Date: Aug 2005
Location: Pasadena,Tx /Pto Pta DR
Posts: 5,415
|
Re: how tough are our rearends
pretty tough for a stock vehicle considering how much care most owners did NOT give them. for racing no. they lasted this long
|
![]() |
![]() |
![]() |
#11 | ||
"I ain't nobody, dork."
Join Date: Sep 2007
Location: Whidbey Island, Washington
Posts: 8,940
|
Re: how tough are our rearends
Mine in my 1972 GMC C1500 Super Custom has an Eaton posi, 3.73's, and Moser axles. I beat the snot out of it. Comes back for more...
Gary
__________________
'cuz chicks dig scars... My 1972 GMC 1500 Super Custom (Creeping Death) "long term" build thread. The Rebuild of Creeping Death after the wreck Quote:
Quote:
|
||
![]() |
![]() |
![]() |
#12 |
Senior Member
![]() Join Date: Dec 2006
Location: Studio City, Calif.
Posts: 2,873
|
Re: how tough are our rearends
If we're talking 1/2 tons, my last '69 had a 350 engine with a serious RV cam that developed unbelievable torque. Load the truck with a couple yards of wet decomposed granite, select granny low (6.55-1) and floor it. Broke a few U-joints in it but never had a diff. problem in 6 years of use and abuse.
Same story with the current 3/4 ton without the U-joint problems.
__________________
'69 GMC C2500 Custom Camper, 8 1/2' bed, New GM 350, NP 435 Close Ratio 4spd. Trans., 3.73 Dana-60 open.Camper and Trailer wiring, PS, PB, AC, tach , three gas tanks, stereo speakers, 2nd owner, Work-Truck supreme. |
![]() |
![]() |
![]() |
#13 |
Registered User
Join Date: Dec 1999
Location: Austin, TX, USA
Posts: 7,720
|
Re: how tough are our rearends
In my experience, the truck 12 bolt is sufficient for a 1/2 ton 2 wheel drive truck that is used as a 1/2 ton 2 wheel drive truck. OK in a 4x4 if you don't put big tires on it or have a manual trans. And if you have an orignal Eaton posi and not a Gov-Bomb.
When we got the '72 Jimmy in '77 it had 113k miles on it. My dad was turning it off in the driveway and letting the clutch out simultaneously when it backfired. And broke two teeth on the pinion gear crazy enough. Put a junkyard one in at that point, 130k miles or so, and ran it up to around 200k at which point the pinion bearing went out. Combined all the parts into one and ran it until 270k or so. Swapped in a Gov-Lok and a set of 4.10's from a parts truck once I put 33's and then 35's on it. Broke ring gear in about 15k miles, my brother had borrowed it so who knows what he was up to. Had diff rebuilt with 4.10 thick gear on the original Eaton posi. Was gettin' on it a little and it wheel hopped. Twice. And broke the Eaton posi in 1/2 across the window. Swapped other original Eaton in on new gear set, and broke ring gear. Turns out two much runout on the posi unit and the first new gear set install I had done. Had posi trued up in lathe and ANOTHER new 4.10 gear set. Ran that until 340k miles or so. Then ditched the 12 bolt completely which now had ridiculous amounts of bearing wear and bent spring perches as well . Put in a semi-float 9.5" form a 3/4 ton Suburban which is unbelievably stout compared to the 12t , and it will most likely go the distance considering how truck gets driven now. So, 7? 8? 12 bolts in the truck. ![]() ![]() The 8.5" 10 bolt with 30 spline axles is a strong as a car 12 bolt (12p). The fewer ring gear bolts are larger in diameter and reversed threaded compared to the 12t or p, so that is a push. The ring gear diameter at 8 1/2" vs. 8 7/8" is almost a push, and pinion diameter on the 8.5 is same as the 12p. Big tires will do in all of them with stock style/strength components.
__________________
44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax |
![]() |
![]() |
![]() |
#14 |
Senior Member
Join Date: Mar 2002
Location: 12 Miles South of Des Moines, Iowa
Posts: 359
|
Re: how tough are our rearends
Depends on how you are going to use it. My 69 was used as a chassis with a camper on it, I have no idea how many miles it has on it, the odometer has rolled over at least once and judging by the wear on the original 292 maybe twice. I have never had a problem with it and it is now behind a 327 making about 400ft/lbs of torque. I used to be quite...spirited with it when I was in high school. The axle is rated for 3750lbs. I once by mistake hauled 2 tons of pea gravel in the bed for 40 miles and it has never given me a problem. I have an original Eaton Posi to put in it and I'm going to replace all the bearings as a preventative measure but I plan to keep running it. Just a few specs, 327 400ft/lbs tq, sm465 granny low 4 speed, (soon to have us gear overdrive), 3.73 gears, 31x10.5 tires.
If that wasn't enough, my grandfather was a heavy equipment operator/mechanic, he had a 67 half ton, sm420 granny low trans, and 3.73 posi. It hauled over a ton of fuel, tools, fluids and parts every day of it's life over some pretty tough terrain for years. The truck was wrecked and then the box and rear were made into a trailer, they just junked it because the box rotted out, but the rear is still fine. In fact, that is what my posi is from. I took it out and put in an open carrier and a junk set of axle sidegears just to keep the axles in. I have no question that it will handle anything I will throw at it. But i'm not drag racing either.
__________________
69 C-10, 340HP 327 55 chevy 4 door 150 47 Willys CJ-2A 05 Harley Night Train 06 1200 Sportster (Wife's bike) 70 Honda CL350 OIF2 & OIF7 Veteran ![]() Nathan & Tiffany |
![]() |
![]() |
![]() |
#15 |
Old Skool Club
![]() Join Date: Jun 2001
Location: Benton, AR "The Heart of Arkansas"
Posts: 10,880
|
Re: how tough are our rearends
If you have a need, Currie makes their Ford 9-inch rear ends with whatever lug pattern you want on the axles. I've read plenty of times, of folks using those 9-inch rear ends in plenty of high-perf apps.
We used Taylor-Dunn electric vehicles at ALCOA. They had narrowed 9-inch rear ends, modified to run electric motors. I have seen them abused in just about every possible way and never a failure. Motors did fail, but not the rear ends. Oh, those were 36-volt motors and they had plenty of torque, so the gears would have taken the brunt of the load. Alway wanted to get one and change out the "punkin" and use it with some wide wheels and tires in a narrowed chassis....seems like those rearends were less than 40 inches, hub-to-hub.
__________________
Member Nr. 2770 '96 GMC Sportside; 4.3/SLT - Daily driven....constantly needs washed. '69 C-10 SWB; 350/TH400 - in limbo The older I get, the better I was. |
![]() |
![]() |
![]() |
#16 |
Registered User
Join Date: Nov 2008
Location: Italy
Posts: 1,278
|
Re: how tough are our rearends
I took for granted that my 1/2 ton rear (12 bolt 71-72) would go one without checking on it. It was literally the only thing I didn't refurbish or replace with new. The first time I tried to take it for a 2 hr road trip she died on me. It was a mess! Only the housing was salvageable. I had it completely rebuilt with Eaton posi, 4.11s, new axles, bearings and seals. Now I feel she'll go another 40+ years.
__________________
'68 C-10 SWB 383 Stroker (Sold 3/2/2013) '87 R2500 LWB 454 TBI converted to Carb ![]() |
![]() |
![]() |
![]() |
#17 |
Registered User
Join Date: Nov 2011
Location: Jones Creek, Texas
Posts: 38
|
Re: how tough are our rearends
guess i didn't give enough info on the original post...69 half ton 2 wheel drive. just had engine rebuilt 350 bored .060, cam, not sure what kind of hp or torque its gonna make. Just curious about weak links in drive train. Trans is a th350 with shift kit.
|
![]() |
![]() |
![]() |
#18 |
Registered User
![]() Join Date: Jan 2007
Location: Ill.
Posts: 584
|
Re: how tough are our rearends
I'll chime in here, My 72 has a 69 12 bolt posi in it i run at the track i bought the 69 for parts for 250.00 and then found it had the posi. so anyways my truck runs 8.90's 1/8 mile all day with a 350 aluminum heads 750 holley with a small cam pretty damn peppy so the only thing ive done to the rearend was install 4.56 behind the tci street fighter 400 tranny it still has c-clips and a two piece drive shaft that ive tried like hell to break leaving the line at 3000 rpm with 8-10 pounds of pressure in my mickey thompson et streets I havent been to the track for awhile been workin on my 67 alot So as far as im concrened these 12 bolts kick a55
__________________
Hi everyone, It's nice to know there's other people just as crazy about these old trucks as I am. ![]() |
![]() |
![]() |
![]() |
#19 |
Registered User
Join Date: Dec 2009
Location: Ste. Genevieve, MO
Posts: 526
|
Re: how tough are our rearends
I have a HO-52 and its a TANK!
|
![]() |
![]() |
![]() |
#20 |
Registered User
Join Date: Dec 1999
Location: Austin, TX, USA
Posts: 7,720
|
Re: how tough are our rearends
Big tires along with big power, or at least reasonable power in a high traction environment will find the weak link. Wheel hop will destroy it pronto.
I've built 8 1/2" 10 bolts for drag cars. The last one ran 10 teens at 126 mph behind a 462 Pontiac in a 3000# Firebird. No parts were stock, but I've built several for high 10/low 11 second cars with all stock parts but gears and some of them had hundreds of passes on them. So they can be built to take some power, and so can the 12t. One way to look at it, is the 12t is not in demand to be swapped into anything to beef up what's already there...
__________________
44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax |
![]() |
![]() |
![]() |
#21 |
Newbee
Join Date: Jan 2010
Location: Phoenix, Arizona
Posts: 1,406
|
Re: how tough are our rearends
Just swapped out the original 10 bolt in my 69. It had over 500,000 miles on it, and I remember replacing the wheel bearings twice. As I was taking it apart for it's demise, it had a tooth missing from the ring gear.
They are pretty tough! |
![]() |
![]() |
![]() |
Bookmarks |
|
|