Broke the rearend.

[corvette6698512]

Hey guys, Im new to the forums. My name is Chris. I have a '68 pickup that has been a good truck sofar. I decided to mess around with it a little bit to see if it would do a burnout. Put it in 1st(its a 3 speed with 292) and dumped the clutch(not really sidestep, just released it quickly) First time was awesome. Didnt break a sweat, but the second time made some bad noises. The driveline was dragging, and the diff on the 12 bolt was turned up way further then it should be. It broke the welds that keep the diff from twisting. Iv never seen this or heard of it. I don't think it will be too hard to fix, but I thought id share my little mishap. I think I can turn it back down and weld it back together. If not, i'll look for another 12bolt. No more beatings for this old pickup, I like it too much to keep breaking it. Pics:

[shaneo2112RUSH]

Wow!! alot of tourqe or just old age!!
I,m not suprised the axle welds sheered off!! that was a weekness in the GM axles!!
I would take it to a drive line shop to make shure the axles strait across!

Love the One Tire Fire Mark!!

[gonzo6869]

NICE! It showed you it has no prob laying down rubber. On the other hand it showed you it has no prob hooking up either
Hope its an easy fix, keep us updated.

[corvette6698512]

I suppose I beat on it a little harder then I should have. This old 292 sure runs strong. anyways, A driveline shop huh? I was hoping I wouldn't have to pull it lol.

[americanmusc1e]

WOW, I broke the spider gears in mine because I did two many a one-wheeled burnouts with my 383, but I never suspected that you could break those welds without breaking an axle or the diff carrier.


this is what I did


BTW, welcome and congrats on a fine looking truck

[corvette6698512]

Thanks for the great replys. I really do like this truck. I sold my subaru to get it, and I don't regret it at all. I know i didn't break the diff or the trans. I think I got lucky on this one. I have heard the 3 speed column shift transmissions don't take too much abuse. Im hoping to have it fixed in the next few days. Thanks again.

Chris

[70cst]

Best of luck...Sorry to hear of your mishap.

[capev86]

maybe swap axles with a good 10 bolt (trailing arm perches needed and shock mounts moved). i hear the 12 bolt is not as rugged as the 10 bolt. also remember nothing lasts long when you beat on it. make sure everything is in tip top shape and also maybe use synthetic fluid (diffs get hot). supertech, mobil 1 and several other brands make it. i put royal purple in my the 3onthetree in my 72 burb 3/4 ton and plan to change out the rear diff fluid in the HO52 when i swap in my 4.10 third memeber. i will be towing with my truck and the drivetrain only has 74,000 gentle miles and i plan to keep it in that condition.

[usmcchevy]

Impressive! I've taken out some rearends but never done that....yet. I'd find another 12 bolt in a junk yard and swap it in, no fab required. Unless you like to modify then I'd skip the 10 bolt and go for a 9"

[GASoline71]

Originally Posted by capev86

maybe swap axles with a good 10 bolt (trailing arm perches needed and shock mounts moved). i hear the 12 bolt is not as rugged as the 10 bolt.

Don't know where you heard that... the 12 bolt truck rear end is a good rear end with a larger ring gear than a 10 bolt. The axles are bigger too...

Gary

[usmcchevy]

Originally Posted by GASoline71

Don't know where you heard that... the 12 bolt truck rear end is a good rear end with a larger ring gear than a 10 bolt. The axles are bigger too...

Gary

It has something to do with the 10 bolt having a larger pinion shaft.

[GASoline71]

It might have a larger pinion shaft but is a weaker unit all together. If they were that solid of a rear end, there would be more people swappin' out 12 bolts for 10 bolts...

Gary

[corvette6698512]

I dont plan on doing anything like that again. It was my stupidity, and I knew it might break. I'll look around for another 12bolt and be nice to it.

[highperf4x4]

Welcome to the forum.

I pulled a similar stunt but I broke the front yoke off the driveshaft in my 4x4.

[Shaky]

There's just a puddle weld that holds the tube into the main housing. That's why the differential shops do a 360 degree weld on the tubes when building up a performance rear.

Never underestimate the ability of a 292 to make gobs of low-end torque.

[Sublvr72]

kids....

lol


if there's no damage to the axle other than the mounts, just weld it back down after you set it. I'm guessing you broke more than that though...

[bigsnookmaster]

Originally Posted by Sublvr72

kids....

lol


if there's no damage to the axle other than the mounts, just weld it back down after you set it. I'm guessing you broke more than that though...

I agree, if it isn't leaking, weld it. I would tack it in, spin the yolk and see if the rear is making any noise. If all else fails, replace it. But it would suck if you replace it and all it needed was to be re-welded

[junkyardjohn]

[QUOTE=bigsnookmaster;3785577]I agree, if it isn't leaking, weld it. I would tack it in, spin the yolk and see if the rear is making any noise. If all else fails, replace it. But it would suck if you replace it and all it needed was to be re-welded[/QUOTE YOU BET.. I'D LOOSEN THE U-BOLTS , TURN IT BACK WHERE THE OLD WELD MARKS LINE UP & WELD IT. HECK YOU ONLY GAMBLE 15 MINUTES. YOU JUST MIGHT GET LUCKY. IT'S SURE WORTH A TRY. JOHN

[eagleuh1]

Did it brake the u-joints or yoke at the rear-end, thats a lot of angle for a spinning mass. Also the first time for seeing this happen. Awsome burnout man!!! Fix what you got, as long as the tubes didn't bend or crush/twist up where they go into the diff. housing or at the perches. Good luck.

[big_al_71]

nice peg leg burn out

[FRENCHBLUE72]

Power of the six popper....

[chas350]

Hey nice job! lol
I broke the spring perch's off my axel on the 70 camaro I had years ago. Thats what happens when you put slicks on it at the drag track and it really hooks up after a burnout lol. The diff twisted up so hard,the u joint broke and the yoke punched a hole through the floor. HAHA that was the last time I took it to the track!
Another time I blew the rear up and broke the c clips, both axels slid out and set the diff almost on the road, what a sight that was through the side mirrors with the wheels/tires running about 2' outside the fenders! That was funny, my friends never let me forget that one.

[brad_man_72]

definatly want to make sure the driveshaft is still relativley straight, make sure the pinion and pinion yoke arrent damaged.
hell id bolt the rear end down and take a gentle ride around the block before i even bothered welding it.

who says a I6 couldnt do a burnout, heres a memeber winning the 09 midwest all truck nationals burnout contest with his 250 w a 3 speed.

YouTube- Sep 12 2009 VID00007

[capev86]

yeah.....straight 6's are very efficient and make great low end torque, especially the big boy 292. that's why they put an I6 in the trailblazer instead of sticking with a v6 like in the old s10's. with or without work, they make great towing engines due to their low rpm performance characteristics compared to V engines. the 292 also has a 4-1/8 inch stroke which is pretty much unmatched even by modern stroker engines.

you can hot rod up the 292 with a 4 barrel intake, split exhaust manifold to go dual exhaust. that magnaflow x-pipe ss exhaust for the 67-72 would probably work great with a little tweaking to match up. there are also roller valvetrains and you can put a petronix kit in the factory distributor for electronic ignition. they even have a TBI system for the 292 i hear.

i'd love to put a modernized 292 in an early 50's burb or panel truck (i like the 1 ton extended wheelbase). but i have my 72 burb and many other projects needing my time and money.

[corvette6698512]

So I found out its a lot harder to twist that back to the stock location then just "twist it back". I think I will have to put a chain around the yoke and under the diff and see if I can pull that back and twist it down.