12 bolt axle carnage

[66skylarkpost]

this is out of a buddy's ' 85 long box with 33" bfg all terrains . he swaped out the axles and springs last year from an old farm beater ( 3.42 10-bolt and 12 bolt/ 6 inch superlift front springs and 4 " springs and 2 "blocks out back ) . then i guess last week he was tearing it up around town , and luckily he was near his house and heared a loud " clank " . locked it in 4 wheel and limped it home . i just thought i'd share

[vtblazer]

A little surprised 33's did that to a 12 bolt.

Sounds like lots of tire smoke with a bad case of wheel hop thrown in.

[Zoomad75]

I'm thinking "tearing it up" is the right term. He must have been pushing the throttle through the floor to end up with that!

I've put lots of street miles on my 12 bolt with 33's and 35's and never broke it. But then again, I'm not out racing anyone either or really hammering on it hard.

[66skylarkpost]

i'm sure he was tearing it up .it has a strong early 350 with 993 heads. when he called me , i was like " what are you talking about ?" ive ran many 12 bolts with 33's and 35's , the most ive seen is bent wheel flanges . ive broken teeth off gears , busted cross pins and carriers , and even broke off pinion yokes , but never broke and axle . the axles my buddy have are from an old farm truck , where it looked like it was rode hard and put away , ya know !

[Elwayno]

Going from spinning to sticking on the street is very abrupt. Had a buddy spinning in the dirt from the side of the road and come on to the pavement and snap both axles when the tires suddenly gripped.

[Zoomad75]

Originally Posted by Elwayno

Going from spinning to sticking on the street is very abrupt. Had a buddy spinning in the dirt from the side of the road and come on to the pavement and snap both axles when the tires suddenly gripped.

That's probably how it happened. 33's have a pretty big contact patch so when it grabs, the torque has to go somewhere. I helped a guy snap his 10 bolt rear axle that way. During a block party for the Woodward Dream cruise back in Detroit we would all do burnouts on our street. One of the party attendees decides to try out his 84 K10 that's pretty much stock down to the 305, but lifted 4" and sitting on 33's. No amount of water poured out would help the 305 spin the right rear (open diff too). 5 of us lift up on the right rear corner of the bed/bumper to take enough load off of the tire to get it to spin. Just as planned it does and the smoke begins to roll. The five of us lifting see smoke and figure now that it's spinning it should keep spinning when we let go. I kid you not to say as soon as we let go the tire stopped spinning (the guy had his foot buried in the throttle) and we here a nice loud metallic *SNAP*. That was it! He dove a few blocks home on the front axle with a passenger in the bed to shove the wheel/axle assembly back into the axle when it started to wobble out.

We all warned him it was high probability that he would snap an axle shaft but he went for it. I laughed my arse off.

[70rs/ss]

That is why the $250 upgrade to new aftermarket axles is always a great idea!

[OLDCHEV4X4]

I race a 12 bolt in my 72 Blazer with 33's. Only thing i ever broke was the spider gears.

[jkaylor68gmc]

Ouch! That had to hurt,

Your axle called and it hates you.

[ND_guy]

Four years ago in my 77 k5, the highway was a mix of glare ice and dry pavement. I was going about 50mph and locked in 4x4. I was on a dry section of road when the rear gear set locked up and instantly it broke the left 12 bolt shaft. Since the t-case was locked in a front axle steering u-joint and yoke shattered, giving me zero wheel drive. That day was very expensive. I had to buy a flatbed tow and a junk suburban for both axles. The axle swap was done in 10degree North Dakota and I don't plan on ever doing it again!

[earl87gta]

time for the 14blt

[hilbilly]

two Yukon 4340 fronts w/ CTM joints. snaped both at the same time. Good thing, 5 year warrenty